Purpose:Regular exercise can reduce incidence and progression of breast cancer,but the mechanisms for such effects are not fully understood.The purpose of this study was to examine the mechanisms behind the protective...Purpose:Regular exercise can reduce incidence and progression of breast cancer,but the mechanisms for such effects are not fully understood.The purpose of this study was to examine the mechanisms behind the protective effects of exercise.Methods:We used a variety of rodent and human experimental model systems to determine whether exercise training can reduce tumor burden in breast cancer and to identify mechanism associated with any exercise training effects on tumor burden.Results:We show that voluntary wheel running slows tumor development in the mammary specific polyomavirus middle T antigen overexpression(MMTV-PyMT)mouse model of breast cancer but only when mice are not housed alone.We identify the proteoglycan decorin as a contraction-induced secretory factor that systemically increases in patients with breast cancer immediately following exercise.Moreover,high expression of decorin in tumors is associated with improved prognosis in patients,while treatment of breast cancer cells in vitro with decorin reduces cell proliferation.Notwithstanding,when we overexpressed decorin in murine muscle or injected recombinant decorin systemically into mouse models of breast cancer,elevated plasma decorin concentrations did not result in higher tumor decorin levels and tumor burden was not improved.Conclusion:Exercise training is anti-tumorigenic in a mouse model of luminal breast cancer,but the effect is abrogated by social isolation.The proteoglycan decorin is an exercise-induced secretory protein,and tumor decorin levels are positively associated with improved prognosis in patients.The hypothesis that elevated plasma decorin is a mechanism by which exercise training improves breast cancer progression in humans is not,however,supported by our pre-clinical data since elevated circulating decorin did not increase tumor decorin levels in these models.展开更多
Chronic inflammation has increasingly been acknowledged as a hallmark feature of several progressive neurodegenerative disorders. Accruing evidence indicates that sustained inflammation compromises the core neuroprote...Chronic inflammation has increasingly been acknowledged as a hallmark feature of several progressive neurodegenerative disorders. Accruing evidence indicates that sustained inflammation compromises the core neuroprotective mechanisms underlying neural injury in Alzheimer's disease (AD) and retinal neurodegenerative disorders.展开更多
Extracellular deposits of the amyloid-beta peptide(Aβ) are known as the main pathological hallmark of Alzheimer's disease. In Alzheimer's disease, neurons are injured and die throughout the brain, a process i...Extracellular deposits of the amyloid-beta peptide(Aβ) are known as the main pathological hallmark of Alzheimer's disease. In Alzheimer's disease, neurons are injured and die throughout the brain, a process in which Aβ neurotoxicity is considered to play an important role. However, the molecular mechanisms underlying Aβ toxicity that lead to neurodegeneration are not clearly established. Here we have elucidated the molecular pathways and networks which are impacted by Aβ in neurons using SH-SY5Y human neuroblastoma cells as a model. These cells were treated with Aβ_(1–42) peptides to study changes in biochemical networks using tandem mass tag labeled quantitative proteomic technique followed by computational analysis of the data. The molecular impacts of Aβ on cells were evident in a time-and dose-dependent manner, albeit the duration of treatment induced greater differential changes in cellular proteome compared to the effects of concentration. Aβ induced early changes in proteins associated with lysosomes, collagen chain trimerization and extracellular matrix receptor interaction, complement and coagulation cascade, oxidative stress induced senescence, ribosome biogenesis, regulation of insulin-like growth factor transport and uptake by insulin-like growth factor-binding protein. These novel findings provide molecular insights on the effects of Aβ on neurons, with implications for better understanding the impacts of Aβ on early neurodegeneration in Alzheimer's disease pathology.展开更多
Endometriosis is a common chronic gynecological disease with endometrial cell implantation outside the uterus.Angiogenesis is a major pathophysiology in endometriosis.Our previous studies have demonstrated that the pr...Endometriosis is a common chronic gynecological disease with endometrial cell implantation outside the uterus.Angiogenesis is a major pathophysiology in endometriosis.Our previous studies have demonstrated that the prodrug of epigallocatechin gallate(ProEGCG)exhibits superior anti-endometriotic and anti-angiogenic effects compared to epigallocatechin gallate(EGCG).However,their direct binding targets and underlying mechanisms for the differential effects remain unknown.In this study,we demonstrated that oral ProEGCG can be effective in preventing and treating endometriosis.Additionally,1D and 2D Proteome Integral Solubility Alteration assay-based chemical proteomics identified metadherin(MTDH)and PX domain containing serine/threonine kinase-like(PXK)as novel binding targets of EGCG and ProEGCG,respectively.Computational simulation and BioLayer interferometry were used to confirm their binding affinity.Our results showed that MTDH-EGCG inhibited protein kinase B(Akt)-mediated angiogenesis,while PXK-ProEGCG inhibited epidermal growth factor(EGF)-mediated angiogenesis via the EGF/hypoxia-inducible factor(HIF-1a)/vascular endothelial growth factor(VEGF)pathway.In vitro and in vivo knockdown assays and microvascular network imaging further confirmed the involvement of these signaling pathways.Moreover,our study demonstrated that ProEGCG has superior therapeutic effects than EGCG by targeting distinct signal transduction pathways and may act as a novel antiangiogenic therapy for endometriosis.展开更多
Fragile X syndrome(FXS)is the most prevalent inherited intellectual disability,resulting from a loss of fragile X mental retardation protein(FMRP).Patients with FXS suffer lifelong cognitive disabilities,but the funct...Fragile X syndrome(FXS)is the most prevalent inherited intellectual disability,resulting from a loss of fragile X mental retardation protein(FMRP).Patients with FXS suffer lifelong cognitive disabilities,but the function of FMRP in the adult brain and the mechanism underlying age-related cognitive decline in FXS is not fully understood.Here,we report that a loss of FMRP results in increased protein synthesis of histone acetyltransferase EP300 and ubiquitinationmediated degradation of histone deacetylase HDAC1 in adult hippocampal neural stem cells(NSCs).Consequently,FMRPdeficient NSCs exhibit elevated histone acetylation and age-related NSC depletion,leading to cognitive impairment in mature adult mice.Reducing histone acetylation rescues both neurogenesis and cognitive deficits in mature adult FMRPdeficient mice.Our work reveals a role for FMRP and histone acetylation in cognition and presents a potential novel ther⁃apeutic strategy for treating adult FXS patients.展开更多
Calmodulin from Homo sapiens is an α-helical calcium-binding protein that expresses to high levels in E. coli. When the N-terminus of a calmodulin variant is bound to Ca2+, it undergoes a conformational change, expos...Calmodulin from Homo sapiens is an α-helical calcium-binding protein that expresses to high levels in E. coli. When the N-terminus of a calmodulin variant is bound to Ca2+, it undergoes a conformational change, exposing hydrophobic pockets. This property can be utilized for purification purposes, as these pockets bind to phenyl sepharose resin with high affinity. Washing with EDTA chelates the Ca2+ ions from the protein, inducing a conformational change back to the more folded state and eluting the protein from the column. We describe herein the use of a protein expression and purification technique using the calmodulin variant and a short linker for proteolytic cleavage by the mutant NIa-Pro tobacco etch virus protease. We have shown this approach to be useful in obtaining purified quantities of various small proteins that could not be expressed using other methods, including high enough concentrations of a designed WW domain protein for NMR structural analysis. We have also obtained promising results on the usefulness of this procedure to express and purify zinc finger proteins without the addition of zinc ions or other cofactors.展开更多
Aims： High-quality DNA as input material for a NGS （next-generation sequencing） workflow is essential for the successful preparation of a DNA library. Additionally, DNA quality has a strong impact on sequencing res...Aims： High-quality DNA as input material for a NGS （next-generation sequencing） workflow is essential for the successful preparation of a DNA library. Additionally, DNA quality has a strong impact on sequencing results. Therefore, it is important to include QC （quality control） steps to assess size, concentration, molarity, and integrity of the DNA during the workflow. Material and Methods： The WES （Whole Exome Sequencing） workflow at the Genomics and Proteomics Core Facility of DKFZ （the German Cancer Research Center） was performed with several QC steps： QC of the input material, QC of intermediate products during library preparation, and QC of final libraries. The Agilent 4200 TapeStation system, which offers automated sample processing, was used to evaluate quantity, size, molarity, and integrity of the samples. Key Findings： The Agilent Genomic DNA ScreenTape assay offers an unbiased genomic DNA integrity assessment, which enables protocol adaption for optimized library preparation, for example, selection of a suitable shearing protocol. Additionally, QC steps during library preparation such as evaluation of library size, concentration, and molarity ensure maximal sequencing output. Significance： The automated and fast high-throughput analysis of genomic DNA with the 4200 TapeStation system helps to save labor time and costs. Additionally, the easy-to-use system can be integrated as a QC tool into the NGS workflow to ensure successful library preparation. QC steps enable the confirmation of suitable library size and concentration for the workflow.展开更多
The use of adipose-derived cells as a treatment for a variety of diseases is becoming increasingly common. These therapies include the use of cultured mesenchymal stem cells (MSCs) and freshly isolated stromal vascula...The use of adipose-derived cells as a treatment for a variety of diseases is becoming increasingly common. These therapies include the use of cultured mesenchymal stem cells (MSCs) and freshly isolated stromal vascular fraction (SVF) alone, or in conjunction with other cells such as adipocytes. There is a substantial amount of literature published on the therapeutic properties of MSCs and their secretions as the main driver of their therapeutic effect. However, there is little data available on the therapeutic potential of secretions from SVF, either with or without adipocytes. We investigated the ability of secretions from human adipose SVF alone and the SVF co-cultured with adipocytes as a proxy for cell therapy, to ameliorate an inflammatory disorder. This ethics approved study involved the treatment of collagen antibody-induced arthritis (CAIA) in mice with secretions from SVF, SVF co-cultured with adipocytes, or a vehicle control via both intravenous (IV) and intramuscular (IM) routes. Treatment outcome was assessed by paw volume, ankle size and clinical arthritis score measurements. Serum samples were obtained following euthanasia and analysed for a panel of 32 mouse cytokines and growth factors. The dose and timing regime used for the IM administration of both human secretion mixtures did not significantly ameliorate arthritis in this model. The IV administration of SVF adipocyte co-culture secretions reduced the paw volume, and significantly reduced the ankle size and clinical arthritis score when compared to the IV vehicle control mice. This was a superior therapeutic effect than treatment with SVF secretions. Furthermore, treatment with SVF adipocyte coculture secretions resulted in a significant reduction in serum levels of key cytokines, IL-2 and VEGF, involved in the pathogenesis of rheumatoid arthritis. Therefore, the SVF cocultured with adipocytes is an attractive therapeutic for inflammatory conditions.展开更多
Metastatic hormone receptor-positive(HR+),human epidermal growth factor receptor 2-negative(HER2−)breast cancer often develops resistance to first-line treatment,typically combining cyclin-dependent kinase 4 and 6 inh...Metastatic hormone receptor-positive(HR+),human epidermal growth factor receptor 2-negative(HER2−)breast cancer often develops resistance to first-line treatment,typically combining cyclin-dependent kinase 4 and 6 inhibitors(CDK4/6i)with hormone therapy(HT)[1,2].After an initial response,most patients become resistant,and compensatory mechanisms are not fully uncovered[3].展开更多
The hypothesis that capping dietary starch:protein ratios would enhance the performance of broiler chickens offered reduced-crude protein(CP)diets was tested in this experiment.A total of 432 off-sex,male Ross 308 chi...The hypothesis that capping dietary starch:protein ratios would enhance the performance of broiler chickens offered reduced-crude protein(CP)diets was tested in this experiment.A total of 432 off-sex,male Ross 308 chicks were allocated to 7 dietary treatments from 7 to 35 d post-hatch.The experimental design consisted of a 3×2 factorial array of treatments with the seventh treatment serving as a positive control.Three levels of dietary CP(197.5,180.0 and 162.5 g/kg)with either uncapped or capped dietary starch:protein ratios constituted the factorial array of treatments,whilst the positive control diet contained 215.0 g/kg CP.The positive control diet had an analysed dietary starch:protein ratio of 1.50 as opposed to a ratio of 1.68 in the uncapped 197.5 g/kg CP diet and 1.41 in the corresponding capped diet and the capped 197.5 g/kg CP diet displayed promise.The growth performance this diet matched the positive control but outperformed the uncapped 197.5 g/kg CP diet by 10.4%(2,161 vs.1,958 g/bird;P=0.009)in weight gain,by 3.10%(3,492 vs.3,387 g/bird;P=0.019)in feed intake on the basis of pairwise comparisons and numerically improved FCR by 4.04%(1.616 vs.12684).However,the growth performance of birds offered the 180.0 and 162.5 g/kg CP dietary treatments was remarkably inferior,irrespective of dietary starch:protein ratios.This inferior growth performance was associated with poor feathering and even feather-pecking and significant linear relationships between feather scores and parameters of growth performance were observed.The amino acid profile of feathers was determined where cysteine,glutamic acid,glycine,proline and serine were dominant in a crude protein content of 931 g/kg.Presumably,the feathering issues observed were manifestations of amino acid inadequacies or imbalances in the more reduced-CP diets and consideration is given to the implications of these outcomes.展开更多
The Liverpool Plains is a fertile agricultural region in New South Wales, Australia. Two sorghums from the2009 Liverpool Plains harvest, sorghums #3 and #5, were extensively characterised which included concentrations...The Liverpool Plains is a fertile agricultural region in New South Wales, Australia. Two sorghums from the2009 Liverpool Plains harvest, sorghums #3 and #5, were extensively characterised which included concentrations of kafirin and phenolic compounds plus rapid visco-analysis(RVA) starch pasting profiles. Diets based on these two sorghums were formulated to be iso-nitrogenous and iso-energetic and were offered to male Ross 308 broiler chicks from 7 to 28 days post–hatch as either intact pellets or reground mash following steam-pelleting at conditioning temperatures of either 65 or 97°C. Thus the feeding study consisted of a 2×2×2 factorial array of dietary treatments: two sorghum varieties, two feed forms and two conditioning temperatures. Each of the eight treatments was replicated six times with six birds per replicate cage.Assessed parameters included growth performance, nutrient utilisation, apparent starch and protein(N) digestibility coefficients and disappearance rates from the distal jejunum and distal ileum. Intact pellets supported higher(P <0.001) feed intakes and weight gains by 9.83 and 9.08%, respectively, than reground mash diets. Feed conversion ratios of broilers offered diets steam-conditioned at 97°C were 2.46% inferior(P <0.001) in comparison to 65°C diets and both apparent metabolizable energy(AME) and N-corrected AME(AMEn) were compromised. Broilers offered sorghum #3-based diets significantly(P <0.001) outperformed their sorghum #5 counterparts in terms of weight gain by 3.75%(1,334 versus 1,223 g/bird), FCR by 4.81%(1.524 versus 1.601), AME by 1.06 MJ(13.61 versus 12.55 MJ/kg), ME:GE ratio(ME:GE) by 4.81%(0.806 versus0.769) and AMEn by 1.03 MJ(12.38 versus 11.35 MJ/kg). The inferiority of sorghum #5 appeared to be associated with higher concentrations of kafirin(61.5 versus 50.7 g/kg) and conjugated phenolic acids,including ferulic acid(31.1 versus 25.6 mg/g). There were no significant differences in jejunal and ileal starch and protein(N) digestibility coefficients between the two sorghums. However, starch to protein(N) disappearance rate ratios from the distal jejunum were significantly(P <0.001) correlated with ME:GE and AME. The multiple linear regression equations indicated that energy utilisation was enhanced by coupling rapidly digestible protein with slowly digestible starch, which suggests that bilateral bioavailability of starch and protein is pivotal to efficient energy utilisation.展开更多
The objective of the study was to investigate the possibility that tandem inclusions of a reducing agent and a protease may advantage chicken-meat production and to ascertain if the established benefits of including s...The objective of the study was to investigate the possibility that tandem inclusions of a reducing agent and a protease may advantage chicken-meat production and to ascertain if the established benefits of including sodium metabisulphite in sorghum-based diets extend to wheat-based diets. The study comprised a 2 x 2 x 2 factorial array of treatments in which either nutritionally iso-nitrogenous and isoenergetic wheat-or sorghum-based diets, without and with sodium metabisulphite(2.75 g/kg), without and with protease(1,000 units/kg) were offered to broiler chickens from 7 to 28 days post-hatch. The effects of dietary treatments on growth performance, nutrient utilisation, protein(N) and starch digestibility coefficients and digestive dynamics were determined. A preliminary investigation into the effects of two treatments on concentrations of free amino acids and glucose in the portal circulation was conducted. There was significant feed grain by sodium metabisulphite interactions(P = 0.03 to 0.005) for parameters of nutrient utilisation(AME, ME:GE ratios, N retention, AMEn). For example, sodium metabisulphite inclusions in sorghum-based diets enhanced AME by 0.18 MJ(12.47 versus 12.29 MJ/kg) but depressed AME by 0.43 MJ(11.88 versus 12.31 MJ/kg) in wheat-based diets. There was a linear relationship between starch:protein disappearance rate ratios in the distal ileum with weight gain(r =-0.484; P = 0.0012) indicating that condensed ratios(or absorption of more protein relative to starch) advantaged growth performance. Concentrations of free amino acids in the portal circulation or the post-enteral availability of certain amino acids, including the branched-chain amino acids, methionine, phenylalanine and threonine, were significantly correlated to FCR. For example, threonine concentrations were negatively correlated to FCR(r =-0.773; P = 0.005). Finally, tandem inclusions of sodium metabisulphite and protease in sorghum-based diets may hold merit but it appears that the established 'energy sparing' effects of sodium metabisulphite inclusions in sorghum-based diets are not duplicated in wheat-based diets.展开更多
This study determined the variations in protein digestibilities and digestion rates in broiler chickens offered diets containing 7 different meat and bone meals(MBM).A total of 252 male Ross 308 broiler chickens were ...This study determined the variations in protein digestibilities and digestion rates in broiler chickens offered diets containing 7 different meat and bone meals(MBM).A total of 252 male Ross 308 broiler chickens were offered 7 atypical diets largely based on maize and MBM from 24 to 28 d post-hatch.Each experimental diet was offered to 6 replicates with 6 birds per replicate cage.Excreta were collected in their entirety from 25 to 27 d post-hatch and on 28 d post-hatch.Digesta samples were collected from the proximal jejunum,distal jejunum,proximal ileum and distal ileum.Apparent digestibilities of protein were determined in each segment and apparent digestibilities of amino acids were measured in the distal ileum.There were significant differences in apparent protein digestibility coefficients in the proximal jejunum(P=0.006),where broiler chickens offered the high ash beef meal(diet 7)generated the lowest protein digestibility in the proximal jejunum(0.318).Similarly,there were significant differences in apparent digestibility coefficients in the distal jejunum(P<0.001)and distal ileum(P<0.001)but not in the proximal ileum.More pronounced differences were found in the disappearance rate of protein and there were significant differences in all 4 segments of the small intestine(P<0.001).Broiler chickens offered the high ash beef meal had the lowest protein disappearance rate(P<0.001).No difference was observed in the predicted protein digestion rate(P=0.486)but chickens offered the high ash beef meal had the lowest potential digestible protein(0.662,P=0.034)whereas the highest potential digestible protein(0.739)was detected in diet 5(containing a beef meal).This study contributed to the establishment of a preliminary database to include digestion rates of starch and protein into practical diet formulation.展开更多
As lowering crude protein(CP)in poultry diets continues to minimize amino acid excess,it is important to understand the limiting order of amino acids and the impact of their deficiencies.Therefore,a pair of experiment...As lowering crude protein(CP)in poultry diets continues to minimize amino acid excess,it is important to understand the limiting order of amino acids and the impact of their deficiencies.Therefore,a pair of experiments were conducted to observe the effects of individual amino acid deletions on growth performance,carcass traits,and nutrient utilization.Both experiments involved 3 control diets based on wheat and soybean meal,including a 210.0 g/kg CP industry control(IC),186.7 g/kg CP positive control(PC)supplemented with feed-grade amino acids to match the IC amino acid profile,186.7 g/kg CP negative control(NC)with reducing N corrected apparent metabolizable energy(AMEN)by 0.5 MJ/kg and removing feed-grade amino acids beyond L-Lys-HCl,DL-Met,and L-Thr from PC.Ten deletion diets where the following supplemented amino acids were individually removed from the PC:Val,Ile,Leu,Trp,Arg,His,Phe t Tyr,glycine equivalence(Glyequi),Pro,and Energy(0.5 MJ/kg reduction in AMEN of the PC).All diets were formulated to contain similar concentrations of digestible Lys,total sulfur amino acid(TSAA)and Thr.Experimental diets were offered to broiler chickens from 15 to 22 d postehatch in a cage study(Exp.1)to gain digestibility and nutrient utilization data;whereas they were offered from 15 to 35 d post ehatch in a floor-pen study(Exp.2)to gain performance and carcass yield data.The removal of supplemented Val,Arg,and Ile resulted in reduction on broiler performance(P<0.05),and the removal of Val,Arg,Ile,and Glyequi negatively influenced carcass traits(P<0.05).Results from both experiments indicate that Val and Arg are co-limiting in wheat-soybean meal diets,but that Ile and Glyequi may potentially limit breast and thigh development.展开更多
In a previous experiment,male Ross 308 broiler chickens were offered dietary treatments with 3 levels of crude protein(222,193,165 g/kg)and 3 feed grains(ground maize,ground wheat,whole wheat)from 7 to 35 d post-hatch...In a previous experiment,male Ross 308 broiler chickens were offered dietary treatments with 3 levels of crude protein(222,193,165 g/kg)and 3 feed grains(ground maize,ground wheat,whole wheat)from 7 to 35 d post-hatch.Maize-based diets supported superior growth performance in comparison to wheatbased diets.Uric acid concentrations in excreta were retrospectively determined and related to total nitrogen(N)excreta concentrations.Uric acid concentrations ranged from 28.5 to 69.4 mg/g and proportions of uric acid-N to total excreta-N ranged from 27.4%to 42.6%in broiler chickens offered the 3×3 factorial array of dietary treatments.Proportions of uric acid-N to total N in excreta in birds offered the165 g/kg CP,maize-based diet were significantly lower by 10.6 percentage units(27.4%versus 38.0%;P=0.00057)than their wheat-based counterparts.Total excreta analysed had been collected from 35 to37 d post-hatch when feed intakes and excreta outputs were monitored.There were linear relationships between proportions of uric acid-N to total N in excreta in birds offered the three 165 g/kg CP diets with weight gain(r=-0.587;P=0.010),feed intake(r=-0.526;P=0.025)and feed conversion ratios(r=0.635;P=0.005).The possibility that increasing uric acid-N proportions in excreta is indicative of excessive ammonia accumulations compromising growth performance is discussed.The mean proportion of dietary glycine involved in uric acid excretion was 49.2%across all dietary treatments but ranged from 25.0%to 80.9%.Thus,the appropriate amount of dietary glycine is variable and largely dependent on the volume of uric acid synthesised and excreted.展开更多
Graded quantities of 1.38,2.76 and 4.14 g/kg L-methionine were included in a control diet formulated to contain 3.07 g/kg digestible methionine.Each of the 4 dietary treatments was offered to 6 replicate cages(initial...Graded quantities of 1.38,2.76 and 4.14 g/kg L-methionine were included in a control diet formulated to contain 3.07 g/kg digestible methionine.Each of the 4 dietary treatments was offered to 6 replicate cages(initially 8 birds per cage)from 1 to 21 d postehatch.The parameters assessed included growth performance,nutrient utilisation(apparent metabolisable energy[AME],AME:GE ratios,N retention,Ncorrected apparent metabolisable energy[AMEn]),apparent digestibility coefficients and disappearance rates of amino acids in the distal ileum.They also included free amino concentrations in systemic plasma(brachial vein)at 20 d postehatch and in hepatic tissue at 14 and 21 d postehatch.Graded L-methionine inclusions quadratically influenced weight gain(r=0.688;P=0.001)and FCR(r=0.780;P<0.001).It may be deduced from the quadratic regressions that 3.43 g/kg L-methionine supported maximum weight gain of 1,036 g/kg and 3.50 g/kg L-methionine minimum FCR of 1.193,from 1 to 21 d postehatch.The control diet contained specified levels of 3.07 g/kg digestible methionine and 13.0 g/kg digestible lysine.Thus,an inclusion of 3.465 g/kg L-methionine corresponded to a total of 6.535 g/kg methionine or a methionine-to-lysine ratio of 50.3,which is higher than standard recommendations.The implications of this and other outcomes of the present study are reported and discussed.展开更多
Phototropins （phot1 and phot2） are blue-light receptor kinases controlling a range of responses that optimize the photosynthetic efficiency of plants. Light sensing is mediated by two flavin-binding motifs, known as...Phototropins （phot1 and phot2） are blue-light receptor kinases controlling a range of responses that optimize the photosynthetic efficiency of plants. Light sensing is mediated by two flavin-binding motifs, known as LOVl and LOV2, located within the N-terminal region of the protein. Photoexcitation via LOV2 leads to activation of the C-terminal kinase domain and consequently receptor autophosphorylation. However, knowledge of the in-vivo phosphorylation sites for Arabidopsis phototropins is lacking and has impeded progress in elucidating the functional significance of receptor phos- phorylation. We have purified photl from Arabidopsis and identified the in-vivo sites of receptor phosphorylation by liquid chromatography tandem mass spectrometry. Arabidopsis-derived photl binds flavin mononucleotide as chromophore and is phosphorylated at four major sites located upstream of LOV2 （Ser^58, Ser^85, Ser^350, and Ser^410）, three of which are induced by blue light. Nevertheless, structure-function analysis indicates that the biological activity of photl can be attributed to a modular unit comprising the LOV2-kinase region of the protein. Thus, peptide regions upstream of LOV2, including the sites of receptor phosphorylation identified here, do not appear to be important for receptor signaling. By contrast, these regions may be necessary for maximizing stomatal performance and possibly light-induced relocalization of photl.展开更多
Rice (Oryza sativa)is the primary staple food source for more than half of the world's population.Proteins are active macromolecules and central to understanding biological molecular processes. Hence,it is necessa...Rice (Oryza sativa)is the primary staple food source for more than half of the world's population.Proteins are active macromolecules and central to understanding biological molecular processes. Hence,it is necessary to study all protein forms of plant genes so that their biological functions and roles in regulating important traits such as yield,quality,and responses to environmental stresses can be determined.展开更多
基金supported by an NHMRC Investigator Grant (APP1194141)supported by project grants from the NHMRC (APP1042465, APP1041760, and APP1156511)。
文摘Purpose:Regular exercise can reduce incidence and progression of breast cancer,but the mechanisms for such effects are not fully understood.The purpose of this study was to examine the mechanisms behind the protective effects of exercise.Methods:We used a variety of rodent and human experimental model systems to determine whether exercise training can reduce tumor burden in breast cancer and to identify mechanism associated with any exercise training effects on tumor burden.Results:We show that voluntary wheel running slows tumor development in the mammary specific polyomavirus middle T antigen overexpression(MMTV-PyMT)mouse model of breast cancer but only when mice are not housed alone.We identify the proteoglycan decorin as a contraction-induced secretory factor that systemically increases in patients with breast cancer immediately following exercise.Moreover,high expression of decorin in tumors is associated with improved prognosis in patients,while treatment of breast cancer cells in vitro with decorin reduces cell proliferation.Notwithstanding,when we overexpressed decorin in murine muscle or injected recombinant decorin systemically into mouse models of breast cancer,elevated plasma decorin concentrations did not result in higher tumor decorin levels and tumor burden was not improved.Conclusion:Exercise training is anti-tumorigenic in a mouse model of luminal breast cancer,but the effect is abrogated by social isolation.The proteoglycan decorin is an exercise-induced secretory protein,and tumor decorin levels are positively associated with improved prognosis in patients.The hypothesis that elevated plasma decorin is a mechanism by which exercise training improves breast cancer progression in humans is not,however,supported by our pre-clinical data since elevated circulating decorin did not increase tumor decorin levels in these models.
基金supported by Ophthalmic Research Institute of Australia(ORIA),NHMRC,Macquarie University,and the Australian Government’s National Collaborative Research Infrastructure Scheme(NCRIS)
文摘Chronic inflammation has increasingly been acknowledged as a hallmark feature of several progressive neurodegenerative disorders. Accruing evidence indicates that sustained inflammation compromises the core neuroprotective mechanisms underlying neural injury in Alzheimer's disease (AD) and retinal neurodegenerative disorders.
文摘Extracellular deposits of the amyloid-beta peptide(Aβ) are known as the main pathological hallmark of Alzheimer's disease. In Alzheimer's disease, neurons are injured and die throughout the brain, a process in which Aβ neurotoxicity is considered to play an important role. However, the molecular mechanisms underlying Aβ toxicity that lead to neurodegeneration are not clearly established. Here we have elucidated the molecular pathways and networks which are impacted by Aβ in neurons using SH-SY5Y human neuroblastoma cells as a model. These cells were treated with Aβ_(1–42) peptides to study changes in biochemical networks using tandem mass tag labeled quantitative proteomic technique followed by computational analysis of the data. The molecular impacts of Aβ on cells were evident in a time-and dose-dependent manner, albeit the duration of treatment induced greater differential changes in cellular proteome compared to the effects of concentration. Aβ induced early changes in proteins associated with lysosomes, collagen chain trimerization and extracellular matrix receptor interaction, complement and coagulation cascade, oxidative stress induced senescence, ribosome biogenesis, regulation of insulin-like growth factor transport and uptake by insulin-like growth factor-binding protein. These novel findings provide molecular insights on the effects of Aβ on neurons, with implications for better understanding the impacts of Aβ on early neurodegeneration in Alzheimer's disease pathology.
基金supported by the GRF RGC&CRF,Hong Kong(Grant Nos.:475012 and C5045-20 EF)HMRF,Hong Kong(Grant No.:03141386)+3 种基金ITF,Hong Kong(Grant No.:ITS/209/12)UGC Direct Grant 2011,2012,2021.032HKOG Trust Fund 2011,2014,2019the National Natural Science Foundation of China(Grant Nos.:81974225 and 82201823)。
文摘Endometriosis is a common chronic gynecological disease with endometrial cell implantation outside the uterus.Angiogenesis is a major pathophysiology in endometriosis.Our previous studies have demonstrated that the prodrug of epigallocatechin gallate(ProEGCG)exhibits superior anti-endometriotic and anti-angiogenic effects compared to epigallocatechin gallate(EGCG).However,their direct binding targets and underlying mechanisms for the differential effects remain unknown.In this study,we demonstrated that oral ProEGCG can be effective in preventing and treating endometriosis.Additionally,1D and 2D Proteome Integral Solubility Alteration assay-based chemical proteomics identified metadherin(MTDH)and PX domain containing serine/threonine kinase-like(PXK)as novel binding targets of EGCG and ProEGCG,respectively.Computational simulation and BioLayer interferometry were used to confirm their binding affinity.Our results showed that MTDH-EGCG inhibited protein kinase B(Akt)-mediated angiogenesis,while PXK-ProEGCG inhibited epidermal growth factor(EGF)-mediated angiogenesis via the EGF/hypoxia-inducible factor(HIF-1a)/vascular endothelial growth factor(VEGF)pathway.In vitro and in vivo knockdown assays and microvascular network imaging further confirmed the involvement of these signaling pathways.Moreover,our study demonstrated that ProEGCG has superior therapeutic effects than EGCG by targeting distinct signal transduction pathways and may act as a novel antiangiogenic therapy for endometriosis.
文摘Fragile X syndrome(FXS)is the most prevalent inherited intellectual disability,resulting from a loss of fragile X mental retardation protein(FMRP).Patients with FXS suffer lifelong cognitive disabilities,but the function of FMRP in the adult brain and the mechanism underlying age-related cognitive decline in FXS is not fully understood.Here,we report that a loss of FMRP results in increased protein synthesis of histone acetyltransferase EP300 and ubiquitinationmediated degradation of histone deacetylase HDAC1 in adult hippocampal neural stem cells(NSCs).Consequently,FMRPdeficient NSCs exhibit elevated histone acetylation and age-related NSC depletion,leading to cognitive impairment in mature adult mice.Reducing histone acetylation rescues both neurogenesis and cognitive deficits in mature adult FMRPdeficient mice.Our work reveals a role for FMRP and histone acetylation in cognition and presents a potential novel ther⁃apeutic strategy for treating adult FXS patients.
文摘Calmodulin from Homo sapiens is an α-helical calcium-binding protein that expresses to high levels in E. coli. When the N-terminus of a calmodulin variant is bound to Ca2+, it undergoes a conformational change, exposing hydrophobic pockets. This property can be utilized for purification purposes, as these pockets bind to phenyl sepharose resin with high affinity. Washing with EDTA chelates the Ca2+ ions from the protein, inducing a conformational change back to the more folded state and eluting the protein from the column. We describe herein the use of a protein expression and purification technique using the calmodulin variant and a short linker for proteolytic cleavage by the mutant NIa-Pro tobacco etch virus protease. We have shown this approach to be useful in obtaining purified quantities of various small proteins that could not be expressed using other methods, including high enough concentrations of a designed WW domain protein for NMR structural analysis. We have also obtained promising results on the usefulness of this procedure to express and purify zinc finger proteins without the addition of zinc ions or other cofactors.
文摘Aims： High-quality DNA as input material for a NGS （next-generation sequencing） workflow is essential for the successful preparation of a DNA library. Additionally, DNA quality has a strong impact on sequencing results. Therefore, it is important to include QC （quality control） steps to assess size, concentration, molarity, and integrity of the DNA during the workflow. Material and Methods： The WES （Whole Exome Sequencing） workflow at the Genomics and Proteomics Core Facility of DKFZ （the German Cancer Research Center） was performed with several QC steps： QC of the input material, QC of intermediate products during library preparation, and QC of final libraries. The Agilent 4200 TapeStation system, which offers automated sample processing, was used to evaluate quantity, size, molarity, and integrity of the samples. Key Findings： The Agilent Genomic DNA ScreenTape assay offers an unbiased genomic DNA integrity assessment, which enables protocol adaption for optimized library preparation, for example, selection of a suitable shearing protocol. Additionally, QC steps during library preparation such as evaluation of library size, concentration, and molarity ensure maximal sequencing output. Significance： The automated and fast high-throughput analysis of genomic DNA with the 4200 TapeStation system helps to save labor time and costs. Additionally, the easy-to-use system can be integrated as a QC tool into the NGS workflow to ensure successful library preparation. QC steps enable the confirmation of suitable library size and concentration for the workflow.
文摘The use of adipose-derived cells as a treatment for a variety of diseases is becoming increasingly common. These therapies include the use of cultured mesenchymal stem cells (MSCs) and freshly isolated stromal vascular fraction (SVF) alone, or in conjunction with other cells such as adipocytes. There is a substantial amount of literature published on the therapeutic properties of MSCs and their secretions as the main driver of their therapeutic effect. However, there is little data available on the therapeutic potential of secretions from SVF, either with or without adipocytes. We investigated the ability of secretions from human adipose SVF alone and the SVF co-cultured with adipocytes as a proxy for cell therapy, to ameliorate an inflammatory disorder. This ethics approved study involved the treatment of collagen antibody-induced arthritis (CAIA) in mice with secretions from SVF, SVF co-cultured with adipocytes, or a vehicle control via both intravenous (IV) and intramuscular (IM) routes. Treatment outcome was assessed by paw volume, ankle size and clinical arthritis score measurements. Serum samples were obtained following euthanasia and analysed for a panel of 32 mouse cytokines and growth factors. The dose and timing regime used for the IM administration of both human secretion mixtures did not significantly ameliorate arthritis in this model. The IV administration of SVF adipocyte co-culture secretions reduced the paw volume, and significantly reduced the ankle size and clinical arthritis score when compared to the IV vehicle control mice. This was a superior therapeutic effect than treatment with SVF secretions. Furthermore, treatment with SVF adipocyte coculture secretions resulted in a significant reduction in serum levels of key cytokines, IL-2 and VEGF, involved in the pathogenesis of rheumatoid arthritis. Therefore, the SVF cocultured with adipocytes is an attractive therapeutic for inflammatory conditions.
基金supported by grants fromthe National Fund for Scientific Research(NFSR-FNRS)Belgium(NES:PDR T.023020,CDR J.0178.22)the credit sectorial of the University of Liege(NES:FSR-S-SS-22/61,FSR-S-SS-22/64)the Foundation Contre le Cancer,Belgium(NES and AN:FCC-2022-181).
文摘Metastatic hormone receptor-positive(HR+),human epidermal growth factor receptor 2-negative(HER2−)breast cancer often develops resistance to first-line treatment,typically combining cyclin-dependent kinase 4 and 6 inhibitors(CDK4/6i)with hormone therapy(HT)[1,2].After an initial response,most patients become resistant,and compensatory mechanisms are not fully uncovered[3].
基金the guidance and financial support provided by AgriFutures Chicken-meatpart of project PRJ-010623 entitled"Utilisation of synthetic amino acids by poultry"
文摘The hypothesis that capping dietary starch:protein ratios would enhance the performance of broiler chickens offered reduced-crude protein(CP)diets was tested in this experiment.A total of 432 off-sex,male Ross 308 chicks were allocated to 7 dietary treatments from 7 to 35 d post-hatch.The experimental design consisted of a 3×2 factorial array of treatments with the seventh treatment serving as a positive control.Three levels of dietary CP(197.5,180.0 and 162.5 g/kg)with either uncapped or capped dietary starch:protein ratios constituted the factorial array of treatments,whilst the positive control diet contained 215.0 g/kg CP.The positive control diet had an analysed dietary starch:protein ratio of 1.50 as opposed to a ratio of 1.68 in the uncapped 197.5 g/kg CP diet and 1.41 in the corresponding capped diet and the capped 197.5 g/kg CP diet displayed promise.The growth performance this diet matched the positive control but outperformed the uncapped 197.5 g/kg CP diet by 10.4%(2,161 vs.1,958 g/bird;P=0.009)in weight gain,by 3.10%(3,492 vs.3,387 g/bird;P=0.019)in feed intake on the basis of pairwise comparisons and numerically improved FCR by 4.04%(1.616 vs.12684).However,the growth performance of birds offered the 180.0 and 162.5 g/kg CP dietary treatments was remarkably inferior,irrespective of dietary starch:protein ratios.This inferior growth performance was associated with poor feathering and even feather-pecking and significant linear relationships between feather scores and parameters of growth performance were observed.The amino acid profile of feathers was determined where cysteine,glutamic acid,glycine,proline and serine were dominant in a crude protein content of 931 g/kg.Presumably,the feathering issues observed were manifestations of amino acid inadequacies or imbalances in the more reduced-CP diets and consideration is given to the implications of these outcomes.
基金funding the sorghum steam-pelleting temperatures project
文摘The Liverpool Plains is a fertile agricultural region in New South Wales, Australia. Two sorghums from the2009 Liverpool Plains harvest, sorghums #3 and #5, were extensively characterised which included concentrations of kafirin and phenolic compounds plus rapid visco-analysis(RVA) starch pasting profiles. Diets based on these two sorghums were formulated to be iso-nitrogenous and iso-energetic and were offered to male Ross 308 broiler chicks from 7 to 28 days post–hatch as either intact pellets or reground mash following steam-pelleting at conditioning temperatures of either 65 or 97°C. Thus the feeding study consisted of a 2×2×2 factorial array of dietary treatments: two sorghum varieties, two feed forms and two conditioning temperatures. Each of the eight treatments was replicated six times with six birds per replicate cage.Assessed parameters included growth performance, nutrient utilisation, apparent starch and protein(N) digestibility coefficients and disappearance rates from the distal jejunum and distal ileum. Intact pellets supported higher(P <0.001) feed intakes and weight gains by 9.83 and 9.08%, respectively, than reground mash diets. Feed conversion ratios of broilers offered diets steam-conditioned at 97°C were 2.46% inferior(P <0.001) in comparison to 65°C diets and both apparent metabolizable energy(AME) and N-corrected AME(AMEn) were compromised. Broilers offered sorghum #3-based diets significantly(P <0.001) outperformed their sorghum #5 counterparts in terms of weight gain by 3.75%(1,334 versus 1,223 g/bird), FCR by 4.81%(1.524 versus 1.601), AME by 1.06 MJ(13.61 versus 12.55 MJ/kg), ME:GE ratio(ME:GE) by 4.81%(0.806 versus0.769) and AMEn by 1.03 MJ(12.38 versus 11.35 MJ/kg). The inferiority of sorghum #5 appeared to be associated with higher concentrations of kafirin(61.5 versus 50.7 g/kg) and conjugated phenolic acids,including ferulic acid(31.1 versus 25.6 mg/g). There were no significant differences in jejunal and ileal starch and protein(N) digestibility coefficients between the two sorghums. However, starch to protein(N) disappearance rate ratios from the distal jejunum were significantly(P <0.001) correlated with ME:GE and AME. The multiple linear regression equations indicated that energy utilisation was enhanced by coupling rapidly digestible protein with slowly digestible starch, which suggests that bilateral bioavailability of starch and protein is pivotal to efficient energy utilisation.
基金established and supported under the Australian Government's Cooperative Research Centres Programthe Poultry CRC for funding the project and support of Ms Ha Truong's PhD candidature
文摘The objective of the study was to investigate the possibility that tandem inclusions of a reducing agent and a protease may advantage chicken-meat production and to ascertain if the established benefits of including sodium metabisulphite in sorghum-based diets extend to wheat-based diets. The study comprised a 2 x 2 x 2 factorial array of treatments in which either nutritionally iso-nitrogenous and isoenergetic wheat-or sorghum-based diets, without and with sodium metabisulphite(2.75 g/kg), without and with protease(1,000 units/kg) were offered to broiler chickens from 7 to 28 days post-hatch. The effects of dietary treatments on growth performance, nutrient utilisation, protein(N) and starch digestibility coefficients and digestive dynamics were determined. A preliminary investigation into the effects of two treatments on concentrations of free amino acids and glucose in the portal circulation was conducted. There was significant feed grain by sodium metabisulphite interactions(P = 0.03 to 0.005) for parameters of nutrient utilisation(AME, ME:GE ratios, N retention, AMEn). For example, sodium metabisulphite inclusions in sorghum-based diets enhanced AME by 0.18 MJ(12.47 versus 12.29 MJ/kg) but depressed AME by 0.43 MJ(11.88 versus 12.31 MJ/kg) in wheat-based diets. There was a linear relationship between starch:protein disappearance rate ratios in the distal ileum with weight gain(r =-0.484; P = 0.0012) indicating that condensed ratios(or absorption of more protein relative to starch) advantaged growth performance. Concentrations of free amino acids in the portal circulation or the post-enteral availability of certain amino acids, including the branched-chain amino acids, methionine, phenylalanine and threonine, were significantly correlated to FCR. For example, threonine concentrations were negatively correlated to FCR(r =-0.773; P = 0.005). Finally, tandem inclusions of sodium metabisulphite and protease in sorghum-based diets may hold merit but it appears that the established 'energy sparing' effects of sodium metabisulphite inclusions in sorghum-based diets are not duplicated in wheat-based diets.
基金AgriFutures Chicken-meat for funding the’Formulating broiler diets based on protein and starch digestive dynamics’project(PRJ010216)and for their ongoing encouragement and supportfinancial support of Australian Government Research and Training Program International Scholarship for Mr Shemil Macelline awarded by Department of Education,Skills and Employment
文摘This study determined the variations in protein digestibilities and digestion rates in broiler chickens offered diets containing 7 different meat and bone meals(MBM).A total of 252 male Ross 308 broiler chickens were offered 7 atypical diets largely based on maize and MBM from 24 to 28 d post-hatch.Each experimental diet was offered to 6 replicates with 6 birds per replicate cage.Excreta were collected in their entirety from 25 to 27 d post-hatch and on 28 d post-hatch.Digesta samples were collected from the proximal jejunum,distal jejunum,proximal ileum and distal ileum.Apparent digestibilities of protein were determined in each segment and apparent digestibilities of amino acids were measured in the distal ileum.There were significant differences in apparent protein digestibility coefficients in the proximal jejunum(P=0.006),where broiler chickens offered the high ash beef meal(diet 7)generated the lowest protein digestibility in the proximal jejunum(0.318).Similarly,there were significant differences in apparent digestibility coefficients in the distal jejunum(P<0.001)and distal ileum(P<0.001)but not in the proximal ileum.More pronounced differences were found in the disappearance rate of protein and there were significant differences in all 4 segments of the small intestine(P<0.001).Broiler chickens offered the high ash beef meal had the lowest protein disappearance rate(P<0.001).No difference was observed in the predicted protein digestion rate(P=0.486)but chickens offered the high ash beef meal had the lowest potential digestible protein(0.662,P=0.034)whereas the highest potential digestible protein(0.739)was detected in diet 5(containing a beef meal).This study contributed to the establishment of a preliminary database to include digestion rates of starch and protein into practical diet formulation.
基金AgriFutures Chicken-meat for funding the'Optimising amino acid profiles and energy in reduced-protein diets'project(PRJ010520)。
文摘As lowering crude protein(CP)in poultry diets continues to minimize amino acid excess,it is important to understand the limiting order of amino acids and the impact of their deficiencies.Therefore,a pair of experiments were conducted to observe the effects of individual amino acid deletions on growth performance,carcass traits,and nutrient utilization.Both experiments involved 3 control diets based on wheat and soybean meal,including a 210.0 g/kg CP industry control(IC),186.7 g/kg CP positive control(PC)supplemented with feed-grade amino acids to match the IC amino acid profile,186.7 g/kg CP negative control(NC)with reducing N corrected apparent metabolizable energy(AMEN)by 0.5 MJ/kg and removing feed-grade amino acids beyond L-Lys-HCl,DL-Met,and L-Thr from PC.Ten deletion diets where the following supplemented amino acids were individually removed from the PC:Val,Ile,Leu,Trp,Arg,His,Phe t Tyr,glycine equivalence(Glyequi),Pro,and Energy(0.5 MJ/kg reduction in AMEN of the PC).All diets were formulated to contain similar concentrations of digestible Lys,total sulfur amino acid(TSAA)and Thr.Experimental diets were offered to broiler chickens from 15 to 22 d postehatch in a cage study(Exp.1)to gain digestibility and nutrient utilization data;whereas they were offered from 15 to 35 d post ehatch in a floor-pen study(Exp.2)to gain performance and carcass yield data.The removal of supplemented Val,Arg,and Ile resulted in reduction on broiler performance(P<0.05),and the removal of Val,Arg,Ile,and Glyequi negatively influenced carcass traits(P<0.05).Results from both experiments indicate that Val and Arg are co-limiting in wheat-soybean meal diets,but that Ile and Glyequi may potentially limit breast and thigh development.
文摘In a previous experiment,male Ross 308 broiler chickens were offered dietary treatments with 3 levels of crude protein(222,193,165 g/kg)and 3 feed grains(ground maize,ground wheat,whole wheat)from 7 to 35 d post-hatch.Maize-based diets supported superior growth performance in comparison to wheatbased diets.Uric acid concentrations in excreta were retrospectively determined and related to total nitrogen(N)excreta concentrations.Uric acid concentrations ranged from 28.5 to 69.4 mg/g and proportions of uric acid-N to total excreta-N ranged from 27.4%to 42.6%in broiler chickens offered the 3×3 factorial array of dietary treatments.Proportions of uric acid-N to total N in excreta in birds offered the165 g/kg CP,maize-based diet were significantly lower by 10.6 percentage units(27.4%versus 38.0%;P=0.00057)than their wheat-based counterparts.Total excreta analysed had been collected from 35 to37 d post-hatch when feed intakes and excreta outputs were monitored.There were linear relationships between proportions of uric acid-N to total N in excreta in birds offered the three 165 g/kg CP diets with weight gain(r=-0.587;P=0.010),feed intake(r=-0.526;P=0.025)and feed conversion ratios(r=0.635;P=0.005).The possibility that increasing uric acid-N proportions in excreta is indicative of excessive ammonia accumulations compromising growth performance is discussed.The mean proportion of dietary glycine involved in uric acid excretion was 49.2%across all dietary treatments but ranged from 25.0%to 80.9%.Thus,the appropriate amount of dietary glycine is variable and largely dependent on the volume of uric acid synthesised and excreted.
基金We would like to thank Ms Joy Gill,Ms Kylie Warr,Mr Duwei Chen and Mr Peter Bird of the Peanut Research Foundation within the University of Sydney for their invaluable technical assistance.Also,we would like to acknowledge the financial support provided by Australian Government Research and Training Program International Scholarship(RTP)for the PhD candidature of Mr Shemil Macelline.
文摘Graded quantities of 1.38,2.76 and 4.14 g/kg L-methionine were included in a control diet formulated to contain 3.07 g/kg digestible methionine.Each of the 4 dietary treatments was offered to 6 replicate cages(initially 8 birds per cage)from 1 to 21 d postehatch.The parameters assessed included growth performance,nutrient utilisation(apparent metabolisable energy[AME],AME:GE ratios,N retention,Ncorrected apparent metabolisable energy[AMEn]),apparent digestibility coefficients and disappearance rates of amino acids in the distal ileum.They also included free amino concentrations in systemic plasma(brachial vein)at 20 d postehatch and in hepatic tissue at 14 and 21 d postehatch.Graded L-methionine inclusions quadratically influenced weight gain(r=0.688;P=0.001)and FCR(r=0.780;P<0.001).It may be deduced from the quadratic regressions that 3.43 g/kg L-methionine supported maximum weight gain of 1,036 g/kg and 3.50 g/kg L-methionine minimum FCR of 1.193,from 1 to 21 d postehatch.The control diet contained specified levels of 3.07 g/kg digestible methionine and 13.0 g/kg digestible lysine.Thus,an inclusion of 3.465 g/kg L-methionine corresponded to a total of 6.535 g/kg methionine or a methionine-to-lysine ratio of 50.3,which is higher than standard recommendations.The implications of this and other outcomes of the present study are reported and discussed.
文摘Phototropins （phot1 and phot2） are blue-light receptor kinases controlling a range of responses that optimize the photosynthetic efficiency of plants. Light sensing is mediated by two flavin-binding motifs, known as LOVl and LOV2, located within the N-terminal region of the protein. Photoexcitation via LOV2 leads to activation of the C-terminal kinase domain and consequently receptor autophosphorylation. However, knowledge of the in-vivo phosphorylation sites for Arabidopsis phototropins is lacking and has impeded progress in elucidating the functional significance of receptor phos- phorylation. We have purified photl from Arabidopsis and identified the in-vivo sites of receptor phosphorylation by liquid chromatography tandem mass spectrometry. Arabidopsis-derived photl binds flavin mononucleotide as chromophore and is phosphorylated at four major sites located upstream of LOV2 （Ser^58, Ser^85, Ser^350, and Ser^410）, three of which are induced by blue light. Nevertheless, structure-function analysis indicates that the biological activity of photl can be attributed to a modular unit comprising the LOV2-kinase region of the protein. Thus, peptide regions upstream of LOV2, including the sites of receptor phosphorylation identified here, do not appear to be important for receptor signaling. By contrast, these regions may be necessary for maximizing stomatal performance and possibly light-induced relocalization of photl.
文摘Rice (Oryza sativa)is the primary staple food source for more than half of the world's population.Proteins are active macromolecules and central to understanding biological molecular processes. Hence,it is necessary to study all protein forms of plant genes so that their biological functions and roles in regulating important traits such as yield,quality,and responses to environmental stresses can be determined.
