Improving protein quality and grain yield traits coordinately is an important goal for crop breeding.To date,many protein-quality or grain-yield regulation genes have been identified.However,the genetic strategies int...Improving protein quality and grain yield traits coordinately is an important goal for crop breeding.To date,many protein-quality or grain-yield regulation genes have been identified.However,the genetic strategies integrating these genes in good-protein-quality and high-yield crop breeding practice are far from established.Here,we characterized the functions of the MADS domain-containing protein Zm MADS8 and Zea mays G protein gamma subunit 1(Zm GG1)in regulating protein quality and grain yield of maize.Zm MADS8 positively regulates zein protein accumulation and negatively regulates nonzein protein and lysine levels in kernels by interacting with Zm MADS47 to promote the transcriptional activation of Opaque2.Additionally,Zm MADS8 regulates starch content of kernels by targeting genes involved in starch biosynthesis.Zm GG1,a putative interactor of Zm MADS8,negatively regulates kernel number with a trade-off effect on kernel starch accumulation.The mads8;zmgg1 double mutant improved protein quality by attenuating zein biosynthesis and increasing essential lysine level,and increased grain yield by increasing kernel number,compensating for decreased starch biosynthesis.Our findings revealed the biological function of Zm MADS8 and Zm GG1 in regulating protein quality and yield related traits and suggested a genetic strategy by direct editing of Zm MADS8 and Zm GG1 to improve grain yield and protein quality simultaneously.展开更多
[Objective]The aim is to perform prokaryotic expression of the glycoprotein gene of infectious hnematopoietic necrosis virus and polyclonal antibody preparation. [Methods]Glycoprotein gene( G) of infectious hematopoie...[Objective]The aim is to perform prokaryotic expression of the glycoprotein gene of infectious hnematopoietic necrosis virus and polyclonal antibody preparation. [Methods]Glycoprotein gene( G) of infectious hematopoietic tissue( IHNV) was synthesized,cloned to prokaryotic expression system pET-30a vector,yielding the recombinant plasmid pET-30a-IHNV-G. The yielded pET-30a-IHNV-G was transformed into E. coli strain BL21( DE3) plySs. [Results] SDSPAGE and Western blot results showed that protein G successfully expressed in E. coli at 37 ℃,1 mmol /L IPTG induction for 4 h. The molecular weight of fusion G protein was 57 KD. The polyclonal antibody was prepared by immunizing mice with the product of gel purification. ELISA analysis showed that the serum titer reached 1∶10 000. [Conclusion]The expressed G protein and the serum with polyclonal antibody obtained in this study provided the theoretical basis for the development of IHNV vaccine and detection of colloidal gold test strip.展开更多
Hippocampal neuronal loss causes cognitive dysfunction in Alzheimer’s disease.Adult hippocampal neurogenesis is reduced in patients with Alzheimer’s disease.Exercise stimulates adult hippocampal neurogenesis in rode...Hippocampal neuronal loss causes cognitive dysfunction in Alzheimer’s disease.Adult hippocampal neurogenesis is reduced in patients with Alzheimer’s disease.Exercise stimulates adult hippocampal neurogenesis in rodents and improves memory and slows cognitive decline in patients with Alzheimer’s disease.However,the molecular pathways for exercise-induced adult hippocampal neurogenesis and improved cognition in Alzheimer’s disease are poorly understood.Recently,regulator of G protein signaling 6(RGS6)was identified as the mediator of voluntary running-induced adult hippocampal neurogenesis in mice.Here,we generated novel RGS6fl/fl;APP_(SWE) mice and used retroviral approaches to examine the impact of RGS6 deletion from dentate gyrus neuronal progenitor cells on voluntary running-induced adult hippocampal neurogenesis and cognition in an amyloid-based Alzheimer’s disease mouse model.We found that voluntary running in APP_(SWE) mice restored their hippocampal cognitive impairments to that of control mice.This cognitive rescue was abolished by RGS6 deletion in dentate gyrus neuronal progenitor cells,which also abolished running-mediated increases in adult hippocampal neurogenesis.Adult hippocampal neurogenesis was reduced in sedentary APP_(SWE) mice versus control mice,with basal adult hippocampal neurogenesis reduced by RGS6 deletion in dentate gyrus neural precursor cells.RGS6 was expressed in neurons within the dentate gyrus of patients with Alzheimer’s disease with significant loss of these RGS6-expressing neurons.Thus,RGS6 mediated voluntary running-induced rescue of impaired cognition and adult hippocampal neurogenesis in APP_(SWE) mice,identifying RGS6 in dentate gyrus neural precursor cells as a possible therapeutic target in Alzheimer’s disease.展开更多
BACKGROUND Regulator of G protein signaling(RGS)proteins participate in tumor formation and metastasis by acting on theα-subunit of heterotrimeric G proteins.The speci-fic effect of RGS,particularly RGS4,on the progr...BACKGROUND Regulator of G protein signaling(RGS)proteins participate in tumor formation and metastasis by acting on theα-subunit of heterotrimeric G proteins.The speci-fic effect of RGS,particularly RGS4,on the progression of gastric cancer(GC)is not yet clear.AIM To explore the role and underlying mechanisms of action of RGS4 in GC develop-ment.METHODS The prognostic significance of RGS4 in GC was analyzed using bioinformatics based public databases and verified by immunohistochemistry and quantitative polymerase chain reaction in 90 patients with GC.Function assays were employed to assess the carcinogenic impact of RGS4,and the mechanism of its possible influence was detected by western blot analysis.A nude mouse xenograft model was established to study the effects of RGS4 on GC growth in vitro.RESULTS RGS4 was highly expressed in GC tissues compared with matched adjacent normal tissues.Elevated RGS4 expression was correlated with increased tumor-node-metastasis stage,increased tumor grade as well as poorer overall survival in patients with GC.Cell experiments demonstrated that RGS4 knockdown suppressed GC cell proliferation,migration and invasion.Similarly,xenograft experiments confirmed that RGS4 silencing significantly inhibited tumor growth.Moreover,RGS4 knockdown resulted in reduced phosphorylation levels of focal adhesion kinase,phosphatidyl-inositol-3-kinase,and protein kinase B,decreased vimentin and N-cadherin,and elevated E-cadherin.CONCLUSION High RGS4 expression in GC indicates a worse prognosis and RGS4 is a prognostic marker.RGS4 influences tumor progression via the focal adhesion kinase/phosphatidyl-inositol-3-kinase/protein kinase B pathway and epithelial-mesenchymal transition.展开更多
Osteoarthritis(OA)is a prevalent degenerative joint disorder marked by chronic pain,inflammation,and cartilage loss,with current treatments limited to symptom relief.G protein-coupled receptors(GPCRs)play a pivotal ro...Osteoarthritis(OA)is a prevalent degenerative joint disorder marked by chronic pain,inflammation,and cartilage loss,with current treatments limited to symptom relief.G protein-coupled receptors(GPCRs)play a pivotal role in OA progression by regulating inflammation,chondrocyte survival,and matrix homeostasis.However,their multifaceted signaling,via G proteins orβ-arrestins,poses challenges for precise therapeutic targeting.Biased agonism,where ligands selectively activate specific GPCR pathways,emerges as a promising approach to optimize efficacy and reduce side effects.This review examines biased signaling in OAassociated GPCRs,including cannabinoid receptors(CB1,CB2),chemokine receptors(CCR2,CXCR4),protease-activated receptors(PAR-2),adenosine receptors(A1R,A2AR,A2BR,A3R),melanocortin receptors(MC1R,MC3R),bradykinin receptors(B2R),prostaglandin E2 receptors(EP-2,EP-4),and calcium-sensing receptors(CaSR).We analyze ligands in clinical trials and explore natural products from Traditional Chinese Medicine as potential biased agonists.These compounds,with diverse structures and bioactivities,offer novel therapeutic avenues.By harnessing biased agonism,this review underscores the potential for developing targeted,safer OA therapies that address its complex pathology,bridging molecular insights with clinical translation.展开更多
Heterotrimeric G protein serves as a central hub in plant signal transduction,playing a pivotal role in integrating endogenous developmental signals and external environmental cues.While significant advances have been...Heterotrimeric G protein serves as a central hub in plant signal transduction,playing a pivotal role in integrating endogenous developmental signals and external environmental cues.While significant advances have been made in understanding G protein signaling mechanisms in model plants such as Arabidopsis and major crops like rice and maize,the precise regulatory roles in growth,development,and adaptation in horticultural crops are still poorly understood.In this review,we systematically summarize recent advances in uncovering both conserved and species-specific regulatory mechanisms of G protein signaling across diverse plant species.We also highlight key discoveries on the crosstalk between G protein-mediated pathways and other signaling cascades,such as hormone signaling,transcriptional regulation,and stress response networks.Finally,we discuss the potential applications of G protein signaling research in future crop improvement,offering new perspectives for advancing sustainable horticultural production.展开更多
GNAO1-associated disorder is a rare disease and an example of developmental and epileptic encephalopathies.Caused by ca.150 different dominant missense mutations in the gene encoding the major neuronal G protein Gao,i...GNAO1-associated disorder is a rare disease and an example of developmental and epileptic encephalopathies.Caused by ca.150 different dominant missense mutations in the gene encoding the major neuronal G protein Gao,it spans a wide range of neurological clinical manifestations,that may include epileptic seizures,motor dysfunctions,developmental and intellectual delay,and other symptoms(Sáez González et al.,2023).展开更多
Objective: To observe the effect of electroacupuncture (EA) on gene expr ession o f α subunit of Go-protein in the brain of rats with hypertensive cerebral hem or rage and study its underlying mechanisms of EA in ame...Objective: To observe the effect of electroacupuncture (EA) on gene expr ession o f α subunit of Go-protein in the brain of rats with hypertensive cerebral hem or rage and study its underlying mechanisms of EA in ameliorating cerebral hemorrag e. Methods: A total of 130 SD rats were randomly divided into nor mal control gro up (n=10), sham operation group (n=40), model group (n=40) and EA group (n=40). The latter 3 groups were further divided into 6 h, 24 h, 48 h and 72 h (tim e course s) subgroups, with 10 rats being in each subgroup. The hypertensive cerebral hem orrage model was induced by injecting 1 μL of collagenase (0.5 U/μL collagena se Type Ⅶ) and heparin (7 U/μL) into the caudate nucleus in rats with renovascul ar hypertension (by clipping the bilateral renal arteries). The gene expression of α subunit of Go-protein in the hippocampus tissue of rats was detected with No rthern blotting hybridization analysis. EA (continuous waves, 120 pulses/min in frequency, 1 mA in intensity and duration of 30 min) was applied to "Shuigou" (水沟 GV 26), bilateral "Neiguan"(内关 PC 6) and bilateral "Housanli"(Zusanl i, 足三里 ST 36). Results: The gene expression of α subunit of Go-protein in th e hippocampus tis sue of the rats was obviously downregulated in hypertensive cerebral hemorrage m odel group and significantly upregulated after EA treatment wit h the extension of time. Conlusion: EA may relieve cerebral hemorr age by regulating the gene transcription of α subunit of Go-protein and incre asing the expression of Go-α protein. This may be one of the molecular mechani sm s of EA in improving hypertensive cerebral hemorrhage.展开更多
Heterotrimeric guanine nucleotide-binding protein （G protein） signaling is an evolutionarily conserved mechanism in diverse eukaryotic organisms. In plants, the repertoire of the heterotrimeric G protein complex, wh...Heterotrimeric guanine nucleotide-binding protein （G protein） signaling is an evolutionarily conserved mechanism in diverse eukaryotic organisms. In plants, the repertoire of the heterotrimeric G protein complex, which is composed of the Ga, Gβ, and Gy subunits, is much simpler than that in metazoans, and the identity of typical G protein-coupled receptors （GPCRs） together with their ligands still remains unclear. Comparative phenotypic analysis in Arabidopsis and rice plants using gain- and loss-of-function mutants of G protein components revealed that heterotrimeric G protein signaling plays important roles in a wide variety of plant growth and developmental processes. Grain yield is a complex trait determined by quantitative trait loci （QTL） and is influenced by soil nitrogen availability and environmental changes. Recent studies have shown that the manipulation of two non-canonical Gy subunits, GS3 （GRAIN SIZE 3） and DEP1 （DENSE AND ERECT PANICLE 1）, represents new strategies to simultaneously increase grain yield and nitrogen use efficiency in rice. This review discusses the latest advances in our understanding of the heterotrimeric G protein signal transduction pathway and its application in improving yield and stress tolerance in crops.展开更多
Heterotrimeric G proteins are known to function as messengers in numerous signal transduction pathways.The nullmutation of RGA(rice heterotrimeric G protein α subunit),which encodes the α subunit of heterotrimeric G...Heterotrimeric G proteins are known to function as messengers in numerous signal transduction pathways.The nullmutation of RGA(rice heterotrimeric G protein α subunit),which encodes the α subunit of heterotrimeric G proteinin rice,causes severe dwarfism and reduced responsiveness to gibberellic acid in rice.However,less is known aboutheterotrimeric G protein in brassinosteroid(BR)signaling,one of the well-understood phytohormone pathways.In thepresent study,we used root elongation inhibition assay,lamina inclination assay and coleoptile elongation analysis todemonstrated reduced sensitivity of dl mutant plants(caused by the null mutation of RGA)to 24-epibrassinolide(24-epiBL),which belongs to brassinosteroids and plays a wide variety of roles in plant growth and development.Moreover,RGA transcript level was decreased in 24-epiBL-treated seedlings in a dose-dependent manner.Our results show thatRGA is involved in rice brassinosteroid response,which may be beneficial to elucidate the molecular mechanisms of Gprotein signaling and provide a novel perspective to understand BR signaling in higher plants.展开更多
The heterotrimeric guanine nucleotide-binding protein （G-protein） has been demonstrated to mediate various signaling pathways in plants. However, its role in phytochrome A （phyA） signaling remains elusive. In this...The heterotrimeric guanine nucleotide-binding protein （G-protein） has been demonstrated to mediate various signaling pathways in plants. However, its role in phytochrome A （phyA） signaling remains elusive. In this study, we discover a new phyA-mediated phenotype designated far-red irradiation （FR） preconditioned cell death, which occurs only in the hypocotyls of FR-grown seedlings following exposure to white light （WL）. The cell death is mitigated in the Gα mutant gpal but aggravated in the Gβ mutant agbl in comparison with the wild type （WT）, indicative of antagonistic roles of GPA1 and AGBI in the phyA-mediated cell-death pathway. Further investigation indicates that FR-induced accumulation of nonphotoconvertible protochlorophyllide （Pchlide^633）, which generates reactive oxygen species （ROS） on exposure to WL, is required for FR-preconditioned cell death. Moreover, ROS is mainly detected in chloroplasts using the fluorescent probe. Interestingly, the application of H2O2 to dark-grown seedlings results in a phenotype similar to FR-preconditioned cell death. This reveals that ROS is a critical mediator for the ceil death. In addition, we observe that agb1 is more sensitive to H2O2 than WT seedlings, indicating that the G-protein may also modify the sensitivity of the seedlings to ROS stress. Taking these results together, we infer that the G-protein may be involved in the phyA signaling pathway to regulate FR-preconditioned cell death ofArabidopsis hypocotyls. A possible mechanism underlying the involvement of the G-protein in phyA signaling is discussed in this study.展开更多
基金supported by the Biological Breeding-National Science and Technology Major Project(2023ZD0406804,2023ZD0402701)Major Project of Hubei Hongshan Laboratory(2022hszd019)First-Class Discipline Construction Funds of the College of Plant Science and Technology at Huazhong Agricultural University(2022ZK PY002)。
文摘Improving protein quality and grain yield traits coordinately is an important goal for crop breeding.To date,many protein-quality or grain-yield regulation genes have been identified.However,the genetic strategies integrating these genes in good-protein-quality and high-yield crop breeding practice are far from established.Here,we characterized the functions of the MADS domain-containing protein Zm MADS8 and Zea mays G protein gamma subunit 1(Zm GG1)in regulating protein quality and grain yield of maize.Zm MADS8 positively regulates zein protein accumulation and negatively regulates nonzein protein and lysine levels in kernels by interacting with Zm MADS47 to promote the transcriptional activation of Opaque2.Additionally,Zm MADS8 regulates starch content of kernels by targeting genes involved in starch biosynthesis.Zm GG1,a putative interactor of Zm MADS8,negatively regulates kernel number with a trade-off effect on kernel starch accumulation.The mads8;zmgg1 double mutant improved protein quality by attenuating zein biosynthesis and increasing essential lysine level,and increased grain yield by increasing kernel number,compensating for decreased starch biosynthesis.Our findings revealed the biological function of Zm MADS8 and Zm GG1 in regulating protein quality and yield related traits and suggested a genetic strategy by direct editing of Zm MADS8 and Zm GG1 to improve grain yield and protein quality simultaneously.
文摘[Objective]The aim is to perform prokaryotic expression of the glycoprotein gene of infectious hnematopoietic necrosis virus and polyclonal antibody preparation. [Methods]Glycoprotein gene( G) of infectious hematopoietic tissue( IHNV) was synthesized,cloned to prokaryotic expression system pET-30a vector,yielding the recombinant plasmid pET-30a-IHNV-G. The yielded pET-30a-IHNV-G was transformed into E. coli strain BL21( DE3) plySs. [Results] SDSPAGE and Western blot results showed that protein G successfully expressed in E. coli at 37 ℃,1 mmol /L IPTG induction for 4 h. The molecular weight of fusion G protein was 57 KD. The polyclonal antibody was prepared by immunizing mice with the product of gel purification. ELISA analysis showed that the serum titer reached 1∶10 000. [Conclusion]The expressed G protein and the serum with polyclonal antibody obtained in this study provided the theoretical basis for the development of IHNV vaccine and detection of colloidal gold test strip.
基金supported by the National Institutes of Health,Nos.AA025919,AA025919-03S1,and AA025919-05S1(all to RAF).
文摘Hippocampal neuronal loss causes cognitive dysfunction in Alzheimer’s disease.Adult hippocampal neurogenesis is reduced in patients with Alzheimer’s disease.Exercise stimulates adult hippocampal neurogenesis in rodents and improves memory and slows cognitive decline in patients with Alzheimer’s disease.However,the molecular pathways for exercise-induced adult hippocampal neurogenesis and improved cognition in Alzheimer’s disease are poorly understood.Recently,regulator of G protein signaling 6(RGS6)was identified as the mediator of voluntary running-induced adult hippocampal neurogenesis in mice.Here,we generated novel RGS6fl/fl;APP_(SWE) mice and used retroviral approaches to examine the impact of RGS6 deletion from dentate gyrus neuronal progenitor cells on voluntary running-induced adult hippocampal neurogenesis and cognition in an amyloid-based Alzheimer’s disease mouse model.We found that voluntary running in APP_(SWE) mice restored their hippocampal cognitive impairments to that of control mice.This cognitive rescue was abolished by RGS6 deletion in dentate gyrus neuronal progenitor cells,which also abolished running-mediated increases in adult hippocampal neurogenesis.Adult hippocampal neurogenesis was reduced in sedentary APP_(SWE) mice versus control mice,with basal adult hippocampal neurogenesis reduced by RGS6 deletion in dentate gyrus neural precursor cells.RGS6 was expressed in neurons within the dentate gyrus of patients with Alzheimer’s disease with significant loss of these RGS6-expressing neurons.Thus,RGS6 mediated voluntary running-induced rescue of impaired cognition and adult hippocampal neurogenesis in APP_(SWE) mice,identifying RGS6 in dentate gyrus neural precursor cells as a possible therapeutic target in Alzheimer’s disease.
基金Supported by the Fundamental Research Program of Shanxi Province,No.202203021222418Research Program of Shanxi Provincial Health Commission,No.2023061+2 种基金Fundamental Research Cooperation Program of Beijing-Tianjin-Hebei Region of Natural Science Foundation of Tianjin,No.22JCZXJC00140Tianjin Major Science and Technology Project,No.21ZXJBSY00110Tianjin Health and Science and Technology Project,No.TJWJ2024ZK001.
文摘BACKGROUND Regulator of G protein signaling(RGS)proteins participate in tumor formation and metastasis by acting on theα-subunit of heterotrimeric G proteins.The speci-fic effect of RGS,particularly RGS4,on the progression of gastric cancer(GC)is not yet clear.AIM To explore the role and underlying mechanisms of action of RGS4 in GC develop-ment.METHODS The prognostic significance of RGS4 in GC was analyzed using bioinformatics based public databases and verified by immunohistochemistry and quantitative polymerase chain reaction in 90 patients with GC.Function assays were employed to assess the carcinogenic impact of RGS4,and the mechanism of its possible influence was detected by western blot analysis.A nude mouse xenograft model was established to study the effects of RGS4 on GC growth in vitro.RESULTS RGS4 was highly expressed in GC tissues compared with matched adjacent normal tissues.Elevated RGS4 expression was correlated with increased tumor-node-metastasis stage,increased tumor grade as well as poorer overall survival in patients with GC.Cell experiments demonstrated that RGS4 knockdown suppressed GC cell proliferation,migration and invasion.Similarly,xenograft experiments confirmed that RGS4 silencing significantly inhibited tumor growth.Moreover,RGS4 knockdown resulted in reduced phosphorylation levels of focal adhesion kinase,phosphatidyl-inositol-3-kinase,and protein kinase B,decreased vimentin and N-cadherin,and elevated E-cadherin.CONCLUSION High RGS4 expression in GC indicates a worse prognosis and RGS4 is a prognostic marker.RGS4 influences tumor progression via the focal adhesion kinase/phosphatidyl-inositol-3-kinase/protein kinase B pathway and epithelial-mesenchymal transition.
基金supported by the National Key R&D Program of the Ministry of Science and Technology(2023YFC2509900)National Natural Science Foundation of China(82374106)+3 种基金National Natural Science Foundation of China(U22A20371)the Basic and Applied Basic Research Fund of Guangdong Province(2021B1515120061)the Shenzhen Science and Technology Innovation Committee(JCYJ20210324102006017)SZ-HK Joint Laboratory for Innovative Biomaterials under CAS-HK Joint Laboratories(2024-2028).
文摘Osteoarthritis(OA)is a prevalent degenerative joint disorder marked by chronic pain,inflammation,and cartilage loss,with current treatments limited to symptom relief.G protein-coupled receptors(GPCRs)play a pivotal role in OA progression by regulating inflammation,chondrocyte survival,and matrix homeostasis.However,their multifaceted signaling,via G proteins orβ-arrestins,poses challenges for precise therapeutic targeting.Biased agonism,where ligands selectively activate specific GPCR pathways,emerges as a promising approach to optimize efficacy and reduce side effects.This review examines biased signaling in OAassociated GPCRs,including cannabinoid receptors(CB1,CB2),chemokine receptors(CCR2,CXCR4),protease-activated receptors(PAR-2),adenosine receptors(A1R,A2AR,A2BR,A3R),melanocortin receptors(MC1R,MC3R),bradykinin receptors(B2R),prostaglandin E2 receptors(EP-2,EP-4),and calcium-sensing receptors(CaSR).We analyze ligands in clinical trials and explore natural products from Traditional Chinese Medicine as potential biased agonists.These compounds,with diverse structures and bioactivities,offer novel therapeutic avenues.By harnessing biased agonism,this review underscores the potential for developing targeted,safer OA therapies that address its complex pathology,bridging molecular insights with clinical translation.
基金supported by the National Natural Science Foundation of China(Grant Nos.32172650,32430092)the Starry Night Science Fund of Zhejiang University Shanghai Institute for Advanced Study(Grant No.SN-ZJU-SIAS-0011)+1 种基金the Fundamental Research Funds for the Central Universities of China(Grant No.226-2024-00119)the Innovative Development of Horticulture Discipline of Zhejiang University(Grant No.B231220.0005-25).
文摘Heterotrimeric G protein serves as a central hub in plant signal transduction,playing a pivotal role in integrating endogenous developmental signals and external environmental cues.While significant advances have been made in understanding G protein signaling mechanisms in model plants such as Arabidopsis and major crops like rice and maize,the precise regulatory roles in growth,development,and adaptation in horticultural crops are still poorly understood.In this review,we systematically summarize recent advances in uncovering both conserved and species-specific regulatory mechanisms of G protein signaling across diverse plant species.We also highlight key discoveries on the crosstalk between G protein-mediated pathways and other signaling cascades,such as hormone signaling,transcriptional regulation,and stress response networks.Finally,we discuss the potential applications of G protein signaling research in future crop improvement,offering new perspectives for advancing sustainable horticultural production.
文摘GNAO1-associated disorder is a rare disease and an example of developmental and epileptic encephalopathies.Caused by ca.150 different dominant missense mutations in the gene encoding the major neuronal G protein Gao,it spans a wide range of neurological clinical manifestations,that may include epileptic seizures,motor dysfunctions,developmental and intellectual delay,and other symptoms(Sáez González et al.,2023).
文摘Objective: To observe the effect of electroacupuncture (EA) on gene expr ession o f α subunit of Go-protein in the brain of rats with hypertensive cerebral hem or rage and study its underlying mechanisms of EA in ameliorating cerebral hemorrag e. Methods: A total of 130 SD rats were randomly divided into nor mal control gro up (n=10), sham operation group (n=40), model group (n=40) and EA group (n=40). The latter 3 groups were further divided into 6 h, 24 h, 48 h and 72 h (tim e course s) subgroups, with 10 rats being in each subgroup. The hypertensive cerebral hem orrage model was induced by injecting 1 μL of collagenase (0.5 U/μL collagena se Type Ⅶ) and heparin (7 U/μL) into the caudate nucleus in rats with renovascul ar hypertension (by clipping the bilateral renal arteries). The gene expression of α subunit of Go-protein in the hippocampus tissue of rats was detected with No rthern blotting hybridization analysis. EA (continuous waves, 120 pulses/min in frequency, 1 mA in intensity and duration of 30 min) was applied to "Shuigou" (水沟 GV 26), bilateral "Neiguan"(内关 PC 6) and bilateral "Housanli"(Zusanl i, 足三里 ST 36). Results: The gene expression of α subunit of Go-protein in th e hippocampus tis sue of the rats was obviously downregulated in hypertensive cerebral hemorrage m odel group and significantly upregulated after EA treatment wit h the extension of time. Conlusion: EA may relieve cerebral hemorr age by regulating the gene transcription of α subunit of Go-protein and incre asing the expression of Go-α protein. This may be one of the molecular mechani sm s of EA in improving hypertensive cerebral hemorrhage.
基金supported by grants from the National Natural Science Foundation of China(Nos.31401353,31301286,31430062 and 31371587)
文摘Heterotrimeric guanine nucleotide-binding protein （G protein） signaling is an evolutionarily conserved mechanism in diverse eukaryotic organisms. In plants, the repertoire of the heterotrimeric G protein complex, which is composed of the Ga, Gβ, and Gy subunits, is much simpler than that in metazoans, and the identity of typical G protein-coupled receptors （GPCRs） together with their ligands still remains unclear. Comparative phenotypic analysis in Arabidopsis and rice plants using gain- and loss-of-function mutants of G protein components revealed that heterotrimeric G protein signaling plays important roles in a wide variety of plant growth and developmental processes. Grain yield is a complex trait determined by quantitative trait loci （QTL） and is influenced by soil nitrogen availability and environmental changes. Recent studies have shown that the manipulation of two non-canonical Gy subunits, GS3 （GRAIN SIZE 3） and DEP1 （DENSE AND ERECT PANICLE 1）, represents new strategies to simultaneously increase grain yield and nitrogen use efficiency in rice. This review discusses the latest advances in our understanding of the heterotrimeric G protein signal transduction pathway and its application in improving yield and stress tolerance in crops.
基金This project was supported by the Major State Basic Research Program of China （2005CB 120806）, National Natural Science Foundation of China for Distinguished Young Scholars （30525026） and the State Transgenic Plant Project （JY04-A-01）
文摘Heterotrimeric G proteins are known to function as messengers in numerous signal transduction pathways.The nullmutation of RGA(rice heterotrimeric G protein α subunit),which encodes the α subunit of heterotrimeric G proteinin rice,causes severe dwarfism and reduced responsiveness to gibberellic acid in rice.However,less is known aboutheterotrimeric G protein in brassinosteroid(BR)signaling,one of the well-understood phytohormone pathways.In thepresent study,we used root elongation inhibition assay,lamina inclination assay and coleoptile elongation analysis todemonstrated reduced sensitivity of dl mutant plants(caused by the null mutation of RGA)to 24-epibrassinolide(24-epiBL),which belongs to brassinosteroids and plays a wide variety of roles in plant growth and development.Moreover,RGA transcript level was decreased in 24-epiBL-treated seedlings in a dose-dependent manner.Our results show thatRGA is involved in rice brassinosteroid response,which may be beneficial to elucidate the molecular mechanisms of Gprotein signaling and provide a novel perspective to understand BR signaling in higher plants.
文摘The heterotrimeric guanine nucleotide-binding protein （G-protein） has been demonstrated to mediate various signaling pathways in plants. However, its role in phytochrome A （phyA） signaling remains elusive. In this study, we discover a new phyA-mediated phenotype designated far-red irradiation （FR） preconditioned cell death, which occurs only in the hypocotyls of FR-grown seedlings following exposure to white light （WL）. The cell death is mitigated in the Gα mutant gpal but aggravated in the Gβ mutant agbl in comparison with the wild type （WT）, indicative of antagonistic roles of GPA1 and AGBI in the phyA-mediated cell-death pathway. Further investigation indicates that FR-induced accumulation of nonphotoconvertible protochlorophyllide （Pchlide^633）, which generates reactive oxygen species （ROS） on exposure to WL, is required for FR-preconditioned cell death. Moreover, ROS is mainly detected in chloroplasts using the fluorescent probe. Interestingly, the application of H2O2 to dark-grown seedlings results in a phenotype similar to FR-preconditioned cell death. This reveals that ROS is a critical mediator for the ceil death. In addition, we observe that agb1 is more sensitive to H2O2 than WT seedlings, indicating that the G-protein may also modify the sensitivity of the seedlings to ROS stress. Taking these results together, we infer that the G-protein may be involved in the phyA signaling pathway to regulate FR-preconditioned cell death ofArabidopsis hypocotyls. A possible mechanism underlying the involvement of the G-protein in phyA signaling is discussed in this study.
