Many eukaryotic genes are members of multi-gene families due to gene duplications, which generate new copies that allow functional divergence. However, the relationship between
A fundamental goal in cellular signaling is to understand allosteric communication, the process by which sig-nals originating at one site in a protein propagate reliably to affect distant functional sites. The general...A fundamental goal in cellular signaling is to understand allosteric communication, the process by which sig-nals originating at one site in a protein propagate reliably to affect distant functional sites. The general principles of protein structure that underlie this process remain unknown. Statistical coupling analysis （SCA） is a statistical technique that uses evolutionary data of a protein family to measure correlation between distant functional sites and suggests allosteric communication. In proteins, very distant and small interactions between collections of amino acids provide the communication which can be important for signaling process. In this paper, we present the SCA of protein alignment of the esterase family （pfam ID： PF00756） containing the sequence of antigen 85C secreted by Mycobacterium tuberculosis to identify a subset of interacting residues. Clustering analysis of the pairwise correlation highlighted seven important residue positions in the esterase family alignments. These resi-dues were then mapped on the crystal structure of antigen 85C （PDB ID： 1DQZ）. The mapping revealed corre-lation between 3 distant residues （Asp38, Leu123 and Met125） and suggests allosteric communication between them. This information can be used for a new drug against this fatal disease.展开更多
Using HCl to activate the diapause eggs is a traditional technique of artificial hatching applied in silkworm egg production. Its mechanism has not yet been clarified. This experiment explored the effect of HCl on the...Using HCl to activate the diapause eggs is a traditional technique of artificial hatching applied in silkworm egg production. Its mechanism has not yet been clarified. This experiment explored the effect of HCl on the termination of diapause of silkworm eggs cold-stored for 45 days from the point of proteomes. Two-dimensional electrophoresis techniques and ESI- MS-MS were used to compare and analyze the variation expression of difficult-dissolved-proteins of diapause eggs coldstored for 45 days before and after acid treatment. Through analysis on the two-dimensional electrophoretogram, there were 296 dots before acid treatment and 302 after the treatment, respectively. Amongst them 265 dots were matchable. The matchability reached 88.6%. There were 31 specific protein dots before acid treatment and 37 after acid treatment, respectively. ESI-MS-MS analysis was conducted for two specific protein-rich dots which disappeared after acid treatment. The results indicated that the sequence of No. 1 protein dot had 55 amino acids＇ peptide matched with those of chorion protein （Bombyx mori）. While the sequence of No. 2 protein dot had only 15 amino acids＇ peptide matched with those of heat shock protein hsp 19.9 （Bombyx mori）, and it was presumed to be an unknown protein. The difficult-dissolvedproteins of diapause eggs have variation expression after acid treatment. Some proteins before and after acid treatment are changed in MW.展开更多
Apoptosis proteins play an important role in the development and homeostasis of an organism. The elucidation of the subcellular locations and functions of these proteins is helpful for understanding the mechanism of p...Apoptosis proteins play an important role in the development and homeostasis of an organism. The elucidation of the subcellular locations and functions of these proteins is helpful for understanding the mechanism of programmed cell death. In this paper, the recurrent quantification analysis, Hilbert-Huang transform methods, the maximum relevance and minimum redundancy method and support vector machine are used to predict the subcellular location of apoptosis proteins. The validation of the jackknife test suggests that the proposed method can improve the prediction accuracy of the subcellular location of apoptosis proteins and its application may be promising in other fields.展开更多
Bordetella bronchiseptica is a Gram-negative pathogen that causes acute and chronic respiratory infection in a variety of animals. To identify useful antigen candidates for diagnosis and subunit vaccine of B. bronchis...Bordetella bronchiseptica is a Gram-negative pathogen that causes acute and chronic respiratory infection in a variety of animals. To identify useful antigen candidates for diagnosis and subunit vaccine of B. bronchiseptica, immunoproteomic analysis was adopted to analyse outer membrane proteins of it. The outer membrane proteins extracted from B. bronchiseptica were separated by two-dimensional gel electrophoresis and analyzed by Western blotting for their reactivity with the convalescent serum against two strains. Immunogenic proteins were identified by matrix-assisted laser desorption/ionization time of flight-mass spectrometry（MALDI-TOF-MS）, a total of 14 proteins are common immunoreactive proteins, of which 1 was known antigen and 13 were novel immunogenic proteins for B. bronchiseptica. Putative lipoprotein gene was cloned and recombinantly expressed. The recombinant protein induced high titer antibody, but showed low protective indices against challenges with HB（B. bronchiseptica strain isolated from a infected rabbit）. The mortality of mice was 80% compared to 100% of positive controls. The identification of these novel antigenic proteins is an important resource for further development of a new diagnostic test and vaccine for B. bronchiseptica.展开更多
The amino acid sequences of the NP, P, M, F, HN and L proteins of the paramyxovirus Tianjin strain were analyzed by using the bioinformatics methods. Phylogenetic analysis based on 6 structural proteins among the Tian...The amino acid sequences of the NP, P, M, F, HN and L proteins of the paramyxovirus Tianjin strain were analyzed by using the bioinformatics methods. Phylogenetic analysis based on 6 structural proteins among the Tianjin strain and 25 paramyxoviruses showed that the Tianjin strain belonged to the genus Respirovirus, in the subfamily Paramyxovirinae, and was most closely related to Sendai virus (SeV). Phylogenetic analysis with 14 known SeVs showed that Tianjin strain represented a new evolutionary lineage. Similarities comparisons indicated that Tianjin strain P protein was poorly conserved, sharing only 78.7% - 91.9% amino acid identity with the known SeVs, while the L protein was the most conserved, having 96.0% - 98.0% amino acid identity with the known SeVs. Alignments of amino acid sequences of 6 structural proteins clearly showed that Tianjin strain possessed many unique amino acid substitutions in their protein sequences, 15 in NP, 29 in P, 6 in M, 13 in F, 18 in HN, and 29 in L. These results revealed that Tianjin strain was most likely a new genotype of SeV. The presence of unique amino acid substitutions suggests that Tianjin strain maybe has a significant difference in biological, pathological, immunological, or epidemiological characteristics from the known SeVs.展开更多
Hypoxia preconditioning （HPC） is associated with many complicated pathophysiological and biochemical processes that integrated and regulated via molecular levels. HPC could protect cells, tissues, organs and systems...Hypoxia preconditioning （HPC） is associated with many complicated pathophysiological and biochemical processes that integrated and regulated via molecular levels. HPC could protect cells, tissues, organs and systems from hypoxia injury, but up to date, the molecular mechanism still remained unclear. The acute and repetitive hy- poxia preconditioning model was constructed and the related parameters were observed. The high-throughput mi- croarray analysis and multiple bioinformatics were used to explore the differentially expressed genes in HPC mice brain and the related gene network, pathways and biological processes related to HPC. The 2D-DIGE coupled with MALDI-TOF/TOF-MS was performed to identify these proteins that were differentially expressed during HPC. The UPLC-HRMS based metabolomics method was utilized to explore the key endogenous metabolites and metabolic pathways related to HPC. The results showed that （1） 1175 differentially expressed genes in HPC mice brain were identified. Fourteen of these genes were the related hub genes for HPC, including Cacna2dl, Grin2a, Npylr, Mef2c, Epha4, Rxfpl, Chrm3, Pdela, Atp2b4, Glral, Idil , Fgfl, Grin2b and Cda. The change trends of all the detected genes by RT-PCR were consistent with the data of gene chips. There were 113 significant functions up- regulated and 138 significant functions down-regulated in HPC mice. （2） About 2100 proteins were revealed via the gel imaging and spot detection. 66, 45 and 70 of proteins were found to have significantly difference between the control group and three times of HPC group, the control and six times of HPC, and the three times of HPC and six times of HPC group. （3）Some endogenous metabolites such as phenylalanine, valine, proline, leucine and glu- tamine were increased, while ereatine was decreased, both in HPC brain and heart; in addition, y-aminobutyric acid was markedly decreased in brain. The sphingolipid metabolic pathways were noticed due to the low p-value and high pathway impact. Especially, the sphingolipid compound sphingomyelin, ceramide, glucosyleeramide, galactosylceramide and laetosylceramide were mapping in this metabolic pathway. Interestingly, these sphingolipid metabolites with olefinic bond in the long fatty chain were up-regulated, while those sphingolipids without olefinic bond were down-regulated. The functions of these differentially expressed genes mainly involved the cellular proces- ses including MAPK pathway, ion transport, neurotransmitter transport and neuropeptide signal pathway. The pro- tein levels related the ATP synthesis and citric acid cycle decreased while the proteins with the glycolysis and oxy- gen-binding increased. Glutathione, GNBP-1 and GPD1L were related to preventing hypoxic damage. The results indicated that C24：l-Cers played a critical role in HPC and had potential in endogenous protective mechanism. The combinations of the system omies data of the different molecules were sufficient to give a further understanding of the molecular pathways affected by HPC. Our data provided an important insight to reveal the protection mechanism of HPC.展开更多
The influence of water temperature on protein composition in the reconstitution of milk powder was evaluated using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF MS）. 11 ion ...The influence of water temperature on protein composition in the reconstitution of milk powder was evaluated using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF MS）. 11 ion peaks in the matrix-assisted laser desorption/ionization （MALDI） spectra were examined to study the alteration of relative quantities of milk proteins when water at different temperature was employed in the reconstitution of milk powder. A discrepancy factor Dij was implemented to represent the degree of milk proteins＇ denaturation. Data obtained indicated that Dij value increased with rising water temperature, and thermal damage to milk proteins became evidently when the water temperature exceeded 60℃. The results confirmed that nutrient loss occurred when milk proteins denatured in water at high temperatures.展开更多
Chronic stress can induce hippocampus injury such as neuron loss and dendrite atrophy,but its mechanism and molecular basis remain unclear up to now.To understand the molecular mechanism on protein level and find the ...Chronic stress can induce hippocampus injury such as neuron loss and dendrite atrophy,but its mechanism and molecular basis remain unclear up to now.To understand the molecular mechanism on protein level and find the crucial proteins which correlated with chronic展开更多
Peptidoglycan recognition proteins（PGRPs） are a family of pattern recognition receptors（PRRs） of the immune system,which bind and hydrolyze bacterial peptidoglycan.Here,a long type PGRP（PGRP-L） was first cloned ...Peptidoglycan recognition proteins（PGRPs） are a family of pattern recognition receptors（PRRs） of the immune system,which bind and hydrolyze bacterial peptidoglycan.Here,a long type PGRP（PGRP-L） was first cloned in the lower vertebrate species Xenopus tropicalis（Xt）.The XtPGRP-L possessed a conserved genomic structure with five exons and four introns.The alignment and phylogenetic analysis indicated that XtPGRP-L might be a type of amidase-like PGRP.The 3-D model showed that XtPGRP-L possessed a conserved structure compared with the Drosophila PGRP-Lb.During embryonic development,XtPGRP-L was not expressed until the 72 h tadpole stage.In adult tissues,it was strongly expressed in the liver,lung,intestine,and stomach.Furthermore,after LPS stimulation,the expression of XtPGRP-L was up-regulated significantly in the liver,intestine and spleen,indicating that XtPGRP-L may play an important role in the innate immunity of Xenopus tropicalis.展开更多
Background Lung squamous cell carcinoma(LUSC)is a major subtype of non-small cell lung cancer with a high mortality rate.Identifying causal plasma proteins associated with LUSC could provide new insights into the path...Background Lung squamous cell carcinoma(LUSC)is a major subtype of non-small cell lung cancer with a high mortality rate.Identifying causal plasma proteins associated with LUSC could provide new insights into the pathophysiology of the disease and potential therapeutic targets.This study aimed to identify plasma proteins causally linked to LUSC risk using proteome-wide Mendelian randomization(MR)and colocalization analyses.Methods Proteome-wide MR analysis was conducted using data from the UK Biobank Pharma Proteomics Project and deCODE genetics.Summary-level data for LUSC were obtained from the ILCCO Consortium,the FinnGen study,and a separate GWAS study.A total of 1,046 shared protein quantitative trait loci(pQTLs)were analyzed.Sensitivity analyses included the HEIDI test for horizontal pleiotropy and colocalization analysis to validate the causal associations.Results MR analysis identified six plasma proteins associated with LUSC risk:HSPA1L,PCSK7,POLI,SPINK2,TCL1A,and VARS.HSPA1L(OR=0.47;95%CI:0.34–0.65;P=4.89×10^(–6)),SPINK2(OR=0.68;95%CI:0.58–0.80;P=3.17×10^(–6)),and VARS(OR=0.44;95%CI:0.31–0.63;P=5.94×10^(–6))were associated with a decreased risk of LUSC.Conversely,PCSK7(OR=1.37;95%CI:1.21–1.56;P=1.40×10^(–6)),POLI(OR=4.50;95%CI:2.25–9.00;P=2.13×10–5),and TCL1A(OR=1.72;95%CI:1.34–2.21;P=1.89×10–5)were associated with an increased risk.The SMR analysis and HEIDI test confirmed the robustness of these associations.HSPA1L,SPINK2,and VARS showed significant inverse associations,with strong colocalization evidence for TCL1A(PPH4=0.817).Conclusions This study identified six plasma proteins potentially causal for LUSC risk.HSPA1L,SPINK2,and VARS are associated with decreased risk,while PCSK7,POLI,and TCL1A are linked to increased risk.These findings provide new insights into LUSC pathogenesis and highlight potential targets for therapeutic intervention.展开更多
[ Objective] The study was to clone HN and F genes from GX1 strain of goose paramyxovirus and analyze their sequences. [ Method] According to the full nucleotide sequence of GPV-SF02 strain of goose paramyxovirus, two...[ Objective] The study was to clone HN and F genes from GX1 strain of goose paramyxovirus and analyze their sequences. [ Method] According to the full nucleotide sequence of GPV-SF02 strain of goose paramyxovirus, two pairs of pdmers were designed to amplify the HN and F genes from GX1 strain of goose paramyxovirus isolated from diseased goose in Guangxi Zhuang Autonomous Region; the amplified products were ligated into pMD18-T vector and sequenced. [ Result ] HN and F genes of this strain tested were 1 716 and 1 662 bp in full nucleotide length, respectively; both showed the homologues of about 97.3% with GPV- SF02 strain, of 80.3% -97.5% with strains LaSota, F48E9 and JS, of just 84.8% with Miyadera strain. [ Conclusion] The results show that isolated strain BX1 matches to virulent APMV-1 strain, belonging to genotype Ⅶ of APMV-1 strain.展开更多
OBJECTIVE To investigate the changes and values of the expression of α-tubulin and γ-tubulin in atypical ductal hyperplasia （ADH）, ductal carcinoma in situ （DCIS） and invasive ductal carcinoma （IDC） of the bre...OBJECTIVE To investigate the changes and values of the expression of α-tubulin and γ-tubulin in atypical ductal hyperplasia （ADH）, ductal carcinoma in situ （DCIS） and invasive ductal carcinoma （IDC） of the breast. The relationship between centrosome abnormalities and breast tumor development was further discussed. METHODS There were three groups including ADH, DCIS and IDC with 30 cases in each group. They were analyzed by immuno-fiuorescence quantity analysis. The expression levels of α-tubulin and γ-tubulin protein in these tissues were detected by flow cytometry immuno-fiuorescence analysis and compared with the results from normal tissues. Immunohistochemistry was also performed in this research. RESULTS The results showed significant differences of the average of the positive （FITC labeled） cells （P=0.000） among the four groups. The level of the IDC group was the highest, while normal breast tissue showed the lowest level. The results suggested that the expression levels of α-tubulin and γ-tubulin both increased as the grade of cellular proliferation and differentiation increased. The expressions showed significant differences among all the groups, except between the ADH and DCIS. There were no significant differences between α-tubulin and γ-tubulin expression in each group （P〈0.05）, as there was agreement in the immuno-fluorescence and immunohistochemical analysis for protein expression. CONCLUSION There is abnormal expression of centrosome tubulin as an early event in the development of breast tumor. Furthermore these aberrations may play a key role during oncogenesis and promote cellular transformation to malignancy. The immuno-fiuorescence quantitive analysis and immunohistochemistry can complement each other.展开更多
BACKGROUND Pancreatic cancer is a highly invasive malignant tumor. Expression levels of the autophagy-related protein microtubule-associated protein 1 A/1 B-light chain 3(LC3) and perineural invasion(PNI) are closely ...BACKGROUND Pancreatic cancer is a highly invasive malignant tumor. Expression levels of the autophagy-related protein microtubule-associated protein 1 A/1 B-light chain 3(LC3) and perineural invasion(PNI) are closely related to its occurrence and development. Our previous results showed that the high expression of LC3 was positively correlated with PNI in the patients with pancreatic cancer. In this study, we further searched for differential genes involved in autophagy of pancreatic cancer by gene expression profiling and analyzed their biological functions in pancreatic cancer, which provides a theoretical basis for elucidating the pathophysiological mechanism of autophagy in pancreatic cancer and PNI.AIM To identify differentially expressed genes involved in pancreatic cancer autophagy and explore the pathogenesis at the molecular level.METHODS Two sets of gene expression profiles of pancreatic cancer/normal tissue(GSE16515 and GSE15471) were collected from the Gene Expression Omnibus.Significance analysis of microarrays algorithm was used to screen differentially expressed genes related to pancreatic cancer. Gene Ontology(GO) analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway analysis were used to analyze the functional enrichment of the differentially expressed genes. Protein interaction data containing only differentially expressed genes was downloaded from String database and screened. Module mining was carried out by Cytoscape software and ClusterOne plug-in. The interaction relationship between the modules was analyzed and the pivot nodes between the functional modules were determined according to the information of the functional modules and the data of reliable protein interaction network.RESULTS Based on the above two data sets of pancreatic tissue total gene expression, 6098 and 12928 differentially expressed genes were obtained by analysis of genes with higher phenotypic correlation. After extracting the intersection of the two differential gene sets, 4870 genes were determined. GO analysis showed that 14 significant functional items including negative regulation of protein ubiquitination were closely related to autophagy. A total of 986 differentially expressed genes were enriched in these functional items. After eliminating the autophagy related genes of human cancer cells which had been defined, 347 differentially expressed genes were obtained. KEGG pathway analysis showed that the pathways hsa04144 and hsa04020 were related to autophagy. In addition,65 clustering modules were screened after the protein interaction network was constructed based on String database, and module 32 contains the LC3 gene,which interacts with multiple autophagy-related genes. Moreover, ubiquitin C acts as a pivot node in functional modules to connect multiple modules related to pancreatic cancer and autophagy.CONCLUSION Three hundred and forty-seven genes associated with autophagy in human pancreatic cancer were concentrated, and a key gene ubiquitin C which is closely related to the occurrence of PNI was determined, suggesting that LC3 may influence the PNI and prognosis of pancreatic cancer through ubiquitin C.展开更多
The northem pig-tailed macaque （NPM, Macaca leonina） has become a widely used animal model in biomedical research. In this study, we measured serum immunoglobulin IgG, IgM, IgA, complement C3, C4 and CRP levels in 3...The northem pig-tailed macaque （NPM, Macaca leonina） has become a widely used animal model in biomedical research. In this study, we measured serum immunoglobulin IgG, IgM, IgA, complement C3, C4 and CRP levels in 3-11 year old captive northem pig-tailed macaques using HITACHI 7600-20 automated chemistry analyzer in order to determine the influences of age and gender on these items. The results showed that serum IgA, IgM, C3 and C4 levels were not correlated with age （P〉0.05）, while serum IgG levels increased progressively with age （r=0.202; P=0.045）. Serum IgG, IgA, IgM and C3 levels were higher in females than in males （P〈0.05）. Moreover, serum C3 concentration was both positively and strongly correlated with that of C4 （r=0.700; P〈0.0001）. This study provides basic serum immunoglobulin and complement data of captive northem pig-tailed macaques, which may prove useful for future breeding efforts and biomedical research.展开更多
Non-specific lipid transfer proteins(nsLTPs) are small, basic proteins that are characterized by an eight-cysteine motif. The biological functions of these proteins have been reported to involve plant reproduction and...Non-specific lipid transfer proteins(nsLTPs) are small, basic proteins that are characterized by an eight-cysteine motif. The biological functions of these proteins have been reported to involve plant reproduction and biotic or abiotic stress response. With the completion of the barley genome sequence, a genome-wide analysis of nsLTPs in barley(Hordeum vulgare L.)(HvLTPs) will be helpful for understanding the function of nsLTPs in plants. We performed a genome-wide analysis of the nsLTP gene family in barley and identified 70 nsLTP genes,which can be divided into five types(1, 2, C, D, and G). Each type of nsLTPs shares similar exon and intron gene structures. Expression analysis showed that barley nsLTPs have diverse expression patterns, revealing their various roles. Our results shed light on the phylogenetic relationships and potential functions of barley nsLTPs and will be useful for future studies of barley development and molecular breeding.展开更多
AIM： TO investigate the protein profile of human hepatocarcinoma cell line SMMC-7721, to analyze the specific functions of abundant expressed proteins in the processes of hepatocarcinoma genesis, growth and metastasi...AIM： TO investigate the protein profile of human hepatocarcinoma cell line SMMC-7721, to analyze the specific functions of abundant expressed proteins in the processes of hepatocarcinoma genesis, growth and metastasis, to identify the hepatocarcinoma-specific biomarkers for the early prediction in diagnosis, and to explore the new drug targets for liver cancer therapy. METHODS： Total proteins from human hepatocarcinoma cell line SMMC-7721 were separated by two-dimensional electrophoresis （2DE）. The silver-stained gel was analyzed by 2DE software Image Master 2D Elite. Interesting protein spots were identified by peptide mass fingerprinting based on matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry （MALDI-TOF-MS） and database searching. RESULTS： We obtained protein profile of human hepatocarcinoma cell line SMMC-7721. Among the twenty-one successfully identified proteins, mitofilin, endoplasmic reticulum protein ERp29, ubiquinol-cytochrome C reductase complex core protein I, peroxisomal enoyl CoA hydratase, peroxiredoxin-4 and probable 3-oxoacid CoA transferase 1 precursor were the six novel proteins identified in human hepatocarcinoma cells or tissues. Specific functions of the identified heat-shock proteins were analyzed in detail, and the results suggested that these proteins might promote tumorigenesis via inhibiting cell death induced by several cancer-related stresses or via inhibiting apoptosis at multiple points in the apoptotic signal pathway. Other identified chaperones and cancer-related proteins were also analyzed.CONCLUSION： Based on the protein profile of SMMC-7721 cells, functional analysis suggests that the identified chaperones and cancer-related proteins have their own pathways to contribute to the tumorigenesis, tumor growth and metastasis of liver cancer. Furthermore, proteomic analysis is indicated to be feasible in the cancer study.展开更多
Proteomics is the study of proteins and their interactions in a cell. With the successful completion of the Human Cenome Project, it comes the postgenome era when the proteomics technology is emerging. This paper stud...Proteomics is the study of proteins and their interactions in a cell. With the successful completion of the Human Cenome Project, it comes the postgenome era when the proteomics technology is emerging. This paper studies protein molecule from the algebraic point of view. The algebraic system （∑, ＋, ＊） is introduced, where ∑ is the set of 64 codons. According to the characteristics of （∑, ＋, ＊）, a novel quasi-amino acids code classification method is introduced and the corresponding algebraic operation table over the set ZU of the 16 kinds of quasi-amino acids is established. The internal relation is revealed about quasi-amino acids. The results show that there exist some very close correlations between the properties of the quasi-amino acids and the codon. All these correlation relationships may play an important part in establishing the logic relationship between codons and the quasi-amino acids during the course of life origination. According to Ma F et al （2003 J. Anhui Agricultural University 30 439）, the corresponding relation and the excellent properties about amino acids code are very difficult to observe. The present paper shows that （ZU, ＋,×） is a field. Furthermore, the operational results display that the eodon tga has different property from other stop codons. In fact, in the mitochondrion from human and ox genomic codon, tga is just tryptophane, is not the stop codon like in other genetic code, it is the case of the Chen W C et al （2002 Acta Biophysiea Siniea 18（1） 87）. The present theory avoids some inexplicable events of the 20 kinds of amino acids code, in other words it solves the problem of ＇the 64 codon assignments of mRNA to amino acids is probably completely wrong＇ proposed by Yang （2006 Progress in Modern Biomedicine 6 3）.展开更多
The posterior silk gland （PSG） of silkworm is an important organ where fibroin is synthesized and secreted exclusively. Because fibroin constitutes 75-80% of the silk filament, the mechanism governing fibroin secret...The posterior silk gland （PSG） of silkworm is an important organ where fibroin is synthesized and secreted exclusively. Because fibroin constitutes 75-80% of the silk filament, the mechanism governing fibroin secretion, quality and yield of cocoon can be elucidated by the study on the PSG. Using two-dimensional gel electrophoresis （2-DE） and image analysis system, the changes in the protein composition in the PSG cell were investigated on the day 1 （D1） and day 4 （D4） in the 5th instar stage from five different strains of silkworm （Bombyx mori）. While differences at protein level between days and strains were far less than those observed at the gene level using EST analysis. The change trends in protein composition from D1 to D4 were diverse among the different strains. The results suggest that the secretion of fibroin is regulated by multiple proteins. The site of regulation and the proteins responsible for the regulation vary with the strain, which leads to differences between strains in the capacity of fibroin secretion in the PSG cell.展开更多
文摘Many eukaryotic genes are members of multi-gene families due to gene duplications, which generate new copies that allow functional divergence. However, the relationship between
文摘A fundamental goal in cellular signaling is to understand allosteric communication, the process by which sig-nals originating at one site in a protein propagate reliably to affect distant functional sites. The general principles of protein structure that underlie this process remain unknown. Statistical coupling analysis （SCA） is a statistical technique that uses evolutionary data of a protein family to measure correlation between distant functional sites and suggests allosteric communication. In proteins, very distant and small interactions between collections of amino acids provide the communication which can be important for signaling process. In this paper, we present the SCA of protein alignment of the esterase family （pfam ID： PF00756） containing the sequence of antigen 85C secreted by Mycobacterium tuberculosis to identify a subset of interacting residues. Clustering analysis of the pairwise correlation highlighted seven important residue positions in the esterase family alignments. These resi-dues were then mapped on the crystal structure of antigen 85C （PDB ID： 1DQZ）. The mapping revealed corre-lation between 3 distant residues （Asp38, Leu123 and Met125） and suggests allosteric communication between them. This information can be used for a new drug against this fatal disease.
基金Guangdong Provincial Science and Technology Project (2005B40101012,2004B20201013)Guangdong Province supported Agricultural Science and Technology Project (2004-295)
文摘Using HCl to activate the diapause eggs is a traditional technique of artificial hatching applied in silkworm egg production. Its mechanism has not yet been clarified. This experiment explored the effect of HCl on the termination of diapause of silkworm eggs cold-stored for 45 days from the point of proteomes. Two-dimensional electrophoresis techniques and ESI- MS-MS were used to compare and analyze the variation expression of difficult-dissolved-proteins of diapause eggs coldstored for 45 days before and after acid treatment. Through analysis on the two-dimensional electrophoretogram, there were 296 dots before acid treatment and 302 after the treatment, respectively. Amongst them 265 dots were matchable. The matchability reached 88.6%. There were 31 specific protein dots before acid treatment and 37 after acid treatment, respectively. ESI-MS-MS analysis was conducted for two specific protein-rich dots which disappeared after acid treatment. The results indicated that the sequence of No. 1 protein dot had 55 amino acids＇ peptide matched with those of chorion protein （Bombyx mori）. While the sequence of No. 2 protein dot had only 15 amino acids＇ peptide matched with those of heat shock protein hsp 19.9 （Bombyx mori）, and it was presumed to be an unknown protein. The difficult-dissolvedproteins of diapause eggs have variation expression after acid treatment. Some proteins before and after acid treatment are changed in MW.
基金supported by the National Natural Science Foundation of China (Grant No. 11071282)the Chinese Program for New Century Excellent Talents in University (Grant No. NCET-08-06867)+4 种基金the Natural Science Foundation of Hunan Province of China(Grant No. 10JJ7001)the Lotus Scholars Program of Hunan Province of Chinathe Aid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province of Chinathe Australian Research Council (GrantNo. DP0559807)the Postgraduate Research and Innovation Project of Hunan Province of China (Grant No. CX2010B243)
文摘Apoptosis proteins play an important role in the development and homeostasis of an organism. The elucidation of the subcellular locations and functions of these proteins is helpful for understanding the mechanism of programmed cell death. In this paper, the recurrent quantification analysis, Hilbert-Huang transform methods, the maximum relevance and minimum redundancy method and support vector machine are used to predict the subcellular location of apoptosis proteins. The validation of the jackknife test suggests that the proposed method can improve the prediction accuracy of the subcellular location of apoptosis proteins and its application may be promising in other fields.
基金supported by the China Agricultural Research System(nycytx-44-3-2)the Zhejiang Key Project on Agricultural Development through Science and Technology(2011C12028)+1 种基金the National Natural Science Foundation of China(31302068)the Zhejiang Provincial Natural Science Foundation of China(LQ13C180002)
文摘Bordetella bronchiseptica is a Gram-negative pathogen that causes acute and chronic respiratory infection in a variety of animals. To identify useful antigen candidates for diagnosis and subunit vaccine of B. bronchiseptica, immunoproteomic analysis was adopted to analyse outer membrane proteins of it. The outer membrane proteins extracted from B. bronchiseptica were separated by two-dimensional gel electrophoresis and analyzed by Western blotting for their reactivity with the convalescent serum against two strains. Immunogenic proteins were identified by matrix-assisted laser desorption/ionization time of flight-mass spectrometry（MALDI-TOF-MS）, a total of 14 proteins are common immunoreactive proteins, of which 1 was known antigen and 13 were novel immunogenic proteins for B. bronchiseptica. Putative lipoprotein gene was cloned and recombinantly expressed. The recombinant protein induced high titer antibody, but showed low protective indices against challenges with HB（B. bronchiseptica strain isolated from a infected rabbit）. The mortality of mice was 80% compared to 100% of positive controls. The identification of these novel antigenic proteins is an important resource for further development of a new diagnostic test and vaccine for B. bronchiseptica.
基金National natural science foundation of China (30471530)
文摘The amino acid sequences of the NP, P, M, F, HN and L proteins of the paramyxovirus Tianjin strain were analyzed by using the bioinformatics methods. Phylogenetic analysis based on 6 structural proteins among the Tianjin strain and 25 paramyxoviruses showed that the Tianjin strain belonged to the genus Respirovirus, in the subfamily Paramyxovirinae, and was most closely related to Sendai virus (SeV). Phylogenetic analysis with 14 known SeVs showed that Tianjin strain represented a new evolutionary lineage. Similarities comparisons indicated that Tianjin strain P protein was poorly conserved, sharing only 78.7% - 91.9% amino acid identity with the known SeVs, while the L protein was the most conserved, having 96.0% - 98.0% amino acid identity with the known SeVs. Alignments of amino acid sequences of 6 structural proteins clearly showed that Tianjin strain possessed many unique amino acid substitutions in their protein sequences, 15 in NP, 29 in P, 6 in M, 13 in F, 18 in HN, and 29 in L. These results revealed that Tianjin strain was most likely a new genotype of SeV. The presence of unique amino acid substitutions suggests that Tianjin strain maybe has a significant difference in biological, pathological, immunological, or epidemiological characteristics from the known SeVs.
文摘Hypoxia preconditioning （HPC） is associated with many complicated pathophysiological and biochemical processes that integrated and regulated via molecular levels. HPC could protect cells, tissues, organs and systems from hypoxia injury, but up to date, the molecular mechanism still remained unclear. The acute and repetitive hy- poxia preconditioning model was constructed and the related parameters were observed. The high-throughput mi- croarray analysis and multiple bioinformatics were used to explore the differentially expressed genes in HPC mice brain and the related gene network, pathways and biological processes related to HPC. The 2D-DIGE coupled with MALDI-TOF/TOF-MS was performed to identify these proteins that were differentially expressed during HPC. The UPLC-HRMS based metabolomics method was utilized to explore the key endogenous metabolites and metabolic pathways related to HPC. The results showed that （1） 1175 differentially expressed genes in HPC mice brain were identified. Fourteen of these genes were the related hub genes for HPC, including Cacna2dl, Grin2a, Npylr, Mef2c, Epha4, Rxfpl, Chrm3, Pdela, Atp2b4, Glral, Idil , Fgfl, Grin2b and Cda. The change trends of all the detected genes by RT-PCR were consistent with the data of gene chips. There were 113 significant functions up- regulated and 138 significant functions down-regulated in HPC mice. （2） About 2100 proteins were revealed via the gel imaging and spot detection. 66, 45 and 70 of proteins were found to have significantly difference between the control group and three times of HPC group, the control and six times of HPC, and the three times of HPC and six times of HPC group. （3）Some endogenous metabolites such as phenylalanine, valine, proline, leucine and glu- tamine were increased, while ereatine was decreased, both in HPC brain and heart; in addition, y-aminobutyric acid was markedly decreased in brain. The sphingolipid metabolic pathways were noticed due to the low p-value and high pathway impact. Especially, the sphingolipid compound sphingomyelin, ceramide, glucosyleeramide, galactosylceramide and laetosylceramide were mapping in this metabolic pathway. Interestingly, these sphingolipid metabolites with olefinic bond in the long fatty chain were up-regulated, while those sphingolipids without olefinic bond were down-regulated. The functions of these differentially expressed genes mainly involved the cellular proces- ses including MAPK pathway, ion transport, neurotransmitter transport and neuropeptide signal pathway. The pro- tein levels related the ATP synthesis and citric acid cycle decreased while the proteins with the glycolysis and oxy- gen-binding increased. Glutathione, GNBP-1 and GPD1L were related to preventing hypoxic damage. The results indicated that C24：l-Cers played a critical role in HPC and had potential in endogenous protective mechanism. The combinations of the system omies data of the different molecules were sufficient to give a further understanding of the molecular pathways affected by HPC. Our data provided an important insight to reveal the protection mechanism of HPC.
文摘The influence of water temperature on protein composition in the reconstitution of milk powder was evaluated using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF MS）. 11 ion peaks in the matrix-assisted laser desorption/ionization （MALDI） spectra were examined to study the alteration of relative quantities of milk proteins when water at different temperature was employed in the reconstitution of milk powder. A discrepancy factor Dij was implemented to represent the degree of milk proteins＇ denaturation. Data obtained indicated that Dij value increased with rising water temperature, and thermal damage to milk proteins became evidently when the water temperature exceeded 60℃. The results confirmed that nutrient loss occurred when milk proteins denatured in water at high temperatures.
文摘Chronic stress can induce hippocampus injury such as neuron loss and dendrite atrophy,but its mechanism and molecular basis remain unclear up to now.To understand the molecular mechanism on protein level and find the crucial proteins which correlated with chronic
基金supported by the Project from the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (10KJB240001)the Foundation for Talent Recruitment of Yancheng Institute of Technology (XKR2011007)the National Natural Science Foundation of China (30830083)
文摘Peptidoglycan recognition proteins（PGRPs） are a family of pattern recognition receptors（PRRs） of the immune system,which bind and hydrolyze bacterial peptidoglycan.Here,a long type PGRP（PGRP-L） was first cloned in the lower vertebrate species Xenopus tropicalis（Xt）.The XtPGRP-L possessed a conserved genomic structure with five exons and four introns.The alignment and phylogenetic analysis indicated that XtPGRP-L might be a type of amidase-like PGRP.The 3-D model showed that XtPGRP-L possessed a conserved structure compared with the Drosophila PGRP-Lb.During embryonic development,XtPGRP-L was not expressed until the 72 h tadpole stage.In adult tissues,it was strongly expressed in the liver,lung,intestine,and stomach.Furthermore,after LPS stimulation,the expression of XtPGRP-L was up-regulated significantly in the liver,intestine and spleen,indicating that XtPGRP-L may play an important role in the innate immunity of Xenopus tropicalis.
基金supported by The Medical Engineering Cross Research Funding of Shanghai Jiaotong University"Star of Jiaotong University"Program(24X010301595).
文摘Background Lung squamous cell carcinoma(LUSC)is a major subtype of non-small cell lung cancer with a high mortality rate.Identifying causal plasma proteins associated with LUSC could provide new insights into the pathophysiology of the disease and potential therapeutic targets.This study aimed to identify plasma proteins causally linked to LUSC risk using proteome-wide Mendelian randomization(MR)and colocalization analyses.Methods Proteome-wide MR analysis was conducted using data from the UK Biobank Pharma Proteomics Project and deCODE genetics.Summary-level data for LUSC were obtained from the ILCCO Consortium,the FinnGen study,and a separate GWAS study.A total of 1,046 shared protein quantitative trait loci(pQTLs)were analyzed.Sensitivity analyses included the HEIDI test for horizontal pleiotropy and colocalization analysis to validate the causal associations.Results MR analysis identified six plasma proteins associated with LUSC risk:HSPA1L,PCSK7,POLI,SPINK2,TCL1A,and VARS.HSPA1L(OR=0.47;95%CI:0.34–0.65;P=4.89×10^(–6)),SPINK2(OR=0.68;95%CI:0.58–0.80;P=3.17×10^(–6)),and VARS(OR=0.44;95%CI:0.31–0.63;P=5.94×10^(–6))were associated with a decreased risk of LUSC.Conversely,PCSK7(OR=1.37;95%CI:1.21–1.56;P=1.40×10^(–6)),POLI(OR=4.50;95%CI:2.25–9.00;P=2.13×10–5),and TCL1A(OR=1.72;95%CI:1.34–2.21;P=1.89×10–5)were associated with an increased risk.The SMR analysis and HEIDI test confirmed the robustness of these associations.HSPA1L,SPINK2,and VARS showed significant inverse associations,with strong colocalization evidence for TCL1A(PPH4=0.817).Conclusions This study identified six plasma proteins potentially causal for LUSC risk.HSPA1L,SPINK2,and VARS are associated with decreased risk,while PCSK7,POLI,and TCL1A are linked to increased risk.These findings provide new insights into LUSC pathogenesis and highlight potential targets for therapeutic intervention.
基金Supported by the Development Program for Guangxi Science andTechnology(0719004-3G)~~
文摘[ Objective] The study was to clone HN and F genes from GX1 strain of goose paramyxovirus and analyze their sequences. [ Method] According to the full nucleotide sequence of GPV-SF02 strain of goose paramyxovirus, two pairs of pdmers were designed to amplify the HN and F genes from GX1 strain of goose paramyxovirus isolated from diseased goose in Guangxi Zhuang Autonomous Region; the amplified products were ligated into pMD18-T vector and sequenced. [ Result ] HN and F genes of this strain tested were 1 716 and 1 662 bp in full nucleotide length, respectively; both showed the homologues of about 97.3% with GPV- SF02 strain, of 80.3% -97.5% with strains LaSota, F48E9 and JS, of just 84.8% with Miyadera strain. [ Conclusion] The results show that isolated strain BX1 matches to virulent APMV-1 strain, belonging to genotype Ⅶ of APMV-1 strain.
文摘OBJECTIVE To investigate the changes and values of the expression of α-tubulin and γ-tubulin in atypical ductal hyperplasia （ADH）, ductal carcinoma in situ （DCIS） and invasive ductal carcinoma （IDC） of the breast. The relationship between centrosome abnormalities and breast tumor development was further discussed. METHODS There were three groups including ADH, DCIS and IDC with 30 cases in each group. They were analyzed by immuno-fiuorescence quantity analysis. The expression levels of α-tubulin and γ-tubulin protein in these tissues were detected by flow cytometry immuno-fiuorescence analysis and compared with the results from normal tissues. Immunohistochemistry was also performed in this research. RESULTS The results showed significant differences of the average of the positive （FITC labeled） cells （P=0.000） among the four groups. The level of the IDC group was the highest, while normal breast tissue showed the lowest level. The results suggested that the expression levels of α-tubulin and γ-tubulin both increased as the grade of cellular proliferation and differentiation increased. The expressions showed significant differences among all the groups, except between the ADH and DCIS. There were no significant differences between α-tubulin and γ-tubulin expression in each group （P〈0.05）, as there was agreement in the immuno-fluorescence and immunohistochemical analysis for protein expression. CONCLUSION There is abnormal expression of centrosome tubulin as an early event in the development of breast tumor. Furthermore these aberrations may play a key role during oncogenesis and promote cellular transformation to malignancy. The immuno-fiuorescence quantitive analysis and immunohistochemistry can complement each other.
基金Supported by the National Natural Science Foundation of China,No.U1504815 and No.U1504808
文摘BACKGROUND Pancreatic cancer is a highly invasive malignant tumor. Expression levels of the autophagy-related protein microtubule-associated protein 1 A/1 B-light chain 3(LC3) and perineural invasion(PNI) are closely related to its occurrence and development. Our previous results showed that the high expression of LC3 was positively correlated with PNI in the patients with pancreatic cancer. In this study, we further searched for differential genes involved in autophagy of pancreatic cancer by gene expression profiling and analyzed their biological functions in pancreatic cancer, which provides a theoretical basis for elucidating the pathophysiological mechanism of autophagy in pancreatic cancer and PNI.AIM To identify differentially expressed genes involved in pancreatic cancer autophagy and explore the pathogenesis at the molecular level.METHODS Two sets of gene expression profiles of pancreatic cancer/normal tissue(GSE16515 and GSE15471) were collected from the Gene Expression Omnibus.Significance analysis of microarrays algorithm was used to screen differentially expressed genes related to pancreatic cancer. Gene Ontology(GO) analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway analysis were used to analyze the functional enrichment of the differentially expressed genes. Protein interaction data containing only differentially expressed genes was downloaded from String database and screened. Module mining was carried out by Cytoscape software and ClusterOne plug-in. The interaction relationship between the modules was analyzed and the pivot nodes between the functional modules were determined according to the information of the functional modules and the data of reliable protein interaction network.RESULTS Based on the above two data sets of pancreatic tissue total gene expression, 6098 and 12928 differentially expressed genes were obtained by analysis of genes with higher phenotypic correlation. After extracting the intersection of the two differential gene sets, 4870 genes were determined. GO analysis showed that 14 significant functional items including negative regulation of protein ubiquitination were closely related to autophagy. A total of 986 differentially expressed genes were enriched in these functional items. After eliminating the autophagy related genes of human cancer cells which had been defined, 347 differentially expressed genes were obtained. KEGG pathway analysis showed that the pathways hsa04144 and hsa04020 were related to autophagy. In addition,65 clustering modules were screened after the protein interaction network was constructed based on String database, and module 32 contains the LC3 gene,which interacts with multiple autophagy-related genes. Moreover, ubiquitin C acts as a pivot node in functional modules to connect multiple modules related to pancreatic cancer and autophagy.CONCLUSION Three hundred and forty-seven genes associated with autophagy in human pancreatic cancer were concentrated, and a key gene ubiquitin C which is closely related to the occurrence of PNI was determined, suggesting that LC3 may influence the PNI and prognosis of pancreatic cancer through ubiquitin C.
基金Foundation items： This work was supported by the National Natural Science Foundation of China （81172876, U0832601, 81273251, U1202228） the National Special Science Research Program of China （2012CBA01305） the National Science and Technology Major Project （2013ZX10001-002, 2012ZX10001-007） and the Knowledge Innovation Program of CAS （KSCX2-EW-R-13）.
文摘The northem pig-tailed macaque （NPM, Macaca leonina） has become a widely used animal model in biomedical research. In this study, we measured serum immunoglobulin IgG, IgM, IgA, complement C3, C4 and CRP levels in 3-11 year old captive northem pig-tailed macaques using HITACHI 7600-20 automated chemistry analyzer in order to determine the influences of age and gender on these items. The results showed that serum IgA, IgM, C3 and C4 levels were not correlated with age （P〉0.05）, while serum IgG levels increased progressively with age （r=0.202; P=0.045）. Serum IgG, IgA, IgM and C3 levels were higher in females than in males （P〈0.05）. Moreover, serum C3 concentration was both positively and strongly correlated with that of C4 （r=0.700; P〈0.0001）. This study provides basic serum immunoglobulin and complement data of captive northem pig-tailed macaques, which may prove useful for future breeding efforts and biomedical research.
基金supported by funds from the National Key Research and Development Program of China (2016YFD0100903)
文摘Non-specific lipid transfer proteins(nsLTPs) are small, basic proteins that are characterized by an eight-cysteine motif. The biological functions of these proteins have been reported to involve plant reproduction and biotic or abiotic stress response. With the completion of the barley genome sequence, a genome-wide analysis of nsLTPs in barley(Hordeum vulgare L.)(HvLTPs) will be helpful for understanding the function of nsLTPs in plants. We performed a genome-wide analysis of the nsLTP gene family in barley and identified 70 nsLTP genes,which can be divided into five types(1, 2, C, D, and G). Each type of nsLTPs shares similar exon and intron gene structures. Expression analysis showed that barley nsLTPs have diverse expression patterns, revealing their various roles. Our results shed light on the phylogenetic relationships and potential functions of barley nsLTPs and will be useful for future studies of barley development and molecular breeding.
基金Supported by the National Natural Science Foundation of China, No. 30370403the Key Project of Chinese Ministry of Education, No. 705046the Doctoral Foundation of Xi’an Jiaotong University, grants No. DFXJTU2005-05
文摘AIM： TO investigate the protein profile of human hepatocarcinoma cell line SMMC-7721, to analyze the specific functions of abundant expressed proteins in the processes of hepatocarcinoma genesis, growth and metastasis, to identify the hepatocarcinoma-specific biomarkers for the early prediction in diagnosis, and to explore the new drug targets for liver cancer therapy. METHODS： Total proteins from human hepatocarcinoma cell line SMMC-7721 were separated by two-dimensional electrophoresis （2DE）. The silver-stained gel was analyzed by 2DE software Image Master 2D Elite. Interesting protein spots were identified by peptide mass fingerprinting based on matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry （MALDI-TOF-MS） and database searching. RESULTS： We obtained protein profile of human hepatocarcinoma cell line SMMC-7721. Among the twenty-one successfully identified proteins, mitofilin, endoplasmic reticulum protein ERp29, ubiquinol-cytochrome C reductase complex core protein I, peroxisomal enoyl CoA hydratase, peroxiredoxin-4 and probable 3-oxoacid CoA transferase 1 precursor were the six novel proteins identified in human hepatocarcinoma cells or tissues. Specific functions of the identified heat-shock proteins were analyzed in detail, and the results suggested that these proteins might promote tumorigenesis via inhibiting cell death induced by several cancer-related stresses or via inhibiting apoptosis at multiple points in the apoptotic signal pathway. Other identified chaperones and cancer-related proteins were also analyzed.CONCLUSION： Based on the protein profile of SMMC-7721 cells, functional analysis suggests that the identified chaperones and cancer-related proteins have their own pathways to contribute to the tumorigenesis, tumor growth and metastasis of liver cancer. Furthermore, proteomic analysis is indicated to be feasible in the cancer study.
基金Project supported in part by the International Technology Collaboration Research Program of China (Grant No 2007DFA706700)
文摘Proteomics is the study of proteins and their interactions in a cell. With the successful completion of the Human Cenome Project, it comes the postgenome era when the proteomics technology is emerging. This paper studies protein molecule from the algebraic point of view. The algebraic system （∑, ＋, ＊） is introduced, where ∑ is the set of 64 codons. According to the characteristics of （∑, ＋, ＊）, a novel quasi-amino acids code classification method is introduced and the corresponding algebraic operation table over the set ZU of the 16 kinds of quasi-amino acids is established. The internal relation is revealed about quasi-amino acids. The results show that there exist some very close correlations between the properties of the quasi-amino acids and the codon. All these correlation relationships may play an important part in establishing the logic relationship between codons and the quasi-amino acids during the course of life origination. According to Ma F et al （2003 J. Anhui Agricultural University 30 439）, the corresponding relation and the excellent properties about amino acids code are very difficult to observe. The present paper shows that （ZU, ＋,×） is a field. Furthermore, the operational results display that the eodon tga has different property from other stop codons. In fact, in the mitochondrion from human and ox genomic codon, tga is just tryptophane, is not the stop codon like in other genetic code, it is the case of the Chen W C et al （2002 Acta Biophysiea Siniea 18（1） 87）. The present theory avoids some inexplicable events of the 20 kinds of amino acids code, in other words it solves the problem of ＇the 64 codon assignments of mRNA to amino acids is probably completely wrong＇ proposed by Yang （2006 Progress in Modern Biomedicine 6 3）.
文摘The posterior silk gland （PSG） of silkworm is an important organ where fibroin is synthesized and secreted exclusively. Because fibroin constitutes 75-80% of the silk filament, the mechanism governing fibroin secretion, quality and yield of cocoon can be elucidated by the study on the PSG. Using two-dimensional gel electrophoresis （2-DE） and image analysis system, the changes in the protein composition in the PSG cell were investigated on the day 1 （D1） and day 4 （D4） in the 5th instar stage from five different strains of silkworm （Bombyx mori）. While differences at protein level between days and strains were far less than those observed at the gene level using EST analysis. The change trends in protein composition from D1 to D4 were diverse among the different strains. The results suggest that the secretion of fibroin is regulated by multiple proteins. The site of regulation and the proteins responsible for the regulation vary with the strain, which leads to differences between strains in the capacity of fibroin secretion in the PSG cell.
