TGF-beta induces IgA class switching by B cells. We previously reported that Smad3 and Smad4, pivotal TGF-beta signal-transducing transcription factors, mediate germline (GL) alpha transcription induced by TGF-beta1, resulting in IgA switching by mouse B cells. Post-translational sumoylation of Smad3 and Smad4 regulates TGF-beta-induced transcriptional activation in certain cell types. In the present study, we investigated the effect of sumoylation on TGF-beta1-induced, Smad3/4-mediated GLalpha transcription and IgA switching by mouse B cell line, CH12F3-2A. Overexpression of small ubiquitin-like modifier (SUMO)-1, SUMO-2 or SUMO-3 did not affect TGF-beta1-induced, Smad3/4-mediated GLalpha promoter activity, expression of endogenous GLalpha transcripts, surface IgA expression, and IgA production. Next, we tested the effect of the E3 ligase PIASy on TGF-beta1-induced, Smad3/4-mediated GLalpha promoter activity. We found that PIASy overexpression suppresses the GLalpha promoter activity in cooperation with histone deacetylase 1. Taken together, these results suggest that SUMO itself does not affect regulation of GLalpha transcription and IgA switching induced by TGF-beta1/Smad3/4, while PIASy acts as a repressor.
Animals ; B-Lymphocytes* ; Cell Line ; Histone Deacetylase 1 ; Immunoglobulin A ; Immunoglobulin Class Switching ; Mice ; Small Ubiquitin-Related Modifier Proteins* ; SUMO-1 Protein* ; Sumoylation ; Transcription Factors ; Transcriptional Activation ; Transforming Growth Factor beta ; Transforming Growth Factor beta1 ; Ubiquitin-Protein Ligases

To provide technical support for spider silk functional modification, we developed a simple and efficient functional platform via intein trans-splicing. Small ubiquitin-related modifier protein (SUMO) was fused to the recombinant spider silk protein (W2CT) by peptide bond via S0 split intein Ssp DnaB trans-splicing, resulting in a protein SUMOW2CT. However, incorporation of exogenous protein led to mechanical property defect and lower fiber yield, and also slowed down the fiber assembly velocity but no obvious differences in supercontraction and chemical resistance when compared with fibers from W2CT (W). SUMO protease digestion showed positive results on the fibers, indicating that the SUMO protein kept its native conformation and bioactive. Above all, this work provides a technical support for spider silk high simply and efficient functionalized modification.
Animals ; Inteins ; Protein Splicing ; Recombinant Proteins ; chemistry ; Silk ; chemistry ; Small Ubiquitin-Related Modifier Proteins ; chemistry ; Spiders ; Trans-Splicing

OBJECTIVEThe aim of this study is to determine whether the SUMO4 M55V polymorphism is associated with susceptibility to type 2 diabetes mellitus (T2DM).

METHODSA meta-analysis was performed to detect the potential association of the SUMO4 M55V polymorphism and susceptibility to T2DM under dominant, recessive, co-dominant (homogeneous and heterogeneous), and additive models.

RESULTSA total of eight articles including 10 case-control studies, with a total of 2932 cases and 2679 controls, were included in this meta-analysis. The significant association between the SUMO4 M55V polymorphism and susceptibility to T2DM was observed in the dominant model (GG + GA versus AA: OR = 1.21, 95% CI = 1.05-1.40, P = 0.009), recessive model (GG versus GA + AA: OR = 1.29, 95% CI = 1.07-1.356, P = 0.010), homozygous model (GG versus AA: OR = 1.41, 95% CI = 1.06-1.56, P = 0.001), and additive model (G versus A: OR = 1.18, 95% CI = 1.08-1.29, P = 0.001), and marginally significant in the heterozygous model (GA versus AA: OR = 1.16, 95% CI = 0.98-1.36, P = 0.080). In subgroup analyses, significant associations were observed in the Chinese population under four genetic models excluding the heterozygous model, whereas no statistically significant associations were observed in the Japanese population under each of the five genetic models.

CONCLUSIONThe meta-analysis demonstrated that the G allele of the SUMO4 M55V polymorphism could be a susceptible risk locus to T2DM, mainly in the Chinese population, while the association in other ethnic population needs to be further validated in studies with relatively large samples.

Diabetes Mellitus, Type 2 ; epidemiology ; genetics ; Genetic Predisposition to Disease ; epidemiology ; genetics ; Humans ; Small Ubiquitin-Related Modifier Proteins ; genetics ; metabolism

OBJECTIVETo assess the role of small ubiquitin-like modifier 4 (SUMO4) gene polymorphisms (rs237025, rs237024 and rs600739) in the susceptibility to coronary artery disease (CAD) with and without type 2 diabetes mellitus (T2DM) in Chinese Han ethnic population in Beijing.

METHODSIn this case-control study, 558 subjects with angiography-proven CAD were divided into two groups according to the WHO 1999 criteria: 369 with normal glucose tolerance (CAD group) and 189 with T2DM (T2DM+ CAD group). Meanwhile 500 healthy subjects free of T2DM and CAD were selected as normal controls (control group). Allelic and genotypic distributions of the three single nucleotide polymorphisms (SNPs) were determined with polymerase chain reaction-high resolution melting curve (PCR-HRM) and gene sequencing. Clinical and biochemical data were compared among carriers of different genotypes through a stratified analysis.

RESULTSNo significant difference was found in the distribution of genotypes and alleles of each SNP between different groups (P> 0.05). Nevertheless, stratified analysis indicated a significant difference in plasma triglycerides (rs237025) and body mass index (rs600739) among individuals of different genotypes from the T2DM+ CAD group (P= 0.020 and P= 0.049, respectively). Multiple comparison also indicated that GG genotype of rs237025 had a higher level of plasma triglycerides than AA genotype (P< 0.01).

CONCLUSIONNo association between SUMO4 gene polymorphisms and CAD with and without T2DM was detected. Such polymorphisms may not be a risk factor for Chinese Han ethnic patients in Beijing.

Aged ; Case-Control Studies ; Coronary Artery Disease ; genetics ; Diabetes Mellitus, Type 2 ; genetics ; Female ; Genotype ; Humans ; Male ; Middle Aged ; Polymorphism, Single Nucleotide ; Small Ubiquitin-Related Modifier Proteins ; genetics

OBJECTIVETo investigate whether progesterone receptor B (PRB) can be sumoylated by SUMO-2/3 and the effect of sumoylation on PRB transcriptional activity.

METHODSSUMO-2/3 cDNA was amplified from MCF-7 cDNA and cloned into the eukaryotic expression vector pcDNA3-FLAG. The plasmid pXJ40-myc-PRB was cotransfected with pcDNA3FLAG-SUMO2, pcDNA3FLAG-SUMO3 or the mock control into 293T cells, and PRB sumoylation was detected by immunoprecipitation and Western blotting. The effect of PRB sumoylation on its transcriptional activity was determined using reporter luciferase assay.

RESULTSpcDNA3FLAG-SUMO2 and pcDNA3FLAG-SUMO3 vectors were successfully constructed. SUMO-2/3 could bind covalently to PRB and increase its transcriptional dependent on the presence of progesterone.

CONCLUSIONPRB can be sumoylated by SUMO-2/3 and its function is regulated by this modification.

Animals ; Cell Line ; Humans ; Plasmids ; genetics ; Receptors, Progesterone ; genetics ; metabolism ; Small Ubiquitin-Related Modifier Proteins ; genetics ; metabolism ; Transcription, Genetic ; Transfection ; Ubiquitination ; Ubiquitins ; genetics ; metabolism

Zinc finger protein 133 (ZNF133) is composed of a Kruppel-associated box (KRAB) domain and 14 contiguous zinc finger motifs. ZNF133 is regarded as a transcriptional repressor because the KRAB domain has potent repressor activity and the zinc finger motifs usually act in binding to DNA. However, we found that the zinc finger motifs of ZNF133 also possessed transcriptional repressor activity. By two-hybrid screening assay, we found that the zinc finger motifs of ZNF133 interacted with protein inhibitor of activated STAT1 (PIAS1). PIAS1 enhanced the transcriptional repression activity of ZNF133 through the zinc finger motifs. This effect of PIAS1 was relieved by an inhibitor of the histone deacetylases (HDACs). These results demonstrate that the transcriptional repressor activity of ZNF133 is regulated by both the KRAB domain and the zinc finger motifs, and that the repressive effect by zinc finger motifs is mediated by PIAS1.
Cell Line ; DNA-Binding Proteins/*metabolism ; Histone Deacetylases/antagonists & inhibitors/metabolism ; Humans ; Protein Binding ; Protein Inhibitors of Activated STAT/*metabolism ; Protein Structure, Tertiary ; Repressor Proteins/*metabolism ; Small Ubiquitin-Related Modifier Proteins/*metabolism ; Transcription, Genetic ; Two-Hybrid System Techniques ; Zinc Fingers

Nowadays, SUMO fusion system is important for recombinant protein production in Escherichia coli, yet a few aspects remain to be improved, including the efficacy for vector construction and protein solubility. In this study, we found the SUMO gene Smt3 (Sm) of Saccharomyces cerevisiae conferred an unexpected activity of constitutive prokaryotic promoter during its PCR cloning, and the gene coding regions of SUMOs in most species had a sigma70-dependent prokaryotic promoter embedded, through the prediction via the BPROM program developed by Softberry. By combining the characters of Sm promoter activity and the Stu I site (added at the 3'-terminal of Sm), and introducing a His-tag and a hyper-acidic solubility-enhancing tag, we further constructed a set of versatile vectors for gene cloning and expression on the basis of Sm'-LacZa fusion gene. Experimentally started from these vectors, several target genes were subcloned and expressed through blue-white screening and SDS-PAGE analysis. The results manifest a few of expectable advantages such as rapid vector construction, highly soluble protein expression and feasible co-expression of correlated proteins. Conclusively, our optimized SUMO fusion technology herein could confer a large potential in E. coli protein expression system, and the simultaneously established co-expression vector systems could also be very useful in studying the protein-protein interactions in vivo.
Amino Acid Sequence ; Base Sequence ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; genetics ; Lac Operon ; genetics ; Molecular Sequence Data ; Promoter Regions, Genetic ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Saccharomyces cerevisiae Proteins ; biosynthesis ; genetics ; Small Ubiquitin-Related Modifier Proteins ; biosynthesis ; genetics ; Sumoylation

The cDNA of human FGF-21 was subcloned into the pSUMO expression vector and the fusion protein was induced to express in Escherichia coli Rosetta (DE3). The recombinant hFGF-21 was expressed in soluble form in the pSUMO expression system. The recombinant fusion protein was purified by Ni-NTA column. The purified recombinant protein was dialyzed against PBS for re-nature. To obtain pure and active recombinant protein, the fusion protein was subjected to cleavage with SUMO protease I. To examine glucose regulation activity of hFGF-21, 3T3-L1 pre-adipocytes were differentiated into adipocytes, glucose up-take activity of hFGF-21 was examined by glucose oxidase and peroxidase (GOD-POD) assay. Compared with no stimulation control, the recombinant hFGF-21 treatment led to a significant increase in glucose consumption of adipocytes and a significant decrease in concentration of glucose in the medium (P < 0.05, P < 0.001).
3T3-L1 Cells ; Adipocytes ; metabolism ; Animals ; DNA, Complementary ; genetics ; Escherichia coli ; genetics ; metabolism ; Fibroblast Growth Factors ; genetics ; metabolism ; pharmacology ; Glucose ; metabolism ; Humans ; Mice ; Plasmids ; Recombinant Fusion Proteins ; genetics ; metabolism ; pharmacology ; Small Ubiquitin-Related Modifier Proteins ; genetics ; metabolism ; Solubility

The study aims to investigate the associations of SUMO4 polymorphisms with tacrolimus concentrations in Chinese renal transplant recipients. Blood samples and clinical data were collected from 132 renal transplant recipients with tacrolimus treatment. CYP3A5*3 genotypes were detected by PCR-RFLP, and SUMO4 (rs237024, rs237025) genotypes were detected by Sequenom® MassARRAY system. SUMO4 rs237024 and rs237025 genotypes were in complete linkage disequilibrium (D' = 1). The dose-adjusted concentration of tacrolimus in SUMO4 rs237024A-rs237025A (GA-GA +AA-AA) carriers was considerably higher than that in GG-GG carriers (P < 0.05). After stratification by CYP3A5*3 genotypes, SUMO4 rs237024A-rs237025A carriers (GA-GA+AA-AA) had a higher dose-adjusted tacrolimus concentration than that in GG carriers in CYP3A5 expresser (P < 0.05). The results illustrated that SUMO4 rs237024 and rs237025 polymorphisms were associated with tacrolimus concentrations, and the test of these genotypes may be useful for individualized medicine of tacrolimus.
Asian Continental Ancestry Group ; genetics ; Cytochrome P-450 CYP3A ; genetics ; Genotype ; Humans ; Immunosuppressive Agents ; blood ; therapeutic use ; Kidney ; Kidney Transplantation ; Linkage Disequilibrium ; Polymorphism, Single Nucleotide ; Small Ubiquitin-Related Modifier Proteins ; genetics ; Tacrolimus ; blood ; therapeutic use

Autophagy is a self-degradation system of cellular components through an autophagosomal-lysosomal pathway. Over the last 15 yr, yeast genetic screens led to the identification of a number of genes involved in the autophagic pathway. Most of these autophagy genes are present in higher eukaryotes and regulate autophagy process for cell survival and homeostasis. Significant progress has recently been made to better understand the molecular mechanisms of the autophagy machinery. Especially, autophagy process, including the regulation of autophagy induction through mTOR and the nucleation and elongation in autophagosome formation through class III phosphatidylinositol 3-kinase complex and ubiquitin-like conjugation systems, became evident. While many unanswered questions remain to be answered, here, we summarize the recent process of autophagy with emphasis on molecules and their protein complexes along with advanced molecular mechanisms that regulate the autophagy machinery.
Autophagy/genetics/*physiology ; Carrier Proteins/genetics/metabolism ; Class III Phosphatidylinositol 3-Kinases/genetics/metabolism ; Humans ; Intracellular Signaling Peptides and Proteins/genetics/metabolism ; Membrane Proteins/genetics/metabolism ; Microtubule-Associated Proteins/genetics/metabolism ; Models, Biological ; Protein-Serine-Threonine Kinases/genetics/metabolism ; Small Ubiquitin-Related Modifier Proteins/genetics/metabolism