BACKGROUND: Sarcoplasmic reticulum calcium ATPase 2a (SERCA2a) is a key protein that maintains myocardial Ca 2+ homeostasis. The present study aimed to investigate the mechanism underlying the SERCA2a-SUMOylation (small ubiquitin-like modifier) process after ischemia/reperfusion injury (I/RI) in vitro and in vivo . METHODS: Calcium transient and systolic/diastolic function of cardiomyocytes isolated from Serca2a knockout (KO) and wild-type mice with I/RI were compared. SUMO-relevant protein expression and localization were detected by quantitative real-time PCR (RT-qPCR), Western blotting, and immunofluorescence in vitro and in vivo . Serca2a-SUMOylation, infarct size, and cardiac function of Senp1 or Senp2 overexpressed/suppressed adenovirus infected cardiomyocytes, were detected by immunoprecipitation, triphenyltetrazolium chloride (TTC)-Evans blue staining, and echocardiography respectively. RESULTS: The results showed that the changes of Fura-2 fluorescence intensity and contraction amplitude of cardiomyocytes decreased in the I/RI groups and were further reduced in the Serca2a KO + I/RI groups. Senp1 and Senp2 messenger ribose nucleic acid (mRNA) and protein expression levels in vivo and in cardiomyocytes were highest at 6 h and declined at 12 h after I/RI. However, the highest levels in HL-1 cells were recorded at 12 h. Senp2 expression increased in the cytoplasm, unlike that of Senp1. Inhibition of Senp2 protein reversed the I/RI-induced Serca2a-SUMOylation decline, reduced the infarction area, and improved cardiac function, while inhibition of Senp1 protein could not restore the above indicators. CONCLUSION I/RI activated Senp1 and Senp2 protein expression, which promoted Serca2a-deSUMOylation, while inhibition of Senp2 expression reversed Serca2a-SUMOylation and improved cardiac function.
Animals ; Mice ; Calcium/metabolism* ; Cysteine Endopeptidases/metabolism* ; Myocardial Reperfusion Injury/metabolism* ; Myocardium/metabolism* ; Myocytes, Cardiac/metabolism* ; Proteins/metabolism* ; Sarcoplasmic Reticulum Calcium-Transporting ATPases/genetics*

Objective: To inhibit the stemness maintenance potential of endometrial cancer and increase the sensitivity of endometrial cancer side population cells to chemotherapy drugs by inducing extensive deSUMOylation modification of proteins. Methods: Flow cytometry was used to sort and culture CD133(+) CD44(+) KLE endometrial cancer cell clone spheres. Protein expression level of small ubiquitin-related modifier 1 (SUMO1) and two stemness maintenance genes of tumor side population cells, octamer binding transcription factor-4 (Oct4) and sex determining region Y-box2 (Sox2), were detected by western blotting method. Lentivirus-mediated Sentrin/SUMO-specific proteases 1 (SENP1) gene was stably transfected into KLE side population cells. Western blotting was used to detect the protein expressions of SENP1, SUMO1, Oct4 and Sox2. The clone formation rate was compared between KLE side population cells with or without SENP1 overexpression. Flow cytometry was applied to detect cell cycle changes. 3-(4, 5-Dimethylthiazole-2)-2, 5-diphenyl-tetrazolium bromide (MTT) experiment and flow cytometry apoptosis method were used to detect the chemosensitivity of the side population of endometrial cancer cells to cisplatin. Tumor-bearing mouse models of endometrial cancer were established to detect the effect of SENP1 overexpression on the chemotherapy sensitivity of cisplatin. Results: Compared with CD133(-)CD44(-) KLE cells, CD133(+) CD44(+) KLE side population cells could form clonal spheres and express higher levels of SUMO1, Oct4 and Sox2 proteins (P<0.05). Compared with KLE side population cells that were not transfected with SENP1 gene, the expression level of SENP1 protein in KLE side population cells overexpressing SUMO1、Oct4 and Sox2 were lower. The clonal sphere formation rate was reduced from (25.67±5.44)% to (7.46±1.42)%, and cell cycle shifted from G(0)/G(1) phase to G(2) phase. IC(50) of cisplatin decreased from (55.46±6.14) μg/ml to (11.55±3.12) μg/ml, and cell apoptosis rate increased from (9.76±2.09)% to (16.79±3.44)%. Overexpression of SENP1 could reduce the tumorigenesis rate of KLE side population cells in vivo and increase their chemotherapy sensitivity to cisplatin (P<0.05). Conclusion: Overexpression of SENP1 can induce protein deSUMOylation modification, inhibit the stemness maintenance potential of endometrial cancer side population cells, and enhance their chemotherapy sensitivity, which provides a new reference for gene therapy of endometrial cancer.
Animals ; Female ; Humans ; Mice ; Apoptosis ; Cell Line, Tumor ; Cisplatin/pharmacology* ; Cysteine Endopeptidases/metabolism* ; Endometrial Neoplasms/genetics* ; Side-Population Cells/pathology* ; Sumoylation

The main protease (Mpro) of SARS-CoV-2 is a highly conserved and mutation-resistant coronaviral enzyme, which plays a pivotal role in viral replication, making it an ideal target for the development of novel broad-spectrum anti-coronaviral drugs. In this study, a codon-optimized Mpro gene was cloned into pET-21a and pET-28a expression vectors. The recombinant plasmids were transformed into E. coli Rosetta(DE3) competent cells and the expression conditions were optimized. The highly expressed recombinant proteins, Mpro and Mpro-28, were purified by HisTrapTM chelating column and its proteolytic activity was determined by a fluorescence resonance energy transfer (FRET) assay. The FRET assay showed that Mpro exhibits a desirable proteolytic activity (25 000 U/mg), with Km and kcat values of 11.68 μmol/L and 0.037/s, respectively. The specific activity of Mpro is 25 times that of Mpro-28, a fusion protein carrying a polyhistidine tag at the N and C termini, indicating additional residues at the N terminus of Mpro, but not at the C terminus, are detrimental to its proteolytic activity. The preparation of active SARS-CoV-2 Mpro through codon-optimization strategy might facilitate the development of the rapid screening assays for the discovery of broad-spectrum anti-coronaviral drugs targeting Mpro.
COVID-19 ; Codon/genetics* ; Cysteine Endopeptidases/genetics* ; Escherichia coli/genetics* ; Humans ; Peptide Hydrolases ; SARS-CoV-2 ; Viral Nonstructural Proteins/genetics*

OBJECTIVE: To investigate the effect of sodium valproate (VPA) on activation of miR-34c-5p/ATG4B signaling pathway and autophagy in SH-SY5Y cells. METHODS: Routinely cultured SH-SY5Y cells were treated with VPA at different doses for 24 h, and the changes in the mRNA levels of ATG4B and miR-34c-5p and the protein expression of ATG4B were assessed using qRTPCR and immunoblotting, respectively. The effect of transfection with a plasmid containing ATG4B promoter on the promoter activity of ATG4B in VPA-treated SH-SY5Y cells was assessed using the reporter gene assay. The stability of ATG4B mRNA was analyzed with qPCR in SH-SY5Y cells treated with VPA alone or with VPA combined with the transcription inhibitor actinomycin D. The expression level of miR-34c-5p was detected using qPCR in SH-SY5Y cells treated with VPA alone or with VPA combined with miR-34c-5p mimics or antagonist, and the role of miR-34c-5p in VPA-induced ATG4B down-regulation was evaluated. The changes in the level of autophagy were evaluated by detecting LC3-Ⅱ expression in the cells after treatment with VPA or VPA combined with miR-34c-5p antagonist. RESULTS: VPA dose-dependently down-regulated the expression of ATG4B at both the mRNA and protein levels in SH-SY5Y cells. VPA treatment did not significantly affect the promoter activity of ATG4B, but obviously lowered the mRNA stability of ATG4B in SH-SY5Y cells. VPA treatment up-regulated the expression of miR-34c-5p, and the miR-34c-5p antagonist reversed VPA-induced down-regulation of ATG4B in SH-SY5Y cells. VPA also down-regulated the expression level of LC3-Ⅱ in SH-SY5Y cells. CONCLUSIONS VPA suppresses autophagy in SH-SY5Y cells possibly via activating miR-34c-5p/ATG4B signaling pathway.
Autophagy ; drug effects ; Autophagy-Related Proteins ; genetics ; metabolism ; Cell Line ; Cysteine Endopeptidases ; genetics ; metabolism ; Dactinomycin ; pharmacology ; Down-Regulation ; Genes, Reporter ; Humans ; MicroRNAs ; antagonists & inhibitors ; metabolism ; Microtubule-Associated Proteins ; metabolism ; RNA, Messenger ; metabolism ; Signal Transduction ; drug effects ; Transfection ; Valproic Acid ; administration & dosage ; antagonists & inhibitors ; pharmacology

BACKGROUNDProteasome subunits (PSMB) and transporter associated with antigen processing (TAP) loci are located in the human leukocyte antigen (HLA) Class II region play important roles in immune response and protein degradation in neurodegenerative diseases. This study aimed to explore the association between single nucleotide polymorphisms (SNPs) of PSMB and TAP and Parkinson's disease (PD).

METHODSA case-control study was conducted by genotyping SNPs in PSMB8, PSMB9, TAP1, and TAP2 genes in the Chinese population. Subjects included 542 sporadic patients with PD and 674 healthy controls. Nine identified SNPs in PSMB8, PSMB9, TAP1, and TAP2 were genotyped through SNaPshot testing.

RESULTSThe stratified analysis of rs17587 was specially performed on gender. Data revealed that female patients carry a higher frequency of rs17587-G/G versus (A/A + G/A) compared with controls. But there was no significant difference with respect to the genotypic frequencies of the SNPs in PSMB8, TAP1, and TAP2 loci in PD patients.

CONCLUSIONChinese females carrying the rs17587-G/G genotype in PSMB9 may increase a higher risk for PD, but no linkage was found between other SNPs in HLA Class II region and PD.

ATP-Binding Cassette Sub-Family B Member 2 ; genetics ; ATP-Binding Cassette, Sub-Family B, Member 3 ; genetics ; Adult ; Aged ; Antigen Presentation ; Case-Control Studies ; Cysteine Endopeptidases ; genetics ; Female ; Humans ; Male ; Middle Aged ; Parkinson Disease ; genetics ; immunology ; Polymorphism, Single Nucleotide ; Proteasome Endopeptidase Complex ; genetics

SUMOylation is recently found to function as a targeting signal for the degradation of substrates through the ubiquitin-proteasome system. RNF4 is the most studied human SUMO-targeted ubiquitin E3 ligase. However, the relationship between SUMO proteases, SENPs, and RNF4 remains obscure. There are limited examples of the SENP regulation of SUMO2/3-targeted proteolysis mediated by RNF4. The present study investigated the role of SENP3 in the global protein turnover related to SUMO2/3-targeted ubiquitination and focused in particular on the SENP3 regulation of the stability of Sp1. Our data demonstrated that SENP3 impaired the global ubiquitination profile and promoted the accumulation of many proteins. Sp1, a cancer-associated transcription factor, was among these proteins. SENP3 increased the level of Sp1 protein via antagonizing the SUMO2/3-targeted ubiquitination and the consequent proteasome-dependent degradation that was mediated by RNF4. De-conjugation of SUMO2/3 by SENP3 attenuated the interaction of Sp1 with RNF4. In gastric cancer cell lines and specimens derived from patients and nude mice, the level of Sp1 was generally increased in parallel to the level of SENP3. These results provided a new explanation for the enrichment of the Sp1 protein in various cancers, and revealed a regulation of SUMO2/3 conjugated proteins whose levels may be tightly controlled by SENP3 and RNF4.
Animals ; Cysteine Endopeptidases ; genetics ; metabolism ; Gene Expression Regulation, Neoplastic ; Humans ; Immunoenzyme Techniques ; Immunoprecipitation ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Prognosis ; Protein Processing, Post-Translational ; Proteolysis ; RNA, Messenger ; genetics ; Real-Time Polymerase Chain Reaction ; Reverse Transcriptase Polymerase Chain Reaction ; Small Ubiquitin-Related Modifier Proteins ; antagonists & inhibitors ; genetics ; metabolism ; Sp1 Transcription Factor ; genetics ; metabolism ; Stomach Neoplasms ; genetics ; metabolism ; pathology ; Sumoylation ; Tumor Cells, Cultured ; Ubiquitination ; Ubiquitins ; antagonists & inhibitors ; genetics ; metabolism ; Xenograft Model Antitumor Assays

BACKGROUNDNon-small cell lung cancer (NSCLC) is one of the most common malignant tumors. Despite the advances in therapy over the years, its mortality remains high. The aim of this study was to evaluate the expression of small ubiquitin-like modifier (SUMO) proteases 1 (SENP1) in NSCLC tissues and its role in the regulation of vascular endothelial growth factor (VEGF) expression. We also investigated the association between the expression level of SENP1 and the clinicopathological features and survival of the patients.

METHODSA SENP1 small interfering RNA (siRNA) was constructed and transfected into the NSCLC cells. VEGF gene expression was analyzed by real-time polymerase chain reaction (RT-PCR). Immunohistochemistry staining was used to assess the expression of SENP1 in 100 NSCLC patients and its association with the clinicopathological features and survival was analyzed.

RESULTSVEGF expression was significantly higher in NSCLC tissues than in normal lung tissues. Inhibition of SENP1 by siRNA was associated with decreased VEGF expression. SENP1 was over-expressed in 55 of the 100 NSCLC samples (55%) and was associated with a moderate and low histological tumor grade (3.6%, 38.2%, and 58.2% in high, moderate and low differentiated tumors, respectively, P = 0.046), higher T stage (10.9% in T1, and 89.1% in T2 and T3 tumor samples, P < 0.001) and TNM stage (10.9% in stage I, and 89.1% in stages II and III tumor samples, P < 0.001). The rate of lymph node metastasis was significantly higher in the SENP1 over-expression group (76.4%) than that in the SENP1 low expression group (33.3%, P < 0.001). Sixty three patients received postoperative chemotherapy, including 34 with SENP1 over-expression and 29 with SENP1 low expression. Among the 34 patients with SENP1 over-expression, 22 (64.7%) patients developed recurrence or metastasis, significantly higher than those in the low expression group 27.6% (8/29) (P = 0.005). Multivariate Cox regression analysis showed that lymph node metastasis (P = 0.015), TNM stage (P = 0.001), and SENP1 expression level (P = 0.002) were independent prognostic factors for the survival of NSCLC patients.

CONCLUSIONSSENP1 may be a promising predictor of survival, a predictive factor of chemo-sensitivity for NSCLC patients, and potentially a desirable drug target for lung carcinoma target therapy.

Antineoplastic Agents ; therapeutic use ; Blotting, Western ; Carcinoma, Non-Small-Cell Lung ; drug therapy ; genetics ; metabolism ; Cell Line, Tumor ; Cysteine Endopeptidases ; Endopeptidases ; genetics ; metabolism ; Female ; Humans ; Immunohistochemistry ; In Vitro Techniques ; Lung Neoplasms ; drug therapy ; genetics ; metabolism ; Male ; Reverse Transcriptase Polymerase Chain Reaction

Efforts on directed evolution of sortase A to optimize its catalytic properties have been undertaken and shown the promise. To facilitate screening of sortase A mutants with expected catalytic properties, a novel ligation efficiency monitoring system, including reporter substrates GFP-LPETG and GGGYK-Biotin, was developed. GFP-LPETG, wild type sortase A, and a recently reported high activity sortase A mutant were prepared recombinantly from Escherichia coli BL21 (DE3). Taking advantage of the newly designed reporter system, the ligation efficiency catalyzed by wild type and mutant form of sortase A could be sensitively monitored via SDS-PAGE directly. Consistent with previous report, the mutant sortase A displayed much higher catalytic activity compared to wild type enzyme, indicating the new reporter system is easily and fast handled and sensitive. The application of this reporter system into systemic screening will facilitate future directed optimization of sortase A.
Aminoacyltransferases ; genetics ; metabolism ; Bacterial Proteins ; genetics ; metabolism ; Biocatalysis ; Biotin ; Cysteine Endopeptidases ; genetics ; metabolism ; Electrophoresis, Polyacrylamide Gel ; Escherichia coli ; Genes, Reporter ; Ligation ; Mutant Proteins ; genetics ; metabolism

Establishment of recombinant porcine reproductive and respiratory syndrome virus (PRRSV) with co-expression E2 Epitope of Classical Swine Fever virus (CSFV) is a crucial step to develop a genetic engineered vaccine against PRRSV and CSFV. Reverse genetic manipulation could be adopted as a com monly used technique. In this study, we focus on using nonessential regions of NSP2 (aa480-532 and aa508-532) as viral vector to express E2 Epitope of CSFV. A neutralizing epitope of classical swine fever virus (CSFV) E2 protein was inserted into the two nonessential region of nsp2 by the method of mutant PCR, basing on the infectious clone of HuN4-F112 vaccine strain. The co-expressed full-length cDNA clones (psk-HuN4-F112-delta508-532 + E2 and psk-HuN4-F112-delta480-532 + E2) were assembled by cloning and splice of the gene fragments. The completely assembled full-length cDNA clones were confirmed by sequence and Swa I enzyme digestion. Capped RNAs were transcribed in vitro from a full-length cDNA clone of the viral genome and transfected into BHK-21 cells by liposome to acquire the rescued virus. The rescued recombinant viruses were passaged on MARC-145 cells. The successfully rescued viruses were tested by RT-PCR, digestion, and genome sequence. The results showed that these rescued viruses could be distinguished from the parental virus (HuN4-F112) with the mutant genetic marker (Mlu I enzyme site of virual genome at 14 667nt was created by synonymous mutation) and the inserted nsp2 gene region. The results of IFA showed that the inserted E2 epitope could be expressed by the recombinant viruses and the E2 epitope gene was stable during the viral serial passage. The results of plaque assay and viral growth curve showed that the recovery viruses possessed similar characterses of viral growth to those of the parental virus. In summary, the full-length infectious cDNA clones containing the marker gene were constructed and the marker recombinant viruses were rescued. The results suggested that these stable infectious clones could be used as an important tool for development of novel vaccine against PRRSV.
Base Sequence ; Cysteine Endopeptidases ; genetics ; Epitopes ; genetics ; Molecular Sequence Data ; Porcine respiratory and reproductive syndrome virus ; genetics ; Viral Envelope Proteins ; genetics ; immunology ; Viral Vaccines ; immunology

Streptococcus mutans is a common Gram-positive bacterium and plays a significant role in dental caries. Tobacco and/or nicotine have documented effects on S. mutans growth and colonization. Sortase A is used by many Gram-positive bacteria, including S. mutans, to facilitate the insertion of certain cell surface proteins, containing an LPXTGX motif such as antigen I/II. This study examined the effect of nicotine on the function of sortase A to control the physiology and growth of S. mutans using wild-type S. mutans NG8, and its isogenic sortase-defective and -complemented strains. Briefly, the strains were treated with increasing amounts of nicotine in planktonic growth, biofilm metabolism, and sucrose-induced and saliva-induced antigen I/II-dependent biofilm formation assays. The strains exhibited no significant differences with different concentrations of nicotine in planktonic growth assays. However, they had significantly increased (P≤0.05) biofilm metabolic activity (2- to 3-fold increase) as the concentration of nicotine increased. Furthermore, the sortase-defective strain was more sensitive metabolically to nicotine than the wild-type or sortase-complemented strains. All strains had significantly increased sucrose-induced biofilm formation (2- to 3-fold increase) as a result of increasing concentrations of nicotine. However, the sortase-defective strain was not able to make as much sucrose- and saliva-induced biofilm as the wild-type NG8 did with increasing nicotine concentrations. These results indicated that nicotine increased metabolic activity and sucrose-induced biofilm formation. The saliva-induced biofilm formation assay and qPCR data suggested that antigen I/II was upregulated with nicotine but biofilm was not able to be formed as much as wild-type NG8 without functional sortase A.
Amino Acid Motifs ; Aminoacyltransferases ; drug effects ; genetics ; Antigens, Bacterial ; drug effects ; Bacterial Adhesion ; drug effects ; Bacterial Proteins ; drug effects ; genetics ; Biofilms ; drug effects ; Cysteine Endopeptidases ; drug effects ; genetics ; Dose-Response Relationship, Drug ; Humans ; Mutation ; genetics ; Nicotine ; administration & dosage ; pharmacology ; Peptidoglycan ; drug effects ; genetics ; Saliva ; physiology ; Streptococcus mutans ; drug effects ; enzymology ; growth & development ; Sucrose ; pharmacology