Insights into the Allosteric Effect of SENP1 Q597A Mutation on the Hydrolytic Reaction of SUMO1 via an Integrated Computational Study

Small ubiquitin-related modifier (SUMO)-specific protease 1 (SENP1) is a cysteine protease that catalyzes the cleavage of the C-terminus of SUMO1 for the processing of SUMO precursors and deSUMOylation of target proteins. SENP1 is considered to be a promising target for the treatment of hepatocellular carcinoma (HCC) and prostate cancer. SENP1 Gln597 is located at the unstructured loop connecting the helices α4 to α5. The Q597A mutation of SENP1 allosterically disrupts the hydrolytic reaction of SUMO1 through an unknown mechanism. Here, extensive multiple replicates of microsecond molecular dynamics (MD) simulations, coupled with principal component analysis, dynamic cross-correlation analysis, community network analysis, and binding free energy calculations, were performed to elucidate the detailed mechanism. Our MD simulations showed that the Q597A mutation induced marked dynamic conformational changes in SENP1, especially in the unstructured loop connecting the helices α4 to α5 which the mutation site occupies. Moreover, the Q597A mutation caused conformational changes to catalytic Cys603 and His533 at the active site, which might impair the catalytic activity of SENP1 in processing SUMO1. Moreover, binding free energy calculations revealed that the Q597A mutation had a minor effect on the binding affinity of SUMO1 to SENP1. Together, these results may broaden our understanding of the allosteric modulation of the SENP1−SUMO1 complex.     

Optimized method for the recombinant production of a sea anemone’s peptide

The production of the analgesic peptide HCRG21 for medical use is restricted by a number of limitations in the technology. The optimal biotechnological method scalable to industrial has been developed based on the production of a fusion protein containing a special leader, His-tag, and Smt3 sequence upstream in the peptide sequence. The resulting peptide shared its inhibitory activity to TRPV1 ion channel identical to the published early.     

Total Chemical Synthesis of SUMO and SUMO‐Based Probes for Profiling the Activity of SUMO‐Specific Proteases

SUMO is a post‐translational modifier critical for cell cycle progression and genome stability that plays a role in tumorigenesis, thus rendering SUMO‐specific enzymes potential pharmacological targets. However, the systematic generation of tools for the activity profiling of SUMO‐specific enzymes has proven challenging. We developed a diversifiable synthetic platform for SUMO‐based probes by using a direct linear synthesis method, which permits N‐ and C‐terminal labelling to incorporate dyes and reactive warheads, respectively. In this manner, activity‐based probes (ABPs) for SUMO‐1, SUMO‐2, and SUMO‐3‐specific proteases were generated and validated in cells using gel‐based assays and confocal microscopy. We further expanded our toolbox with the synthesis of a K11‐linked diSUMO‐2 probe to study the proteolytic cleavage of SUMO chains. Together, these ABPs demonstrate the versatility and specificity of our synthetic SUMO platform for in vitro and in vivo characterization of the SUMO protease family.     

利用核磁共振法探讨类泛素媒介的信息传导分子机制

转译后类泛素修饰调控多项细胞活动,此信息传导的途径为：第一步将类泛素(SUMO)接于E1 活化蛋白,第二步将SUMO 转移到E2 共轭蛋白(Ubc9),然后帮助受体蛋白完成类泛素化,最后借由蛋白酶去除类泛素完成整个传导过程．受体蛋白的类泛素化调控基本上靠Ubc9 来辨识受体蛋白上的特殊类泛素序列(SM),在某些情况下亦可借由E3 辨识完成．而类泛素辨识序列功效的发挥则依赖于招慕含有类泛素辨识序列(SIM)的感应蛋白来实现．此外原核细胞的类泛素化皆有形成多聚类泛素(poly-SUMO)化的能力．多聚类泛素化修饰可被含多聚类泛素辨识序列(poly-SIM)的蛋白质如RNF4 识别,促进受体蛋白的多聚类泛素化,并导致目标蛋白的分解．该文综述了作者所在研究组近年来利用核磁共振法研究类泛素介导的信息传导分子机制方面的成果．