大肠杆菌中HslVU蛋白酶对细胞分裂抑制剂SulA的ATP依赖性降解。

ATP-dependent degradation of SulA, a cell division inhibitor, by the HslVU protease in Escherichia coli.

作者信息

Seong I S, Oh J Y, Yoo S J, Seol J H, Chung C H

机构信息

Department of Molecular Biology and Research Center for Cell Differentiation, College of Natural Sciences, Seoul National University, South Korea.

出版信息

FEBS Lett. 1999 Jul 30;456(1):211-4. doi: 10.1016/s0014-5793(99)00935-7.

DOI:10.1016/s0014-5793(99)00935-7

PMID:10452560

Abstract

HslVU is an ATP-dependent protease consisting of two multimeric components, the HslU ATPase and the HslV peptidase. To gain an insight into the role of HslVU in regulation of cell division, the reconstituted enzyme was incubated with SulA, an inhibitor of cell division in Escherichia coli, or its fusion protein with maltose binding protein (MBP). HslVU degraded both proteins upon incubation with ATP but not with its nonhydrolyzable analog, ATPgammaS, indicating that the degradation of SulA requires ATP hydrolysis. The pulse-chase experiment using an antibody raised against MBP-SulA revealed that the stability of SulA increased in hsl mutants and further increased in lon/hsl double mutants, indicating that SulA is an in vivo substrate of HslVU as well as of protease La (Lon). These results suggest that HslVU in addition to Lon plays an important role in regulation of cell division through degradation of SulA.

摘要

HslVU是一种依赖ATP的蛋白酶，由两个多聚体组分组成，即HslU ATP酶和HslV肽酶。为了深入了解HslVU在细胞分裂调控中的作用，将重组酶与大肠杆菌细胞分裂抑制剂SulA或其与麦芽糖结合蛋白（MBP）的融合蛋白一起孵育。HslVU在与ATP孵育时会降解这两种蛋白质，但与不可水解的类似物ATPγS孵育时则不会，这表明SulA的降解需要ATP水解。使用针对MBP - SulA产生的抗体进行的脉冲追踪实验表明，SulA在hsl突变体中的稳定性增加，而在lon/hsl双突变体中进一步增加，这表明SulA是HslVU以及蛋白酶La（Lon）的体内底物。这些结果表明，除了Lon之外，HslVU在通过降解SulA调控细胞分裂中也起着重要作用。