期刊
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
卷 102, 期 52, 页码 18896-18901出版社
NATL ACAD SCIENCES
DOI: 10.1073/pnas.0506169103
关键词
crystallin; dimer; Synechocystis; thermotolerance; heat stress
资金
- NIGMS NIH HHS [R01 GM042762, R01 GM42762] Funding Source: Medline
To investigate the mechanism of small heat shock protein (sHsp) function, unbiased by current models of sHsp chaperone activity, we performed a screen for mutations of Synechocystis Hsp16.6 that reduced the ability of the protein to provide thermotolerance in vivo. Missense mutations at 17 positions throughout the protein and a C-terminal truncation of 5 aa were identified, representing the largest collection of sHsp mutants impaired in function in vivo. Ten mutant proteins were purified and tested for alterations in native oligomeric structure and in vitro chaperone activity. These biochemical assays separated the mutants into two groups. The C-terminal truncation and six mutations in the alpha-crystallin domain destabilized the sHsp oligomer and reduced in vitro chaperone activity. In contrast, the other three mutations had little effect on oligomer stability or chaperone activity in vitro. These mutations were clustered in the IN terminus of Hsp16.6, pointing to a previously unrecognized, important function for this evolutionarily variable domain. Furthermore, the fact that the N-terminal mutations were impaired in function in vivo, but active as chaperones in vitro, indicates that current biochemical assays do not adequately measure essential features of the sHsp mechanism of action.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据