期刊
FEBS JOURNAL
卷 279, 期 7, 页码 1339-1352出版社
WILEY
DOI: 10.1111/j.1742-4658.2012.08528.x
关键词
AAA ATPase; heteronuclear NMR; microtubule-severing enzyme; molecular modeling; three-dimensional domain rearrangement
资金
- Grants-in-Aid for Scientific Research [23570193, 21113007, 22570118] Funding Source: KAKEN
Katanin p60 (p60-katanin) is a microtubule (MT)-severing enzyme and its activity is regulated by the p80 subunit (adaptor-p80). p60-katanin consists of an N-terminal domain, followed by a single ATPase associated with various cellular activities (AAA) domain. We have previously shown that the N-terminal domain serves as the binding site for MT, the substrate of p60-katanin. In this study, we show that the same domain shares another interface with the C-terminal domain of adaptor-p80. We further show that Ca2+ ions inhibit the MT-severing activity of p60-katanin, whereas the MT-binding activity is preserved in the presence of Ca2+. In detail, the basal ATPase activity of p60-katanin is stimulated twofold by both MTs and the C-terminal domain of adaptor-p80, whereas Ca2+ reduces elevated ATPase activity to the basal level. We identify the Ca2+-binding site at the end of helix 2 of the N-terminal domain, which is different from the MT-binding interface. On the basis of these observations, we propose a speculative model in which spatial rearrangement of the N-terminal domain relative to the C-terminal AAA domain may be important for productive ATP hydrolysis towards MT-severing. Our model can explain how Ca2+ regulates both severing and ATP hydrolysis activity, because the Ca2+-binding site on the N-terminal domain moves close to the AAA domain during MT severing.
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