期刊
BIOPHYSICAL JOURNAL
卷 106, 期 3, 页码 649-658出版社
CELL PRESS
DOI: 10.1016/j.bpj.2013.12.038
关键词
-
类别
资金
- American Heart Association (AHA) predoctoral fellowship
- AHA [12GRNT12050314]
- VUMC Digestive Diseases Research Center [DK058404]
- Vanderbilt University IDEAS award
- National Institutes of Health [DK075555, DK095811]
- National Science Foundation [0970008]
- Vanderbilt Diabetes Research and Training Center
- National Institute of Diabetes and Digestive and Kidney Disease [DK020593]
- Division Of Mathematical Sciences
- Direct For Mathematical & Physical Scien [0970008] Funding Source: National Science Foundation
Class 1 myosins are monomeric motor proteins that fulfill diverse functions at the membrane/cytoskeletal interface. All myosins-1 contain a motor domain, which binds actin, hydrolyzes ATP, and generates forces, and a TH1 domain, which interacts directly with membrane lipids. In most cases, TH1 is needed for proper subcellular localization and presumably function, although little is known about how this domain regulates the behavior of class 1 myosins in live cells. To address this, we used single molecule total internal reflection fluorescence microscopy to examine the dynamics of the well-characterized myosin-1a isoform during interactions with the cortex of living cells. Our studies revealed that full-length myosin-1a exhibits restricted mobility relative to TH1 alone. Motor domain mutations that disrupt actin binding increased the mobility of full-length myosin-1a, whereas mutations to the TH1 domain that are known to reduce steady-state targeting to the plasma membrane unexpectedly reduced mobility. Deletion of the calmodulin-binding lever arm in Myo 1a mimicked the impact of actin-binding mutations. Finally, myosin-1b, which demonstrates exquisite sensitivity to mechanical load, exhibited dynamic behavior nearly identical to myosin-1a. These studies are the first, to our knowledge, to explore class 1 myosin dynamics at the single-molecule level in living cells; our results suggest a model where the motor domain restricts dynamics via a mechanism that requires the lever arm, whereas the TH1 domain allows persistent diffusion in close proximity to the plasma membrane.
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