Motor function of unconventional myosin.
Motor function of unconventional myosin.
复制标题
DOI：
10.1007/978-1-4419-9029-7_13
复制
发表时间：
2003
影响因子：
--
通讯作者：
M. Ikebe;Akira Inoue;S. Nishikawa;K. Homma;Hiroto Tanaka;A. Iwane;E. Katayama;R. Ikebe;T. Yanagida
中科院分区：
文献类型：
--
作者：
M. Ikebe;Akira Inoue;S. Nishikawa;K. Homma;Hiroto Tanaka;A. Iwane;E. Katayama;R. Ikebe;T. Yanagida
肌球蛋白是与肌动蛋白丝相互作用并将ATP水解产生的能量转化为机械力的马达蛋白。除了肌肉和非肌肉细胞中典型的双头肌球蛋白II外，最近还发现了许多肌球蛋白样蛋白。根据它们的氨基酸序列，这些新发现的“肌球蛋白”似乎不会形成肌球蛋白丝，因此它们通常被称为“非常规”肌球蛋白。这些肌球蛋白样运动蛋白的发现从根本上扩展了肌球蛋白在各种生物过程中的潜在生理重要性，如趋化运动、内吞作用、胞吐作用、吞噬作用、囊泡运输、分泌等。（切尼等人，1993; Goodson和Spudich，1993; Mooseker和切尼，1995;科普等人，1996; Titus，1997; Hodge和科普，2000），并分为至少18类。在脊椎动物中，已经表明表达了11类肌球蛋白（包括常规的肌丝形成肌球蛋白）。这些类别的非常规肌球蛋白的N-末端结构域是相对保守的，并且包含主要的力产生机制，而C-末端尾部结构域是高度发散的，并且被认为作为与细胞伴侣分子结合的靶向位点起作用。在肌球蛋白的马达和不同尾部结构域之间，存在由不同数量的轻链结合基序组成的颈区（Mermall et al，1998）。
Myosins are motor proteins that interact with actin filaments and convert energy from ATP hydrolysis into mechanical force. In addition to the well-characterized conventional, filament forming, two-headed myosin II of muscle and non-muscle cells, a number of myosin-like proteins have recently been discovered. Based upon their amino acid sequences, these newly found “myosins” do not seem to form myosin filaments, thus they are often called “unconventional” myosins. The discovery of these “myosin-like motor proteins” has fundamentally expanded the potential physiological importance of myosins in diverse biological processes such as chemotactic motility, endocytosis, exocytosis, phagocytosis, vesicular trafficking, secretion, etc. The myosins are classified based upon phylogenetie sequence comparisons of the motor domain (Cheney et al, 1993; Goodson and Spudich, 1993; Mooseker and Cheney, 1995; Cope et al, 1996; Titus, 1997; Hodge and Cope, 2000) and divided into at least 18 classes. In vertebrates, it has been shown that eleven classes of myosin,(including conventional filament forming myosin) are expressed. The N-terminal domains of these classes of unconventional myosins are relatively conserved and contain the primary force production machinery, whereas the C-terminal tail domains are highly divergent and are thought to function as targeting sites that bind to the cellular partner molecules. Between the motor and the diverse tail domains of myosin, there are neck regions that are composed of various numbers of light chain binding motifs (Mermall et al, 1998).