The recruitment of acetylated and unacetylated tropomyosin to distinct actin polymers permits the discrete regulation of specific myosins in fission yeast
The recruitment of acetylated and unacetylated tropomyosin to distinct actin polymers permits the discrete regulation of specific myosins in fission yeast
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DOI：
10.1242/jcs.069971
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发表时间：
2010-10-01
影响因子：
4
通讯作者：
Mulvihill, Daniel P.
中科院分区：
文献类型：
--
作者：
Coulton, Arthur T.;East, Daniel A.;Mulvihill, Daniel P.
原肌球蛋白（Tm）是一种保守的二聚体卷曲蛋白，其形成的聚合物卷曲在肌动蛋白丝周围，以调节肌动球蛋白的功能。Tm n端蛋氨酸的乙酰化增强了端到端键，从而增强了肌动蛋白的结合以及Tm调节肌肉和非肌肉细胞中肌球蛋白运动活性的能力。在这项研究中，我们探讨了每个Tm形式在裂变酵母细胞中的功能。电子显微镜和活细胞成像显示，乙酰化和未乙酰化的Tm与细胞内不同的肌动蛋白结构相关，每种形式对聚合肌动蛋白丝的形状和完整性都有深远的影响。我们发现，虽然Tm乙酰化是调节II类肌球蛋白体内运动所必需的，但乙酰化的Tm对I类和V类肌球蛋白的运动没有影响。这些发现说明了一种新的tm -乙酰化状态依赖机制来调节特定的肌动球蛋白细胞骨架相互作用。
Tropomyosin (Tm) is a conserved dimeric coiled-coil protein, which forms polymers that curl around actin filaments in order to regulate actomyosin function. Acetylation of the Tm N-terminal methionine strengthens end-to-end bonds, which enhances actin binding as well as the ability of Tm to regulate myosin motor activity in both muscle and non-muscle cells. In this study we explore the function of each Tm form within fission yeast cells. Electron microscopy and live cell imaging revealed that acetylated and unacetylated Tm associate with distinct actin structures within the cell, and that each form has a profound effect upon the shape and integrity of the polymeric actin filament. We show that, whereas Tm acetylation is required to regulate the in vivo motility of class II myosins, acetylated Tm had no effect on the motility of class I and V myosins. These findings illustrate a novel Tm-acetylation-state-dependent mechanism for regulating specific actomyosin cytoskeletal interactions.