The terminal tail region of a yeast myosin-V mediates its attachment to vacuole membranes and sites of polarized growth
The terminal tail region of a yeast myosin-V mediates its attachment to vacuole membranes and sites of polarized growth
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DOI：
10.1073/pnas.95.25.14799
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发表时间：
1998-12-08
影响因子：
11.1
通讯作者：
Weisman, LS
中科院分区：
文献类型：
--
作者：
Catlett, NL;Weisman, LS
酿酒酵母肌球蛋白-V，Myo 2 p，已被牵连在几个细胞器的极化运动，是必不可少的酵母活力。我们以前已经表明，Myo 2 p是必需的溶酶体（液泡）的一部分进入芽的运动，因此在细胞分裂过程中，这个细胞器的适当继承。V类肌球蛋白有一个球状羧基末端尾部结构域，可能通过与细胞器特异性受体的相互作用介导肌球蛋白的定位。在这里，我们描述了一个myo 2等位基因，其表型支持这一假设。vac 15 -1/myo 2 -2在该球状尾结构域中具有单一突变，导致空泡运动和遗传缺陷。虽然野生型Myo 2 p的一部分与液泡分离，myo 2 -2基因产物不。此外，突变蛋白不集中在活跃生长的位点，野生型Myo 2 p的主要位置。虽然尾部结构域的缺失是致命的，但myo 2 -2基因产物保留了Myo 2 p的基本功能。此外，myo 2 -2不会引起生长缺陷和致命的遗传相互作用中看到的mgo 2 -66，在肌动蛋白结合域的突变缺陷。这些观察结果表明，myo 2 -2突变特异性地破坏与选定的肌球蛋白受体的相互作用，即那些在液泡膜上和那些在极化生长的网站。
The Saccharomyces cerevisiae myosin-V, Myo2p, has been implicated in the polarized movement of several organelles and is essential for yeast viability. We have shown previously that Myo2p is required for the movement of a portion of the lysosome (vacuole) into the bud and consequently for proper inheritance of this organelle during cell division. Class V myosins have a globular carboxyl terminal tail domain that is proposed to mediate localization of the myosin, possibly through interaction with organelle-specific receptors. Here we describe a myo2 allele whose phenotypes support this hypothesis. vac15-1/myo2-2 has a single mutation in this globular tail domain, causing defects in vacuole movement and inheritance. Although a portion of wild-type Myo2p fractionates with the vacuole, the myo2-2 gene product does not. In addition, the mutant protein does not concentrate at sites of active growth, the predominant location of wild-type Myo2p. Although deletion of the tail domain is lethal, the myo2-2 gene product retains the essential functions of Myo2p. Moreover, myo2-2 does not cause the growth defects and lethal genetic interactions seen in mgo2-66, a mutant defective in the actin-binding domain. These observations suggest that the myo2-2 mutation specifically disrupts interactions with selected myosin receptors, namely those on the vacuole membrane and those at sites of polarized growth.