The yeast class V myosins, Myo2p and Myo4p, are nonprocessive actin-based motors.
The yeast class V myosins, Myo2p and Myo4p, are nonprocessive actin-based motors.
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DOI：
10.1083/jcb.153.5.1121
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发表时间：
2001-05-28
影响因子：
7.8
通讯作者：
Mooseker, M S
中科院分区：
文献类型：
--
作者：
Reck-Peterson, S L;Tyska, M J;Novick, P J;Mooseker, M S
用体外运动学方法研究了酵母V类肌球蛋白Myo2p和Myo4p的运动特性。两种肌球蛋白均为主动运动，Myo2p和Myo4p的最大运动速度分别为4.5μm/S和1.1μm/S。Myo2p运动对钙离子不敏感。这两种肌球蛋白都具有非进行性马达的特性，不像鸡肌球蛋白-Va(M5A)，后者在相同条件下检测时表现为进行性马达。对Myo2p是非进行性马达这一观点的另外支持来自肌动蛋白共构建分析，这些分析表明，与鸡脑M5A不同，Myo2p在ATP和钙离子存在的情况下对F-肌动蛋白的亲和力较低。这些研究表明，如果Myo2p在细胞器运输中起作用，每个细胞器必须至少存在五个Myo2p分子才能促进定向运动。
The motor properties of the two yeast class V myosins, Myo2p and Myo4p, were examined using in vitro motility assays. Both myosins are active motors with maximum velocities of 4.5 μm/s for Myo2p and 1.1 μm/s for Myo4p. Myo2p motility is Ca2+ insensitive. Both myosins have properties of a nonprocessive motor, unlike chick myosin-Va (M5a), which behaves as a processive motor when assayed under identical conditions. Additional support for the idea that Myo2p is a nonprocessive motor comes from actin cosedimentation assays, which show that Myo2p has a low affinity for F-actin in the presence of ATP and Ca2+, unlike chick brain M5a. These studies suggest that if Myo2p functions in organelle transport, at least five molecules of Myo2p must be present per organelle to promote directed movement.