Evidence for cooperative interactions between the two motor domains of cytoplasmic dynein.
Evidence for cooperative interactions between the two motor domains of cytoplasmic dynein.
复制标题
细胞质动力蛋白的两个运动域之间合作相互作用的证据。
DOI：
10.1016/s0960-9822(99)80340-6
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Hays,TS
中科院分区：
文献类型：
--
作者：
Iyadurai,SJ;Li,MG;Gilbert,SP;Hays,TS
细胞质动力蛋白是一种力传递ATP酶，为细胞内物质沿沿着运动提供动力。细胞质动力蛋白复合物的两个相同的重链多肽（> 500 kDa）含有马达结构域，其具有力产生所需的ATP酶和微管结合活性[1]。这是非常感兴趣的，以确定是否在动力蛋白复合物的重链（DHCs）所需的机械化学循环和运动的进展，如观察到的其他二聚马达。我们使用转基因构建体来研究果蝇胞质动力蛋白复合体的两个运动域之间的协同相互作用。我们发现，138 kDa和180 kDa的DHC的氨基末端片段可以组装与全长DHC形成异二聚体复合物，只包含一个单一的电机域。单头动力蛋白复合物可以结合和水解ATP，但不显示ATP诱导的从微管的分离，这是野生型同型二聚体动力蛋白的特征。这些结果表明，二聚体的单体单元之间的合作相互作用是必需的有效ATP诱导的动力蛋白的分离和单向运动沿着微管。
Cytoplasmic dynein is a force-transducing ATPase that powers the movement of cellular cargoes along microtubules. Two identical heavy chain polypeptides (> 500 kDa) of the cytoplasmic dynein complex contain motor domains that possess the ATPase and microtubule-binding activities required for force production [1]. It is of great interest to determine whether both heavy chains (DHCs) in the dynein complex are required for progression of the mechanochemical cycle and motility, as observed for other dimeric motors. We have used transgenic constructs to investigate cooperative interactions between the two motor domains of theDrosophilacytoplasmic dynein complex. We show that 138 kDa and 180 kDa amino-terminal fragments of DHC can assemble with full-length DHC to form heterodimeric complexes containing only a single motor domain. The single-headed dynein complexes can bind and hydrolyze ATP, yet do not show the ATP-induced detachment from microtubules that is characteristic of wild-type homodimeric dynein. These results suggest that cooperative interactions between the monomeric units of the dimer are required for efficient ATP-induced detachment of dynein and unidirectional movement along the microtubule.