Motility of myosin V regulated by the dissociation of single calmodulin
Motility of myosin V regulated by the dissociation of single calmodulin
复制标题
DOI：
10.1038/nsmb894
复制
发表时间：
2005-02-01
影响因子：
16.8
通讯作者：
Higuchi, H
中科院分区：
文献类型：
--
作者：
Nguyen, H;Higuchi, H
肌球蛋白V是一种钙调蛋白结合的马达蛋白。在1 μ M Ca2+时，单个钙调素分子从单个肌球蛋白V分子中解离与体外运动性测定中滑动速度的降低相关。两个钙调素分子在5 μ M Ca2+的解离与肌动蛋白丝从肌球蛋白V的分离相关。为了模拟细胞中Ca2+对肌球蛋白V运动性的调节，使用笼状Ca2+与UV闪光系统耦合来产生Ca2+瞬变。在钙瞬变过程中，肌球蛋白V经历了滑动速度降低、肌动蛋白脱离和重新附着，然后滑动速度恢复的功能循环。这些结果表明，肌球蛋白V的运动性是由钙离子通过减少肌动蛋白结合亲和力导致的单个钙调素分子的解离调节。
Myosin V is a calmodulin-binding motor protein. The dissociation of single calmodulin molecules from individual myosin V molecules at 1 muM Ca2+ correlates with a reduction in sliding velocity in an in vitro motility assay. The dissociation of two calmodulin molecules at 5 muM Ca2+ correlates with a detachment of actin filaments from myosin V. To mimic the regulation of myosin V motility by Ca2+ in a cell, caged Ca2+ coupled with a UV flash system was used to produce Ca2+ transients. During the Ca2+ transient, myosin V goes through the functional cycle of reduced sliding velocity, actin detachment and reattachment followed by the recovery of the sliding velocity. These results indicate that myosin V motility is regulated by Ca2+ through a reduction in actin-binding affinity resulting from the dissociation of single calmodulin molecules.