The 95F unconventional myosin is required for proper organization of the Drosophila syncytial blastoderm.
The 95F unconventional myosin is required for proper organization of the Drosophila syncytial blastoderm.
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DOI：
10.1083/jcb.129.6.1575
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发表时间：
1995-06
期刊：
影响因子：
--
通讯作者：
Miller KG
中科院分区：
文献类型：
--
作者：
Mermall V;Miller KG
95F肌球蛋白是一种VI类非常规肌球蛋白，与果蝇合胞囊胚细胞质中的颗粒相关，并且是这些颗粒依赖ATP和f -actin的易位所必需的。颗粒经历细胞周期依赖的再分配，从间期围绕每个细胞核的结构域到有丝分裂期间相邻纺锤体之间提供屏障的短暂膜内陷。当抗体注射抑制95F肌球蛋白功能时，合胞囊胚组织发生严重缺陷。这种紊乱被视为异常的核形态和位置，并提示细胞骨架功能的失败。核缺陷与肌动蛋白细胞骨架的严重缺陷相关，包括肌动蛋白帽和沟不明显、肌动蛋白结构缺失、帽间距异常和沟间距异常。注射抗95f肌球蛋白抗体的胚胎三维检查显示肌动蛋白沟不像正常沟那样深入胚胎。这些沟壑不能分离相邻的有丝分裂，因为微管在沟壑上交叉。这些不适当的微管相互作用导致异常的核分裂和观察到的核缺陷。我们提出95F肌球蛋白的功能是产生正常的肌动蛋白瞬时膜沟所必需的。95F肌凝蛋白本身和/或由95F肌凝蛋白运送到沟槽的颗粒内的成分的运动活性可能是形成正常沟槽所必需的。
The 95F myosin, a class VI unconventional myosin, associates with particles in the cytoplasm of the Drosophila syncytial blastoderm and is required for the ATP- and F-actin-dependent translocation of these particles. The particles undergo a cell cycle-dependent redistribution from domains that surround each nucleus in interphase to transient membrane invaginations that provide a barrier between adjacent spindles during mitosis. When 95F myosin function is inhibited by antibody injection, profound defects in syncytial blastoderm organization occur. This disorganization is seen as aberrant nuclear morphology and position and is suggestive of failures in cytoskeletal function. Nuclear defects correlate with gross defects in the actin cytoskeleton, including indistinct actin caps and furrows, missing actin structures, abnormal spacing of caps, and abnormally spaced furrows. Three- dimensional examination of embryos injected with anti-95F myosin antibody reveals that actin furrows do not invaginate as deeply into the embryo as do normal furrows. These furrows do not separate adjacent mitoses, since microtubules cross over them. These inappropriate microtubule interactions lead to aberrant nuclear divisions and to the nuclear defects observed. We propose that 95F myosin function is required to generate normal actin-based transient membrane furrows. The motor activity of 95F myosin itself and/or components within the particles transported to the furrows by 95F myosin may be required for normal furrows to form.