In animal cell cytokinesis, interaction of non-muscle myosin II (NMII) with F-actin provides the dominant force for pinching the mother cell into two daughters. Here we demonstrate that celibe (cbe) is a missense allele of zipper, which encodes the Drosophila Myosin heavy chain. Mutation of cbe impairs binding of Zipper protein to the regulatory light chain Spaghetti squash (Sqh). In dividing spermatocytes from cbe males, Sqh fails to concentrate at the equatorial cortex, resulting in thin actomyosin rings that are unable to constrict. We show that cbe mutation impairs localization of the phosphatidylinositol 4-phosphate [PI(4)P]-binding protein Golgi phosphoprotein 3 (GOLPH3, also known as Sauron) and maintenance of centralspindlin at the cell equator of telophase cells. Our results further demonstrate that GOLPH3 protein associates with Sqh and directly binds the centralspindlin subunit Pavarotti. We propose that during cytokinesis, the reciprocal dependence between Myosin and PI(4)P–GOLPH3 regulates centralspindlin stabilization at the invaginating plasma membrane and contractile ring assembly.

在动物细胞胞质分裂中，非肌肉肌球蛋白 II (NMII) 与 F-肌动蛋白的相互作用提供了将母细胞挤压成两个子细胞的主导力。在这里，我们证明celibe ( cbe ) 是zipper的错义等位基因，编码果蝇肌球蛋白重链。cbe突变会损害 Zipper 蛋白与调节轻链 Spaghetti squash (Sqh) 的结合。在从cbe雄性中分裂精母细胞时，Sqh 无法集中在赤道皮层，导致无法收缩的薄肌动球蛋白环。我们发现，cbe突变会损害磷脂酰肌醇 4-磷酸 [PI(4)P] 结合蛋白高尔基体磷蛋白 3（GOLPH3，也称为 Sauron）的定位以及末期细胞细胞赤道处中枢纺锤蛋白的维持。我们的结果进一步证明 GOLPH3 蛋白与 Sqh 结合并直接结合中枢纺锤体亚基帕瓦罗蒂。我们提出，在胞质分裂过程中，肌球蛋白和 PI(4)P-GOLPH3 之间的相互依赖性调节内陷质膜和收缩环组件的中枢纺锤体稳定性。