Glowinski Cory, Liu Ri-Hua Sandy, Chen Xi, Darabie Audrey, Godt Dorothea
Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON, M5S 2M6, Canada.
Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON, M5S 2M6, Canada
J Cell Sci. 2014 Nov 15;127(Pt 22):4821-32. doi: 10.1242/jcs.099242. Epub 2014 Sep 18.
Microvilli and related actin-based protrusions permit multiple interactions between cells and their environment. How the shape, length and arrangement of microvilli are determined remains largely unclear. To address this issue and explore the cooperation of the two main components of a microvillus, the central F-actin bundle and the enveloping plasma membrane, we investigated the expression and function of Myosin VIIA (Myo7A), which is encoded by crinkled (ck), and its interaction with cadherin Cad99C in the microvilli of the Drosophila follicular epithelium. Myo7A is present in the microvilli and terminal web of follicle cells, and associates with several other F-actin-rich structures in the ovary. Loss of Myo7A caused brush border defects and a reduction in the amount of the microvillus regulator Cad99C. We show that Myo7A and Cad99C form a molecular complex and that the cytoplasmic tail of Cad99C recruits Myo7A to microvilli. Our data indicate that Myo7A regulates the structure and spacing of microvilli, and interacts with Cad99C in vivo. A comparison of the mutant phenotypes suggests that Myo7A and Cad99C have co-dependent and independent functions in microvilli.
微绒毛及相关的基于肌动蛋白的突起允许细胞与其环境之间进行多种相互作用。微绒毛的形状、长度和排列是如何确定的，目前仍不清楚。为了解决这个问题并探索微绒毛的两个主要组成部分——中央F-肌动蛋白束和包被的质膜之间的协作，我们研究了由皱缩基因（ck）编码的肌球蛋白VIIA（Myo7A）的表达和功能，以及它在果蝇卵泡上皮微绒毛中与钙黏蛋白Cad99C的相互作用。Myo7A存在于卵泡细胞的微绒毛和终末网中，并与卵巢中其他几个富含F-肌动蛋白的结构相关联。Myo7A的缺失导致刷状缘缺陷以及微绒毛调节因子Cad99C的量减少。我们发现Myo7A和Cad99C形成了一个分子复合物，并且Cad99C的细胞质尾巴将Myo7A招募到微绒毛上。我们的数据表明，Myo7A调节微绒毛的结构和间距，并在体内与Cad99C相互作用。对突变体表型的比较表明，Myo7A和Cad99C在微绒毛中具有相互依赖和独立的功能。
