Wahlström G, Vartiainen M, Yamamoto L, Mattila P K, Lappalainen P, Heino T I
Developmental Biology Program, Institute of Biotechnology, Viikki Biocenter, FIN-00014 University of Helsinki, Finland.
J Cell Biol. 2001 Nov 26;155(5):787-96. doi: 10.1083/jcb.200108022.
The actin cytoskeleton is essential for cellular remodeling and many developmental and morphological processes. Twinfilin is a ubiquitous actin monomer-binding protein whose biological function has remained unclear. We discovered and cloned the Drosophila twinfilin homologue, and show that this protein is ubiquitously expressed in different tissues and developmental stages. A mutation in the twf gene leads to a number of developmental defects, including aberrant bristle morphology. This results from uncontrolled polymerization of actin filaments and misorientation of actin bundles in developing bristles. In wild-type bristles, twinfilin localizes diffusively to cytoplasm and to the ends of actin bundles, and may therefore be involved in localization of actin monomers in cells. We also show that twinfilin and the ADF/cofilin encoding gene twinstar interact genetically in bristle morphogenesis. These results demonstrate that the accurate regulation of size and dynamics of the actin monomer pool by twinfilin is essential for a number of actin-dependent developmental processes in multicellular eukaryotes.
肌动蛋白细胞骨架对于细胞重塑以及许多发育和形态过程至关重要。双丝蛋白是一种普遍存在的肌动蛋白单体结合蛋白，其生物学功能尚不清楚。我们发现并克隆了果蝇双丝蛋白同源物，表明该蛋白在不同组织和发育阶段普遍表达。twf基因的突变会导致许多发育缺陷，包括刚毛形态异常。这是由于发育中的刚毛中肌动蛋白丝不受控制的聚合以及肌动蛋白束的方向错误所致。在野生型刚毛中，双丝蛋白分散地定位于细胞质和肌动蛋白束的末端，因此可能参与细胞中肌动蛋白单体的定位。我们还表明，双丝蛋白与编码ADF/丝切蛋白的基因双星在刚毛形态发生中存在遗传相互作用。这些结果表明，双丝蛋白对肌动蛋白单体池大小和动态的精确调节对于多细胞真核生物中许多依赖肌动蛋白的发育过程至关重要。
