Ren Nan, Charlton Jeannette, Adler Paul N
Biology Department, Institute for Morphogenesis and Regenerative Medicine and Cancer Center, University of Virginia, Charlottesville, VA 22903, USA.
Genetics. 2007 Aug;176(4):2223-34. doi: 10.1534/genetics.107.072959. Epub 2007 Jun 11.
Adult Drosophila are decorated with several types of polarized cuticular structures, such as hairs and bristles. The morphogenesis of these takes place in pupal cells and is mediated by the actin and microtubule cytoskeletons. Mutations in flare (flr) result in grossly abnormal epidermal hairs. We report here that flr encodes the Drosophila actin interacting protein 1 (AIP1). In other systems this protein has been found to promote cofilin-mediated F-actin disassembly. In Drosophila cofilin is encoded by twinstar (tsr). We show that flr mutations result in increased levels of F-actin accumulation and increased F-actin stability in vivo. Further, flr is essential for cell proliferation and viability and for the function of the frizzled planar cell polarity system. All of these phenotypes are similar to those seen for tsr mutations. This differs from the situation in yeast where cofilin is essential while aip1 mutations result in only subtle defects in the actin cytoskeleton. Surprisingly, we found that mutations in flr and tsr also result in greatly increased tubulin staining, suggesting a tight linkage between the actin and microtubule cytoskeleton in these cells.
成年果蝇体表有多种类型的极化表皮结构，如刚毛和鬃毛。这些结构的形态发生在蛹期细胞中，并由肌动蛋白和微管细胞骨架介导。flare（flr）基因的突变会导致表皮刚毛严重异常。我们在此报告，flr编码果蝇肌动蛋白相互作用蛋白1（AIP1）。在其他系统中，已发现该蛋白可促进cofilin介导的F-肌动蛋白解聚。在果蝇中，cofilin由twinstar（tsr）编码。我们发现，flr突变会导致体内F-肌动蛋白积累水平增加以及F-肌动蛋白稳定性增强。此外，flr对于细胞增殖和活力以及卷曲蛋白平面细胞极性系统的功能至关重要。所有这些表型都与tsr突变所观察到的相似。这与酵母中的情况不同，在酵母中cofilin是必需的，而aip1突变仅导致肌动蛋白细胞骨架出现细微缺陷。令人惊讶的是，我们发现flr和tsr的突变还会导致微管染色显著增加，表明这些细胞中肌动蛋白和微管细胞骨架之间存在紧密联系。
