Swan K A, Severson A F, Carter J C, Martin P R, Schnabel H, Schnabel R, Bowerman B
Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA.
J Cell Sci. 1998 Jul 30;111 ( Pt 14):2017-27. doi: 10.1242/jcs.111.14.2017.
A maternally expressed Caenorhabditis elegans gene called cyk-1 is required for polar body extrusion during meiosis and for a late step in cytokinesis during embryonic mitosis. Other microfilament- and microtubule-dependent processes appear normal in cyk-1 mutant embryos, indicating that cyk-1 regulates a specific subset of cytoskeletal functions. Because cytokinesis initiates normally and cleavage furrows ingress extensively in cyk-1 mutant embryos, we propose that the wild-type cyk-1 gene is required for a late step in cytokinesis. Cleavage furrows regress after completion of mitosis in cyk-1 mutants, leaving multiple nuclei in a single cell. Positional cloning and sequence analysis of the cyk-1 gene reveal that it encodes an FH protein, a newly defined family of proteins that appear to interact with the cytoskeleton during cytokinesis and in the regulation of cell polarity. Consistent with cyk-1 function being required for a late step in embryonic cytokinesis, we show that the CYK-1 protein co-localizes with actin microfilaments as a ring at the leading edge of the cleavage furrow, but only after extensive furrow ingression. We discuss our findings in the context of other studies suggesting that FH genes in yeast and insects function early in cytokinesis to assemble a cleavage furrow.
一种名为cyk-1的秀丽隐杆线虫母源表达基因，在减数分裂期间的极体挤出以及胚胎有丝分裂期间胞质分裂的后期步骤中是必需的。在cyk-1突变胚胎中，其他微丝和微管依赖的过程看起来正常，这表明cyk-1调节细胞骨架功能的一个特定子集。因为在cyk-1突变胚胎中胞质分裂正常启动且分裂沟广泛内陷，我们提出野生型cyk-1基因是胞质分裂后期步骤所必需的。在cyk-1突变体中，有丝分裂完成后分裂沟退缩，在单个细胞中留下多个细胞核。cyk-1基因的定位克隆和序列分析表明它编码一种FH蛋白，这是一个新定义的蛋白家族，在胞质分裂期间以及细胞极性调节过程中似乎与细胞骨架相互作用。与cyk-1功能是胚胎胞质分裂后期步骤所必需的一致，我们表明CYK-1蛋白与肌动蛋白微丝在分裂沟前缘作为一个环共定位，但仅在广泛的沟内陷之后。我们在其他研究的背景下讨论我们的发现，这些研究表明酵母和昆虫中的FH基因在胞质分裂早期起作用以组装分裂沟。
