A formin homology protein and a profilin are required for cytokinesis and Arp2/3-independent assembly of cortical microfilaments in C-elegans
A formin homology protein and a profilin are required for cytokinesis and Arp2/3-independent assembly of cortical microfilaments in C-elegans
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DOI：
10.1016/s0960-9822(02)01355-6
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发表时间：
2002-12-23
期刊：
影响因子：
9.2
通讯作者：
Bowerman, B
中科院分区：
文献类型：
--
作者：
Severson, AF;Baillie, DL;Bowerman, B
背景：秀丽隐杆线虫胚胎细胞皮层富含f -肌动蛋白，在包括前后轴（A-P）的建立和细胞分裂在内的多个过程中都是必需的。然而，调节皮质微丝（MF）组装的机制仍然知之甚少。结果：我们在这里表明，一种称为PFN-1的谱蛋白在皮层独立于肌动蛋白细胞骨架积累，是皮层mf和肌球蛋白组装或维持所必需的。通过RNAi降低PFN-1水平导致细胞分裂和A-P极性缺陷。PFN-1结合双胍蛋白同源性（FH）蛋白CYK-1，这也是皮质MFs所必需的。与PFN-1和CYK-1相比，Arp2/3复合物对于皮质mf的组装、A-P极性和细胞分裂似乎是必不可少的。相反，Arp2/3复合体是发生在原肠胚形成过程中的细胞迁移所必需的，也可能参与卵形胚胎伸长成蚓状幼虫之前表皮围合所需的细胞重排。结论：我们认为FH蛋白CYK-1和PFN-1介导了早期胚胎中MFs的arp2 /3独立组装，并且是细胞分裂所必需的。这些数据表明CYK-1和PFN-1可能形成MFs，正如最近在酵母中的FH蛋白和谱中所显示的那样。
Background: F-actin is enriched at the cortex of embryonic cells in the nematode Caenorhabditis elegans and is required for multiple processes that include the establishment of an anterior-posterior (A-P) axis and cytokinesis. However, the mechanisms that regulate cortical microfilament (MF) assembly remain poorly understood.Results: We show here that a profilin called PFN-1 accumulates at the cortex independent of the actin cytoskeleton and is required for the assembly or maintenance of cortical MFs and myosin. Reducing PFN-1 levels by RNAi results in cytokinesis and A-P polarity defects. PFN-1 binds to the Formin Homology (FH) protein CYK-1, which also is required for cortical MFs. In contrast to PFN-1 and CYK-1, the Arp2/3 complex appears to be dispensable for the assembly of cortical MFs, for A-P polarity, and for cytokinesis. Instead, the Arp2/3 complex is required for cell migrations that occur during gastrulation and may also be involved in cellular rearrangements required for epidermal enclosure prior to elongation of ovoid embryos into vermiform larvae. Conclusions: We conclude that the FH protein CYK-1 and the profilin PFN-1 mediate the Arp2/3-independent assembly of MFs and are required for cytokinesis in the early embryo. These data suggest that CYK-1 and PFN-1 may nucleate MFs, as has recently been shown for an FH protein and a profilin in yeast.