Togo Tatsuru
Misaki Marine Biological Station, University of Tokyo, 1024 Ko-Ajiro, Misaki, Miura, Kanagawa 238-0225, Japan.
J Cell Sci. 2006 Jul 1;119(Pt 13):2780-6. doi: 10.1242/jcs.03006. Epub 2006 Jun 13.
Resealing of a disrupted plasma membrane requires Ca(2+)-regulated exocytosis. Repeated disruptions reseal more quickly than the initial wound. This facilitated response requires both Ca(2+) and protein kinase C (PKC), and is sensitive to brefeldin A. There is also evidence that this response is polarized to the site where the cell membrane had previously been disrupted. Observations of GFP-tagged alpha-tubulin and end-binding protein 1 (EB1) revealed that membrane disruption initially induced disassembly of microtubules around the wound site, followed by elongation of microtubules toward the wound site. Recruitment of EB1 to microtubules required Ca(2+) influx, but was independent of PKC. NBD C(6)-ceramide, a probe for the Golgi apparatus and Golgi-derived lipids, initially stained the perinuclear region, and a portion of the probe was translocated to the wound site 5 minutes after wounding. Translocation of the lipids required microtubules and PKC activity, and was suppressed by low temperature. On the other hand, constitutive traffic of the lipid was still normal in the presence of a PKC inhibitor. These findings suggest that membrane disruption stimulates regulated vesicle traffic from the region of the trans-Golgi network to the wound site along rearranged microtubules in a PKC-dependent manner.
破裂的质膜重新封闭需要Ca(2+)调节的胞吐作用。重复破裂比初始伤口重新封闭得更快。这种促进反应既需要Ca(2+)也需要蛋白激酶C（PKC），并且对布雷菲德菌素A敏感。也有证据表明这种反应在细胞膜先前破裂的部位极化。对绿色荧光蛋白标记的α-微管蛋白和微管末端结合蛋白1（EB1）的观察表明，膜破裂最初诱导伤口部位周围的微管解聚，随后微管向伤口部位延伸。EB1募集到微管需要Ca(2+)内流，但与PKC无关。NBD C(6)-神经酰胺是一种用于高尔基体和高尔基体衍生脂质的探针，最初染色核周区域，一部分探针在受伤5分钟后转运到伤口部位。脂质的转运需要微管和PKC活性，并且受低温抑制。另一方面，在PKC抑制剂存在的情况下，脂质的组成型运输仍然正常。这些发现表明，膜破裂以PKC依赖的方式刺激从反式高尔基体网络区域沿着重新排列的微管向伤口部位的调节性囊泡运输。
