Disruption of the plasma membrane stimulates rearrangement of microtubules and lipid traffic toward the wound site

Abstract

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.