Charette Steve J, Cosson Pierre
Université de Genève, Centre Médical Universitaire, Département de physiologie cellulaire et métabolisme, 1 rue Michel Servet, CH-1211 Geneva 4, Switzerland.
FEBS Lett. 2006 Sep 4;580(20):4923-8. doi: 10.1016/j.febslet.2006.08.009. Epub 2006 Aug 15.
Exocytosis of late endocytic compartments in Dictyostelium has mostly been studied by live microscopy. Here we show that this exocytosis is accompanied by a complete fusion of late endosomes with the plasma membrane resulting in the transient formation of membrane microdomains that can be visualized by immunofluorescence in fixed cells. This permitted to demonstrate that fusion of late endocytic compartments with the cell surface does not occur in regions of the plasma membrane engaged in the formation of pseudopods, macropinosomes or phagosomes. Our results propose that exocytosis of late endosomes and actin-driven membrane remodeling are mutually exclusive processes.
在盘基网柄菌中，晚期内吞区室的胞吐作用大多是通过活细胞显微镜观察进行研究的。我们在此表明，这种胞吐作用伴随着晚期内体与质膜的完全融合，导致膜微区的短暂形成，这在固定细胞中可通过免疫荧光观察到。这使得我们能够证明，晚期内吞区室与细胞表面的融合不会发生在参与伪足、巨胞饮体或吞噬体形成的质膜区域。我们的结果表明，晚期内体的胞吐作用和肌动蛋白驱动的膜重塑是相互排斥的过程。
