کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2130726 1086597 2012 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
RIM, Munc13, and Rab3A interplay in acrosomal exocytosis
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی تحقیقات سرطان
پیش نمایش صفحه اول مقاله
RIM, Munc13, and Rab3A interplay in acrosomal exocytosis
چکیده انگلیسی

Exocytosis is a highly regulated, multistage process consisting of multiple functionally definable stages, including recruitment, targeting, tethering, priming, and docking of secretory vesicles with the plasma membrane, followed by calcium-triggered membrane fusion. The acrosome reaction of spermatozoa is a complex, calcium-dependent regulated exocytosis. Fusion at multiple sites between the outer acrosomal membrane and the cell membrane causes the release of the acrosomal contents and the loss of the membranes surrounding the acrosome. Not much is known about the molecules that mediate membrane docking in this particular fusion model. In neurons, the formation of the ternary RIM/Munc13/Rab3A complex has been suggested as a critical component of synaptic vesicles docking. Previously, we demonstrated that Rab3A localizes to the acrosomal region in human sperm, stimulates acrosomal exocytosis, and participates in an early stage during membrane fusion. Here, we report that RIM and Munc13 are also present in human sperm and localize to the acrosomal region. Like Rab3A, RIM and Munc13 participate in a prefusion step before the efflux of intra-acrosomal calcium. By means of a functional assay using antibodies and recombinant proteins, we show that RIM, Munc13 and Rab3A interplay during acrosomal exocytosis. Finally, we report by electron transmission microscopy that sequestering RIM and Rab3A alters the docking of the acrosomal membrane to the plasma membrane during calcium-activated acrosomal exocytosis. Our results suggest that the RIM/Munc13/Rab3 A complex participates in acrosomal exocytosis and that RIM and Rab3A have central roles in membrane docking.


► RIM and Munc13 are present in human sperm and localize to the acrosomal region.
► RIM and Munc13 are necessary for acrosomal exocytosis.
► RIM and Munc13 participate before the acrosomal calcium efflux.
► RIM, Munc13 and Rab3A interplay in human sperm acrosomal exocytosis.
► RIM and Rab3A have critical roles in membrane docking.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Experimental Cell Research - Volume 318, Issue 5, 10 March 2012, Pages 478–488
نویسندگان
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