SNAP23 is required for the maintenance of meiotic arrest and cortical granule exocytosis in mouse oocytes

Abstract

Mammalian oocytes are stored in the ovary for prolonged periods, arrested in meiotic prophase. During this period, their plasma membranes are constantly being recycled by endocytosis and exocytosis.However, the function of this membrane turnover is unknown. Here, we investigated the requirement for exocytosis in the maintenance of meiotic arrest. Using Trim-away, a newly developed method for rapidly and specifically depleting proteins in oocytes, we have identified the SNARE protein, SNAP23, to be required for meiotic arrest. Degradation of SNAP23 causes premature meiotic resumption in follicle-enclosed oocytes. The reduction in SNAP23 is associated with loss of gap junction communication between the oocyte and surrounding follicle cells. Reduction of SNAP23 protein also inhibits regulated exocytosis in response to a Ca 2+ stimulus (cortical granule exocytosis), as measured by lectin staining and cleavage of ZP2. Our results show an essential role for SNAP23 in two key processes that occur in mouse oocytes and eggs.

TRIM21—From Intracellular Immunity to Therapy

“…Depletion of NLRP3 was also shown to functionally alter the macrophages, making them resistant to pyroptosis and reducing their release of potent inflammatory cytokine IL-1β (21,91). TRIM-Away has further been used to demonstrate involvement of SNAP23 in meiotic arrest and regulation of exocytosis in developing mouse eggs (92). The usefulness of TRIM-Away to manipulate primary cells is highlighted by the fact that other approaches, such as transfection or transduction of RNA or DNA, are inefficient and stimulate innate signaling (93,94).…”