A mouse acrosomal cortical, matrix protein, MC41, has ZP2-binding activity and forms a complex with a 75-kDa serine protease
A mouse acrosomal cortical, matrix protein, MC41, has ZP2-binding activity and forms a complex with a 75-kDa serine protease
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DOI：
10.1006/dbio.2001.0380
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发表时间：
2001-10-15
影响因子：
2.7
通讯作者：
Toshimori, K
中科院分区：
文献类型：
--
作者：
Tanii, I;Oh-oka, T;Toshimori, K
具有大顶体（如豚鼠和仓鼠）的精子在前顶体中具有亚结构域结构，但小鼠顶体看起来是均匀的，其基质尚未得到精确分析。顶体内蛋白MC41定位于小鼠前顶体皮质区，提示小鼠顶体存在亚结构域结构。因此，本研究采用抗mc41抗体对小鼠顶体基质进行分析。当小鼠精子用2% Triton X-100处理时，Triton不溶性基质成分保留在顶体皮质区。MC41的免疫金标记了Triton X-100和高盐不溶性基质成分，表明MC41是亚结构域特异性顶体基质蛋白。我们进一步研究了MC41与顶体蛋白酶和带蛋白的相互作用。在低盐条件下，75 kDa的丝氨酸蛋白酶与MC41相关，可能形成复合物。Far Western印迹技术表明，在高盐溶性精子蛋白存在的情况下，MC41同时与ZP2和ZP2(f)结合。在顶体反应精子中，MC41存在于由浆体和顶体外膜融合形成的杂交囊泡上。推测MC41在顶体反应中对次级精子带结合有重要作用。(C) 2001学术出版社。
Sperm with a large acrosome such as that of guinea pigs and hamsters have a subdomain structure in the anterior acrosome, but the mouse acrosome looks homogeneous and its matrix has not been precisely analyzed. The intra-acrosomal protein MC41 is localized in the cortical region of the mouse anterior acrosome, suggesting a subdomain structure in the mouse acrosome. Thus, the present study was undertaken to analyze the mouse acrosomal matrix using an anti-MC41 antibody. When mouse sperm were treated with 2% Triton X-100, Triton-insoluble matrix components remained in the acrosomal cortical region. Immunogold for MC41 labeled the Triton X-100 and high-salt-insoluble matrix components, demonstrating that MC41 is a subdomain-specific acrosomal matrix protein. We further examined interactions of MC41 with acrosomal proteases and zona proteins. A serine protease of 75 kDa was associated with MC41 under low-salt conditions, presumably forming, a complex. Far Western blotting technique indicated that MC41 bound to both ZP2 and ZP2(f) in the presence of high-salt-soluble sperm proteins. In acrosome-reacting sperm, MC41 was present on the hybrid vesicles formed by the fusion of the plasma and outer acrosomal membranes. Presumably, MC41 has a significant role in secondary sperm-zona binding during the acrosomal reaction. (C) 2001 Academic Press.