Mechanism of egg envelope digestion by hatching enzymes, HCE and LCE in medaka, Oryzias latipes.
Mechanism of egg envelope digestion by hatching enzymes, HCE and LCE in medaka, Oryzias latipes.
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DOI：
10.1093/jb/mvq086
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发表时间：
2010-10
影响因子：
2.7
通讯作者：
S. Yasumasu;M. Kawaguchi;S. Ouchi;K. Sano;K. Murata;H. Sugiyama;T. Akema;I. Iuchi
中科院分区：
文献类型：
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作者：
S. Yasumasu;M. Kawaguchi;S. Ouchi;K. Sano;K. Murata;H. Sugiyama;T. Akema;I. Iuchi
青鳉胚胎从受精卵被膜孵化涉及两种酶，HCE和LCE。我们确定了卵被膜上的HCE和LCE切割位点，这些位点主要由两组亚基蛋白ZI-1，2和ZI-3构成。HCE和LCE切割卵包膜蛋白上不同的靶序列，但共享一个共同的切割位点。HCE将ZI-1，2和ZI-3的N-末端区域（主要是ZI-1，2的Pro-Xaa-Yaa重复序列）切割成六肽，但不切割被认为是卵包膜核心结构的透明带（ZP）结构域内的位点。这些N-末端区域的裂解导致包膜的溶胀和软化。除了ZI-1，2的三叶结构域和ZI-3的ZP结构域的上游之外，LCE还切割ZI-1，2的ZP结构域的中间。该中间位点位于连接ZP结构域的两个亚结构域的间插序列中。切割该位点将通过破坏丝状结构导致溶胀的卵包膜溶解，所述丝状结构被认为是由ZP结构域的非共价聚合形成的。
Hatching of medaka embryos from the fertilized egg envelope involves two enzymes, HCE and LCE. HCE swells the envelope and then LCE completely dissolves it. We determined HCE and LCE cleavage sites on the egg envelope that are primarily constructed of two groups of subunit proteins, ZI-1,2 and ZI-3. HCE and LCE cleaved different target sequences on the egg envelope proteins but shared one common cleavage site. HCE cleaved the N-terminal region of ZI-1,2 and ZI-3, mainly the Pro-Xaa-Yaa repeat sequence of ZI-1,2 into hexapeptides, but not the site within a zona pellucida (ZP) domain that is considered to be the core structure of the egg envelope. The cleavage of these N-terminal regions results in swelling and softening of the envelope. LCE cleaved the middle of the ZP domain of ZI-1,2, in addition to the upstream of the trefoil domain of ZI-1,2 and the ZP domain of ZI-3. This middle site is in the intervening sequence connecting two subdomains of the ZP domain. Cleaving this site would result in the solubilization of the swollen egg envelope by the disruption of the filamentous structure that is thought to be formed by the non-covalent polymerization of ZP domains.