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Updated: Aug 10, 2026

Analysis of SNARE-mediated Membrane Fusion Using an Enzymatic Cell Fusion Assay
Published on: October 19, 2012
A potential fusion peptide and an integrin ligand domain in a protein active in sperm-egg fusion
C P Blobel1, T G Wolfsberg, C W Turck
1Department of Pharmacology, University of California San Francisco.
Abstract:
The union of sperm and egg is a special membrane fusion event that gives a signal to begin development. We have hypothesized that proteins mediating cell-cell fusion events resemble viral fusion proteins and have shown that PH-30, a sperm surface protein involved in sperm-egg fusion, shares biochemical characteristics with viral fusion proteins. We report here the complementary DNA and deduced amino-acid sequences of the mature alpha and beta subunits of PH-30. Both are type-I integral membrane glycoproteins. The alpha subunit contains a putative fusion peptide typical of viral fusion proteins and the beta subunit contains a domain related to a family of soluble integrin ligands found in snake venoms. Thus, the PH-30 alpha/beta complex resembles many viral fusion proteins in both its membrane topology and its predicted binding and fusion functions.
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