?-catenin is a molecular switch that regulates transition of cell-cell adhesion to fusion.

ABSTRACT: When a sperm and an oocyte unite upon fertilization, their cell membranes adhere and fuse, but little is known about the factors regulating sperm-oocyte adhesion. Here we explored the role of ?-catenin in sperm-oocyte adhesion. Biochemical analysis revealed that E-cadherin and ?-catenin formed a complex in oocytes and also in sperm. Sperm-oocyte adhesion was impaired when ?-catenin-deficient oocytes were inseminated with sperm. Furthermore, expression of ?-catenin decreased from the sperm head and the site of an oocyte to which a sperm adheres after completion of sperm-oocyte adhesion. UBE1-41, an inhibitor of ubiquitin-activating enzyme 1, inhibited the degradation of ?-catenin, and reduced the fusing ability of wild-type (but not ?-catenin-deficient) oocytes. These results indicate that ?-catenin is not only involved in membrane adhesion, but also in the transition to membrane fusion upon fertilization.

SUBMITTER: Takezawa Y 

PROVIDER: S-EPMC3216555 | biostudies-literature | 2011

REPOSITORIES: biostudies-literature