The Chlamydomonas Fus1 protein is present on the mating type plus fusion organelle and required for a critical membrane adhesion event during fusion with minus gametes.

ABSTRACT: The molecular mechanisms of the defining event in fertilization, gamete fusion, remain poorly understood. The FUS1 gene in the unicellular, biflagellated green alga Chlamydomonas is one of the few sex-specific eukaryotic genes shown by genetic analysis to be essential for gamete fusion during fertilization. In Chlamydomonas, adhesion and fusion of the plasma membranes of activated mt+ and mt- gametes is accomplished via specialized fusion organelles called mating structures. Herein, we identify the endogenous Fus1 protein, test the idea that Fus1 is at the site of fusion, and identify the step in fusion that requires Fus1. Our results show that Fus1 is a approximately 95-kDa protein present on the external surface of both unactivated and activated mt+ gametes. Bioassays indicate that adhes

SUBMITTER: Misamore MJ 

PROVIDER: S-EPMC194900 | biostudies-literature | 2003 Jun

REPOSITORIES: biostudies-literature