title: Is HAP2-GCS1 an ancestral gamete fusogen?
abstract: Eukaryotes employ a diversity of strategies to ensure that gametes come together, but the cellular climax is less varied: gamete plasma membranes must fuse to allow the combination of parental genomes. Recent studies of HAP2-GCS1, a sex-restricted transmembrane protein found in genomes representing all major eukaryotic taxa except fungi, suggest that a broad array of eukaryotic organisms could share a common mechanism for gamete fusion. Plant, protozoan, and algal gametes carrying loss-of-function mutations in HAP2-GCS1 fail to fuse with their complements. We propose that HAP2-GCS1 is a crucial component of an ancient mechanism that mediates the fusion of gamete plasma membranes and could have been a key early innovation in the evolution of sexual reproduction.
authors.affiliation: Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, 185 Meeting Street, Box G-L160, Providence, RI 02912, USA.
authors.forename: Julian L
authors.initials: JL
authors.lastname: Wong
authors.forename: Mark A
authors.initials: MA
authors.lastname: Johnson
mesh_terms: D000818:Animals; D029681:Arabidopsis Proteins / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics*; D002462:Cell Membrane / Q000502:physiology*; D002696:Chlamydomonas / Q000235:genetics; D056890:Eukaryota; D005306:Fertilization / Q000502:physiology; D005854:Germ Cells / Q000502:physiology*; D008561:Membrane Fusion / Q000235:genetics*; D010944:Plants / Q000235:genetics; D010961:Plasmodium / Q000235:genetics; D050600:SNARE Proteins / Q000502:physiology; D014764:Viral Proteins / Q000502:physiology
chemical_list: D029681:Arabidopsis Proteins; D002352:Carrier Proteins; C548817:HAP2 protein, Arabidopsis; D050600:SNARE Proteins; D014764:Viral Proteins