title: AFF-1, a FOS-1-regulated fusogen, mediates fusion of the anchor cell in C. elegans.
abstract: Cell fusion is fundamental for reproduction and organ formation. Fusion between most C. elegans epithelial cells is mediated by the EFF-1 fusogen. However, fusion between the anchor cell and the utse syncytium that establishes a continuous uterine-vulval tube proceeds normally in eff-1 mutants. By isolating mutants where the anchor-cell fails to fuse, we identified aff-1. AFF-1 ectopic expression results in fusion of cells that normally do not fuse in C. elegans. The fusogen activity of AFF-1 was further confirmed by its ability to fuse heterologous cells. AFF-1 and EFF-1 differ in their fusogenic activity and expression patterns but share eight conserved predicted disulfide bonds in their ectodomains, including a putative TGF-beta-type-I-Receptor domain. We found that FOS-1, the Fos transcription factor ortholog that controls anchor-cell invasion during nematode development, is a specific activator of aff-1-mediated anchor-cell fusion. Thus, FOS-1 links cell invasion and fusion in a developmental cascade.
authors.affiliation: Department of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel.
authors.forename: Amir
authors.initials: A
authors.lastname: Sapir
authors.forename: Jaebok
authors.initials: J
authors.lastname: Choi
authors.forename: Evgenia
authors.initials: E
authors.lastname: Leikina
authors.forename: Ori
authors.initials: O
authors.lastname: Avinoam
authors.forename: Clari
authors.initials: C
authors.lastname: Valansi
authors.forename: Leonid V
authors.initials: LV
authors.lastname: Chernomordik
authors.forename: Anna P
authors.initials: AP
authors.lastname: Newman
authors.forename: Benjamin
authors.initials: B
authors.lastname: Podbilewicz
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000166:cytology* / Q000196:embryology / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry / Q000378:metabolism*; D002459:Cell Fusion; D003593:Cytoplasm / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000166:cytology; D004847:Epithelial Cells / Q000166:cytology; D005260:Female; D007313:Insecta / Q000166:cytology; D008954:Models, Biological; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D016760:Proto-Oncogene Proteins c-fos / Q000737:chemistry / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D014844:Vulva / Q000166:cytology / Q000254:growth & development
chemical_list: C520081:AFF-1 protein, C elegans; D029742:Caenorhabditis elegans Proteins; C520083:FOS-1 protein, C elegans; D016760:Proto-Oncogene Proteins c-fos; D014157:Transcription Factors