AFF-1, a FOS-1-regulated fusogen, mediates fusion of the anchor cell in C. elegans.
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.
Sapir
Amir
A
Department of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel.
Choi
Jaebok
J
Leikina
Evgenia
E
Avinoam
Ori
O
Valansi
Clari
C
Chernomordik
Leonid V
LV
Newman
Anna P
AP
Podbilewicz
Benjamin
B
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
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