lin-8, which antagonizes Caenorhabditis elegans Ras-mediated vulval induction, encodes a novel nuclear protein that interacts with the LIN-35 Rb protein.
Ras-mediated vulval development in C. elegans is inhibited by the functionally redundant sets of class A, B, and C synthetic Multivulva (synMuv) genes. Three of the class B synMuv genes encode an Rb/DP/E2F complex that, by analogy with its mammalian and Drosophila counterparts, has been proposed to silence genes required for vulval specification through chromatin modification and remodeling. Two class A synMuv genes, lin-15A and lin-56, encode novel nuclear proteins that appear to function as a complex. We show that a third class A synMuv gene, lin-8, is the defining member of a novel C. elegans gene family. The LIN-8 protein is nuclear and can interact physically with the product of the class B synMuv gene lin-35, the C. elegans homolog of mammalian Rb. LIN-8 likely acts with the synMuv A proteins LIN-15A and LIN-56 in the nucleus, possibly in a protein complex with the synMuv B protein LIN-35 Rb. Other LIN-8 family members may function in similar complexes in different cells or at different stages. The nuclear localization of LIN-15A, LIN-56, and LIN-8, as well as our observation of a direct physical interaction between class A and class B synMuv proteins, supports the hypothesis that the class A synMuv genes control vulval induction through the transcriptional regulation of gene expression.
Davison
Ewa M
EM
Department of Biology, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Harrison
Melissa M
MM
Walhout
Albertha J M
AJ
Vidal
Marc
M
Horvitz
H Robert
HR
D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics* / Q000378:metabolism*; D005260:Female; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism*; D014844:Vulva / Q000196:embryology*; D018631:ras Proteins / Q000037:antagonists & inhibitors / Q000502:physiology*
D029742:Caenorhabditis elegans Proteins; C508096:LIN-8 protein, C elegans; D009687:Nuclear Proteins; D012097:Repressor Proteins; C116485:lin-35 protein, C elegans; D018631:ras Proteins