title: lag-1, a gene required for lin-12 and glp-1 signaling in Caenorhabditis elegans, is homologous to human CBF1 and Drosophila Su(H).
abstract: The homologous receptors LIN-12 and GLP-1 mediate diverse cell-signaling events during development of the nematode Caenorhabditis elegans. These two receptors appear to be functionally interchangeable and have sequence similarity to Drosophila Notch. Here we focus on a molecular analysis of the lag-1 gene (lin-12 -and glp-1), which plays a central role in LIN-12 and GLP-1-mediated signal transduction. We find that the predicted LAG-1 protein is homologous to two DNA-binding proteins: human C Promoter Binding Factor (CBF1) and Drosophila Suppressor of Hairless (Su(H)). Furthermore, we show that LAG-1 binds specifically to the DNA sequence RTGGGAA, previously identified as a CBF-1/Su(H)-binding site. Finally, we report that the 5' flanking regions and first introns of the lin-12, glp-1 and lag-1 genes are enriched for potential LAG-1-binding sites. We propose that LAG-1 is a transcriptional regulator that serves as a primary link between the LIN-12 and GLP-1 receptors and downstream target genes in C. elegans. In addition, we propose that LAG-1 may be a key component of a positive feedback loop that amplifies activity of the LIN-12/GLP-1 pathway.
authors.affiliation: Department of Genetics, University of Wisconsin-Madison 53706, USA.
authors.forename: S
authors.initials: S
authors.lastname: Christensen
authors.forename: V
authors.initials: V
authors.lastname: Kodoyianni
authors.forename: M
authors.initials: M
authors.lastname: Bosenberg
authors.forename: L
authors.initials: L
authors.lastname: Friedman
authors.forename: J
authors.initials: J
authors.lastname: Kimble
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D029721:Drosophila Proteins; D017238:Genes, Helminth; D015801:Helminth Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D051819:Immunoglobulin J Recombination Signal Sequence-Binding Protein; D008562:Membrane Glycoproteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins; D016133:Polymerase Chain Reaction; D011485:Protein Binding; D051880:Receptors, Notch; D012097:Repressor Proteins / Q000235:genetics; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction
chemical_list: D029742:Caenorhabditis elegans Proteins; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; C060620:Glp-1 protein, C elegans; D015801:Helminth Proteins; D051819:Immunoglobulin J Recombination Signal Sequence-Binding Protein; C099355:LAG-1 protein, C elegans; C082460:Lin-12 protein, C elegans; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009687:Nuclear Proteins; C497570:RBPJ protein, human; D051880:Receptors, Notch; D012097:Repressor Proteins; C088731:Su(H) protein, Drosophila