title: lag-2 may encode a signaling ligand for the GLP-1 and LIN-12 receptors of C. elegans.
abstract: The C. elegans lag-2 gene is required for several cell-cell interactions that rely on the receptors GLP-1 and LIN-12. In this paper, we report that lag-2 encodes a putative membrane protein with sequence similarity to Drosophila Delta, a proposed ligand for the Notch receptor. Furthermore, we show that the lag-2 promoter drives expression of a reporter protein in the signaling distal tip cell (DTC) of the DTC/germline interaction. By in situ hybridization, we have found that endogenous lag-2 mRNA is present in the DTC but not the germ line. One fusion protein, called LAG-2::beta-gal(intra), rescues a lag-2 null mutant and can be detected in both DTC and germ line. Taking these results together, we propose that lag-2 may encode a signaling ligand for GLP-1/LIN-12 and that the entire LAG-2 protein may be taken up into the receiving cell during induction by GLP-1 and lateral signaling by LIN-12.
authors.affiliation: Laboratory of Molecular Biology, University of Wisconsin, Madison 53706, USA.
authors.forename: S T
authors.initials: ST
authors.lastname: Henderson
authors.forename: D
authors.initials: D
authors.lastname: Gao
authors.forename: E J
authors.initials: EJ
authors.lastname: Lambie
authors.forename: J
authors.initials: J
authors.lastname: Kimble
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000235:genetics; D029742:Caenorhabditis elegans Proteins; D017931:DNA Primers; D004627:Embryonic Induction / Q000502:physiology*; D015801:Helminth Proteins / Q000235:genetics*; D017403:In Situ Hybridization; D008562:Membrane Glycoproteins / Q000235:genetics*; D008565:Membrane Proteins / Q000235:genetics* / Q000502:physiology; D008969:Molecular Sequence Data; D051880:Receptors, Notch; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D029742:Caenorhabditis elegans Proteins; D017931:DNA Primers; C060620:Glp-1 protein, C elegans; D015801:Helminth Proteins; C082460:Lin-12 protein, C elegans; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D051880:Receptors, Notch; C086488:lag-2 protein, C elegans