title: Structure, function, and expression of SEL-1, a negative regulator of LIN-12 and GLP-1 in C. elegans.
abstract: Previous work indicated that sel-1 functions as a negative regulator of lin-12 activity, and predicted that SEL-1 is a secreted or membrane associated protein. In this study, we describe cell ablation experiments that suggest sel-1 mutations elevate lin-12 activity cell autonomously. We also use transgenic approaches to demonstrate that the predicted signal sequence of SEL-1 can direct secretion and is important for function, while a C-terminal hydrophobic region is not required for SEL-1 function. In addition, by analyzing SEL-1 localization using specific antisera we find that SEL-1 is localized intracellularly, with a punctate staining pattern suggestive of membrane bound vesicles. We incorporate these observations, and new information about a related yeast gene, into a proposal for a possible mechanism for SEL-1 function in LIN-12 turnover.
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Howard Hughes Medical Institute, Columbia University, College of Physicians and Surgeons, New York, New York 10032, USA.
authors.forename: B
authors.initials: B
authors.lastname: Grant
authors.forename: I
authors.initials: I
authors.lastname: Greenwald
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D017173:Caenorhabditis elegans / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins; D019070:Cell Lineage; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D015801:Helminth Proteins / Q000235:genetics*; D008562:Membrane Glycoproteins / Q000235:genetics*; D008565:Membrane Proteins / Q000235:genetics*; D051880:Receptors, Notch
chemical_list: D029742:Caenorhabditis elegans Proteins; C060620:Glp-1 protein, C elegans; D015801:Helminth Proteins; C082460:Lin-12 protein, C elegans; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D051880:Receptors, Notch; C101221:SEL-1 protein, C elegans