title: The cell adhesion molecule L1 is developmentally regulated in the renal epithelium and is involved in kidney branching morphogenesis.
abstract: We immunopurified a surface antigen specific for the collecting duct (CD) epithelium. Microsequencing of three polypeptides identified the antigen as the neuronal cell adhesion molecule L1, a member of the immunoglobulin superfamily. The kidney isoform showed a deletion of exon 3. L1 was expressed in the mesonephric duct and the metanephros throughout CD development. In the adult CD examined by electron microscopy, L1 was not expressed on intercalated cells but was restricted to CD principal cells and to the papilla tall cells. By contrast, L1 appeared late in the distal portion of the elongating nephron in the mesenchymally derived epithelium and decreased during postnatal development. Immunoblot analysis showed that expression, proteolytic cleavage, and the glycosylation pattern of L1 protein were regulated during renal development. L1 was not detected in epithelia of other organs developing by branching morphogenesis. Addition of anti-L1 antibody to kidney or lung organotypic cultures induced dysmorphogenesis of the ureteric bud epithelium but not of the lung. These results suggest a functional role for L1 in CD development in vitro. We further postulate that L1 may be involved in the guidance of developing distal tubule and in generation and maintenance of specialized cell phenotypes in CD.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale (INSERM) Unité 489, Hôpital Tenon, 75020 Paris, France. biblio.inserm@tnn.ap-hp-paris.fr
authors.forename: H
authors.initials: H
authors.lastname: Debiec
authors.forename: E I
authors.initials: EI
authors.lastname: Christensen
authors.forename: P M
authors.initials: PM
authors.lastname: Ronco
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017487:Ankyrins / Q000378:metabolism; D002448:Cell Adhesion; D004847:Epithelial Cells / Q000378:metabolism; D005091:Exons; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D007668:Kidney / Q000166:cytology / Q000196:embryology*; D039841:Leukocyte L1 Antigen Complex; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D008650:Mesonephros / Q000378:metabolism*; D008969:Molecular Sequence Data; D009024:Morphogenesis; D019006:Neural Cell Adhesion Molecules / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D009924:Organ Culture Techniques; D020033:Protein Isoforms / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D011817:Rabbits; D016415:Sequence Alignment; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D014513:Ureter / Q000166:cytology / Q000196:embryology
chemical_list: D017487:Ankyrins; D039841:Leukocyte L1 Antigen Complex; D008562:Membrane Glycoproteins; D019006:Neural Cell Adhesion Molecules; D020033:Protein Isoforms