title: Identification and expression analysis of the human mu-protocadherin gene in fetal and adult kidneys.
abstract: We recently cloned mu-protocadherin, a developmentally regulated cell adhesion molecule that contains an extracellular region with four cadherin-like ectodomains and a triply repeating mucin domain in its longer isoform. Expression of mu-protocadherin in L929 cells resulted in cellular aggregation, confirming its role in intercellular adhesion. We now identify the human mu-protocadherin ortholog and study its distribution in vivo and its targeting in polarized epithelia. Basic Local Alignment Search Tool searches and fluorescent in situ hybridization analysis on the basis of human-mouse synteny reveal that mu-protocadherin maps to 11p15.5, matching a previously identified gene called MUCDHL. At least three different splicing isoforms exist for MUCDHL that vary in expression in the fetal kidney. Mu-protocadherin is apically expressed along the brush border of the proximal convoluted tubule of the adult kidney. Transfection of truncated forms of mu-protocadherin into polarized Madin-Darby canine kidney cells reveals that the NH(2) terminus is essential for targeting to the apical surface. These results suggest that although human mu-protocadherin may mediate a homotypic adhesive interaction, it may have additional functions in terminally differentiated epithelia.
authors.affiliation: Department of Pediatrics, College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA. mg81@columbia.edu
authors.forename: Michael
authors.initials: M
authors.lastname: Goldberg
authors.forename: Michelle
authors.initials: M
authors.lastname: Wei
authors.forename: Benjamin
authors.initials: B
authors.lastname: Tycko
authors.forename: Inna
authors.initials: I
authors.lastname: Falikovich
authors.forename: Dorothy
authors.initials: D
authors.lastname: Warburton
mesh_terms: D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D000070585:Cadherin Related Proteins; D015820:Cadherins / Q000032:analysis / Q000737:chemistry / Q000235:genetics*; D002448:Cell Adhesion; D002460:Cell Line; D016384:Consensus Sequence; D004285:Dogs; D004848:Epithelium / Q000196:embryology / Q000254:growth & development / Q000378:metabolism; D015870:Gene Expression; D006031:Glycosylation; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D007668:Kidney / Q000196:embryology / Q000254:growth & development* / Q000378:metabolism*; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D009077:Mucins / Q000737:chemistry; D051381:Rats; D012091:Repetitive Sequences, Nucleic Acid; D016415:Sequence Alignment; D014162:Transfection
chemical_list: C413024:CDHR5 protein, human; D000070585:Cadherin Related Proteins; D015820:Cadherins; C504544:Cdhr5 protein, rat; D009077:Mucins