Cadherin 99C regulates apical expansion and cell rearrangement during epithelial tube elongation.
Apical and basolateral determinants specify and maintain membrane domains in epithelia. Here, we identify new roles for two apical surface proteins - Cadherin 99C (Cad99C) and Stranded at Second (SAS) - in conferring apical character in Drosophila tubular epithelia. Cad99C, the Drosophila ortholog of human Usher protocadherin PCDH15, is expressed in several embryonic tubular epithelial structures. Through loss-of-function and overexpression studies, we show that Cad99C is required to regulate cell rearrangement during salivary tube elongation. We further show that overexpression of either Cad99C or SAS causes a dramatic increase in apical membrane at the expense of other membrane domains, and that both proteins can do this independently of each other and independently of mislocalization of the apical determinant Crumbs (Crb). Overexpression of Cad99C or SAS results in similar, but distinct effects, suggesting both shared and unique roles for these proteins in conferring apical identity.
Department of Cell Biology, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205-2196, USA.
Seyeon
S
Chung
Deborah J
DJ
Andrew
D000818:Animals; D015820:Cadherins / Q000737:chemistry / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D016764:Cell Polarity; D029721:Drosophila Proteins / Q000378:metabolism; D004331:Drosophila melanogaster / Q000166:cytology* / Q000196:embryology* / Q000648:ultrastructure; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D004847:Epithelial Cells / Q000166:cytology* / Q000378:metabolism; D004848:Epithelium / Q000196:embryology* / Q000378:metabolism*; D005109:Extracellular Matrix / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D012469:Salivary Glands / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D013329:Structure-Activity Relationship; D020691:rab GTP-Binding Proteins / Q000378:metabolism
C512040:Cad99c protein, Drosophila; D015820:Cadherins; D029721:Drosophila Proteins; D008565:Membrane Proteins; C094135:Rab6 protein; C064360:crb protein, Drosophila; D020691:rab GTP-Binding Proteins
Apicobasal polarity; Drosophila; Epithelial organ development; Salivary gland; Tubulogenesis