title: Drosophila melanogaster Cad99C, the orthologue of human Usher cadherin PCDH15, regulates the length of microvilli.
abstract: Actin-based protrusions can form prominent structures on the apical surface of epithelial cells, such as microvilli. Several cytoplasmic factors have been identified that control the dynamics of actin filaments in microvilli. However, it remains unclear whether the plasma membrane participates actively in microvillus formation. In this paper, we analyze the function of Drosophila melanogaster cadherin Cad99C in the microvilli of ovarian follicle cells. Cad99C contributes to eggshell formation and female fertility and is expressed in follicle cells, which produce the eggshells. Cad99C specifically localizes to apical microvilli. Loss of Cad99C function results in shortened and disorganized microvilli, whereas overexpression of Cad99C leads to a dramatic increase of microvillus length. Cad99C that lacks most of the cytoplasmic domain, including potential PDZ domain-binding sites, still promotes excessive microvillus outgrowth, suggesting that the amount of the extracellular domain determines microvillus length. This study reveals Cad99C as a critical regulator of microvillus length, the first example of a transmembrane protein that is involved in this process.
authors.affiliation: Department of Zoology, University of Toronto, Toronto, Ontario, Canada, M5S 3G5.
authors.forename: Cecilia
authors.initials: C
authors.lastname: D'Alterio
authors.forename: Dao D D
authors.initials: DD
authors.lastname: Tran
authors.forename: Maggie W Y Au
authors.initials: MW
authors.lastname: Yeung
authors.forename: Michael S H
authors.initials: MS
authors.lastname: Hwang
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Li
authors.forename: Claudia J
authors.initials: CJ
authors.lastname: Arana
authors.forename: Vikram K
authors.initials: VK
authors.lastname: Mulligan
authors.forename: Mary
authors.initials: M
authors.lastname: Kubesh
authors.forename: Praveer
authors.initials: P
authors.lastname: Sharma
authors.forename: Maretta
authors.initials: M
authors.lastname: Chase
authors.forename: Ulrich
authors.initials: U
authors.lastname: Tepass
authors.forename: Dorothea
authors.initials: D
authors.lastname: Godt
mesh_terms: D000818:Animals; D000070585:Cadherin Related Proteins; D015820:Cadherins / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D008871:Microvilli / Q000502:physiology / Q000648:ultrastructure; D009866:Oogenesis; D006080:Ovarian Follicle / Q000502:physiology / Q000648:ultrastructure; D011498:Protein Precursors / Q000235:genetics*; D017434:Protein Structure, Tertiary
chemical_list: C498835:CDHR15, human; D000070585:Cadherin Related Proteins; D015820:Cadherins; D029721:Drosophila Proteins; D011498:Protein Precursors