title: A novel planar polarity gene pepsinogen-like regulates wingless expression in a posttranscriptional manner.
abstract: BACKGROUND
  Planar cell polarity (PCP) originally referred to the coordination of global organ axes and individual cell polarity within the plane of the epithelium. More recently, it has been accepted that pertinent PCP regulators play essential roles not only in epithelial sheets, but also in various rearranging cells.
  
  
  RESULTS
  We identified pepsinogen-like (pcl) as a new planar polarity gene, using Drosophila wing epidermis as a model. Pcl protein is predicted to belong to a family of aspartic proteases. When pcl mutant clones were observed in pupal wings, PCP was disturbed in both mutant and wild-type cells that were juxtaposed to the clone border. We examined levels of known PCP proteins in wing imaginal discs. The amount of the seven-pass transmembrane cadherin Flamingo (Fmi), one of the PCP "core group" members, was significantly decreased in mutant clones, whereas neither the amount of nor the polarized localization of Dachsous (Ds) at cell boundaries was affected. In addition to the PCP phenotype, the pcl mutation caused loss of wing margins. Intriguingly, this was most likely due to a dramatic decrease in the level of Wingless (Wg) protein, but not due to a decrease in the level of wg transcripts.
  
  
  CONCLUSIONS
  Our results raise the possibility that Pcl regulates Wg expression post-transcriptionally, and PCP, by proteolytic cleavages.
authors.affiliation: Graduate School of Biostudies, Kyoto University, Kyoto, Japan.
authors.forename: Kousuke
authors.initials: K
authors.lastname: Mouri
authors.forename: Yutaro
authors.initials: Y
authors.lastname: Nishino
authors.forename: Masaki
authors.initials: M
authors.lastname: Arata
authors.forename: Dongbo
authors.initials: D
authors.lastname: Shi
authors.forename: Shin-Ya
authors.initials: SY
authors.lastname: Horiuchi
authors.forename: Tadashi
authors.initials: T
authors.lastname: Uemura
mesh_terms: D000818:Animals; D015820:Cadherins / Q000378:metabolism*; D029721:Drosophila Proteins / Q000096:biosynthesis* / Q000378:metabolism*; D004331:Drosophila melanogaster; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000196:embryology*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D060227:Imaginal Discs / Q000166:cytology / Q000196:embryology*; D059748:Proteolysis; D051155:Wnt1 Protein / Q000096:biosynthesis*
chemical_list: D015820:Cadherins; D029721:Drosophila Proteins; D051155:Wnt1 Protein; C094449:ds protein, Drosophila; C074622:wg protein, Drosophila
keywords: Drosophila melanogaster; Wnt signaling pathway; aspartic protease; planar cell polarity