title: PATJ regulates tight junction formation and polarity in mammalian epithelial cells.
abstract: Recent studies have revealed an important role for tight junction protein complexes in epithelial cell polarity. One of these complexes contains the apical transmembrane protein, Crumbs, and two PSD95/discs large/zonula occludens domain proteins, protein associated with Lin seven 1 (PALS1)/Stardust and PALS1-associated tight junction protein (PATJ). Although Crumbs and PALS1/Stardust are known to be important for cell polarization, recent studies have suggested that Drosophila PATJ is not essential and its function is unclear. Here, we find that PATJ is targeted to the apical region and tight junctions once cell polarization is initiated. We show using RNAi techniques that reduction in PATJ expression leads to delayed tight junction formation as well as defects in cell polarization. These effects are reversed by reintroduction of PATJ into these RNAi cells. This study provides new functional information on PATJ as a polarity protein and increases our understanding of the Crumbs-PALS1-PATJ complex function in epithelial polarity.
authors.affiliation: Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
authors.forename: Kunyoo
authors.initials: K
authors.lastname: Shin
authors.forename: Sam
authors.initials: S
authors.lastname: Straight
authors.forename: Ben
authors.initials: B
authors.lastname: Margolis
mesh_terms: D000818:Animals; D016764:Cell Polarity / Q000502:physiology*; D004848:Epithelium / Q000378:metabolism; D005136:Eye Proteins / Q000378:metabolism*; D017930:Genes, Reporter; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism*; D034622:RNA Interference; D062725:Tight Junction Proteins; D019108:Tight Junctions / Q000378:metabolism*
chemical_list: D005136:Eye Proteins; D008565:Membrane Proteins; C107903:PATJ protein, human; D062725:Tight Junction Proteins
references.citation: J Biol Chem. 2000 Apr 14;275(15):11425-31
references.pmid: 10753959
references.citation: Nat Rev Mol Cell Biol. 2004 Mar;5(3):220-31
references.pmid: 14991002
references.citation: Nat Rev Mol Cell Biol. 2001 Apr;2(4):285-93
references.pmid: 11283726
references.citation: Nat Cell Biol. 2001 Sep;3(9):831-8
references.pmid: 11533663
references.citation: Curr Opin Cell Biol. 2001 Oct;13(5):641-8
references.pmid: 11544035
references.citation: Nature. 2001 Dec 6;414(6864):634-8
references.pmid: 11740559
references.citation: Nature. 2001 Dec 6;414(6864):638-43
references.pmid: 11740560
references.citation: Nature. 2002 Mar 14;416(6877):178-83
references.pmid: 11850624
references.citation: Nature. 2002 Mar 14;416(6877):143-9
references.pmid: 11850625
references.citation: J Cell Biol. 2002 Apr 1;157(1):161-72
references.pmid: 11927608
references.citation: Nat Rev Mol Cell Biol. 2002 Jul;3(7):531-7
references.pmid: 12094219
references.citation: J Biol Chem. 2002 Jul 12;277(28):25408-15
references.pmid: 11964389
references.citation: J Biol Chem. 2002 Jul 26;277(30):27501-9
references.pmid: 12021270
references.citation: Science. 2002 Dec 6;298(5600):1955-9
references.pmid: 12471248
references.citation: Gene. 2003 Jan 2;302(1-2):21-9
references.pmid: 12527193
references.citation: Nat Rev Mol Cell Biol. 2003 Mar;4(3):225-36
references.pmid: 12612641
references.citation: Nature. 2003 Apr 17;422(6933):766-74
references.pmid: 12700771
references.citation: J Cell Sci. 2003 Jul 15;116(Pt 14):2895-906
references.pmid: 12771187
references.citation: Am J Physiol Renal Physiol. 2003 Sep;285(3):F377-87
references.pmid: 12890661
references.citation: Development. 2003 Sep;130(18):4363-72
references.pmid: 12900452
references.citation: Dev Cell. 2003 Dec;5(6):841-51
references.pmid: 14667407
references.citation: Mol Biol Cell. 2004 Jan;15(1):176-88
references.pmid: 14528017
references.citation: Mol Biol Cell. 2004 Apr;15(4):1981-90
references.pmid: 14718565
references.citation: J Cell Biol. 1988 Nov;107(5):1717-28
references.pmid: 3053735
references.citation: Cell. 1990 Jun 1;61(5):787-99
references.pmid: 2344615
references.citation: J Cell Sci. 1995 Jan;108 ( Pt 1):127-42
references.pmid: 7738090
references.citation: Curr Biol. 1996 Apr 1;6(4):382-4
references.pmid: 8723338
references.citation: J Biol Chem. 1998 Nov 27;273(48):31633-6
references.pmid: 9822620
references.citation: Dev Biol. 1998 Dec 1;204(1):64-79
references.pmid: 9851843
references.citation: Cell. 1999 Mar 19;96(6):833-45
references.pmid: 10102271
references.citation: Mol Biol Cell. 2000 Sep;11(9):3045-60
references.pmid: 10982399