title: Identification of a novel protein, LYRIC, localized to tight junctions of polarized epithelial cells.
abstract: Tight junctions (TJ) are multiprotein complexes that function to regulate paracellular transport of molecules through epithelial and endothelial cell layers. Many new tight junction-associated proteins have been identified in the past few years, and their functional roles and interactions have just begun to be elucidated. In this paper, we describe a novel protein LYsine-RIch CEACAM1 co-isolated (LYRIC) that is widely expressed and highly conserved between species. LYRIC has no conserved domains that would indicate function and does not appear to be a member of a larger protein family. Data from analysis of rat and human tissue sections and cell lines show that LYRIC colocalizes with tight junction proteins ZO-1 and occludin in polarized epithelial cells, suggesting that LYRIC is part of the tight junction complex. LYRIC dissociates from ZO-1 when junctional complexes are disrupted, and as tight junctions reform, ZO-1 relocalizes before LYRIC. These results suggest that LYRIC is most likely not a structural component required for TJ formation, but rather is recruited during the maturation of the tight junction complex.
authors.affiliation: Department of Medicine, Rhode Island Hospital/Brown University, Providence, RI 02903, USA. Deborah_Britt@brown.edu
authors.forename: Deborah E
authors.initials: DE
authors.lastname: Britt
authors.forename: Dong-Fang
authors.initials: DF
authors.lastname: Yang
authors.forename: Dong-Qin
authors.initials: DQ
authors.lastname: Yang
authors.forename: Donna
authors.initials: D
authors.lastname: Flanagan
authors.forename: Helen
authors.initials: H
authors.lastname: Callanan
authors.forename: Yow-Pin
authors.initials: YP
authors.lastname: Lim
authors.forename: Sue-Hwa
authors.initials: SH
authors.lastname: Lin
authors.forename: Douglas C
authors.initials: DC
authors.lastname: Hixson
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D000943:Antigens, Differentiation / Q000378:metabolism; D015820:Cadherins / Q000378:metabolism; D002352:Carrier Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D002448:Cell Adhesion / Q000235:genetics; D015815:Cell Adhesion Molecules; D002460:Cell Line; D045744:Cell Line, Tumor; D016764:Cell Polarity / Q000235:genetics*; D018076:DNA, Complementary / Q000032:analysis / Q000235:genetics; D004847:Epithelial Cells / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000378:metabolism; D016601:RNA-Binding Proteins; D051381:Rats; D011916:Rats, Inbred F344; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D019108:Tight Junctions / Q000378:metabolism* / Q000648:ultrastructure; D062826:Zonula Occludens-1 Protein
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; C069847:CD66 antigens; D015820:Cadherins; D002352:Carrier Proteins; D015815:Cell Adhesion Molecules; D018076:DNA, Complementary; C483039:MTDH protein, human; D008565:Membrane Proteins; C493282:Mtdh protein, rat; D010750:Phosphoproteins; D016601:RNA-Binding Proteins; C569042:TJP1 protein, human; C569044:Tjp1 protein, rat; D062826:Zonula Occludens-1 Protein