Identification of a novel protein, LYRIC, localized to tight junctions of polarized epithelial cells.
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.
Britt
Deborah E
DE
Department of Medicine, Rhode Island Hospital/Brown University, Providence, RI 02903, USA. Deborah_Britt@brown.edu
Yang
Dong-Fang
DF
Yang
Dong-Qin
DQ
Flanagan
Donna
D
Callanan
Helen
H
Lim
Yow-Pin
YP
Lin
Sue-Hwa
SH
Hixson
Douglas C
DC
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
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