Pilt, a novel peripheral membrane protein at tight junctions in epithelial cells.
Tight junctions (TJs) serve as a barrier that prevents solutes and water from passing through the paracellular pathway, and as a fence between the apical and basolateral plasma membranes in epithelial cells. TJs consist of transmembrane proteins (claudin, occludin, and JAM) and many peripheral membrane proteins, including actin filament (F-actin)-binding scaffold proteins (ZO-1, -2, and -3), non-F-actin-binding scaffold proteins (MAGI-1), and cell polarity molecules (ASIP/PAR-3 and PAR-6). We identified here a novel peripheral membrane protein at TJs from a human cDNA library and named it Pilt (for protein incorporated later into TJs), because it was incorporated into TJs later after the claudin-based junctional strands were formed. Pilt consists of 547 amino acids with a calculated M(r) of 60,704. Pilt has a proline-rich domain. In cadherin-deficient L cells stably expressing claudin or JAM, Pilt was not recruited to claudin-based or JAM-based cell-cell contact sites, suggesting that Pilt does not directly interact with claudin or JAM. The present results indicate that Pilt is a novel component of TJs.
Kawabe
H
H
Department of Molecular Biology and Biochemistry, Osaka University Graduate School of Medicine/Faculty of Medicine, Suita 565-0871, Japan.
Nakanishi
H
H
Asada
M
M
Fukuhara
A
A
Morimoto
K
K
Takeuchi
M
M
Takai
Y
Y
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D018076:DNA, Complementary; D000074288:Discs Large Homolog 1 Protein; D004847:Epithelial Cells / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D011485:Protein Binding; D011506:Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013347:Subcellular Fractions; D062725:Tight Junction Proteins; D019108:Tight Junctions / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
D048868:Adaptor Proteins, Signal Transducing; C513314:DLG1 protein, human; D018076:DNA, Complementary; D000074288:Discs Large Homolog 1 Protein; D008565:Membrane Proteins; D011506:Proteins; C445327:TJAP1 protein, human; D062725:Tight Junction Proteins