RGD Reference Report - The cell-cell adhesion molecule EpCAM interacts directly with the tight junction protein claudin-7. - Rat Genome Database
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The cell-cell adhesion molecule EpCAM interacts directly with the tight junction protein claudin-7.

Authors: Ladwein, M  Pape, UF  Schmidt, DS  Schnolzer, M  Fiedler, S  Langbein, L  Franke, WW  Moldenhauer, G  Zoller, M 
Citation: Ladwein M, etal., Exp Cell Res. 2005 Oct 1;309(2):345-57.
RGD ID: 8554775
Pubmed: (View Article at PubMed) PMID:16054130
DOI: Full-text: DOI:10.1016/j.yexcr.2005.06.013

We recently described that in the metastasizing rat pancreatic carcinoma line BSp73ASML the cell-cell adhesion molecule EpCAM, CD44 variant isoforms and the tetraspanins D6.1A and CD9 form a complex that is located in glycolipid-enriched membrane microdomains. This complex contains, in addition, an undefined 20 kDa protein. As such complex formation influenced cell-cell adhesion and apoptosis resistance, it became of interest to identify the 20 kDa polypeptide. This 20 kDa protein, which co-precipitated with EpCAM in BSp73ASML lysates, was identified as the tight junction protein claudin-7. Correspondingly, an association between EpCAM and claudin-7 was noted in rat and human tumors and in non-transformed tissues of the gastrointestinal tract. Co-localization of the two molecules was most pronounced at basolateral membranes, but was also observed in tight junctions. Evidence for direct protein-protein interactions between EpCAM and claudin-7 was obtained by co-immunoprecipitation after treatment of tumor cells with a membrane-permeable chemical cross-linker. The complex, which is located in glycolipid-enriched membrane microdomains, is not disrupted by partial cholesterol depletion, but claudin-7 phosphorylation is restricted to the localization in glycolipid-enriched membrane microdomains. This is the first report on an association between EpCAM and claudins in both non-transformed tissues and metastasizing tumor cell lines.

Annotation

Gene Ontology Annotations    

Cellular Component

Objects Annotated

Genes (Rattus norvegicus)
Epcam  (epithelial cell adhesion molecule)


Additional Information