Work

Direct Interaction of Tumor Suppressor CEACAM1 with Beta Catenin: Identification of Key Residues in the Long Cytoplasmic Domain

Year: 2008

Type: article

Abstract: CEACAM1-4L (carcinoembryonic antigen cell adhesion molecule 1, with 4 extracellular Ig-like domains and a long, 71 amino acid cytoplasmic domain) is expressed in epithelial cells and activated T-cells, but is down-regulated in most epithelial cell cancers and T-cell leukemias. A highly conserved sequence within the cytoplasmic domain has ca 50% sequence homology with Tcf-3 and -4, transcription factors that bind beta-catenin, and to a lesser extent (32% homology), with E-cadherin that also binds beta-catenin. We show by quantitative yeast two-hybrid, BIAcore, GST-pull down, and confocal analyses that this domain directly interacts with beta-catenin, and that H-469 and K-470 are key residues that interact with the armadillo repeats of beta-catenin. Jurkat cells transfected with CEACAM1-4L have 2-fold less activity in the TOPFLASH reporter assay, and in MCF7 breast cancer cells that fail to express CEACAM1, transfection with CEACAM1 and growth in Ca2+ media causes redistribution of beta-catenin from the cytoplasm to the cell membrane, demonstrating a functional role for the long cytoplasmic domain of CEACAM1 in regulation of beta-catenin activity.

Source: Experimental Biology and Medicine

DOI: 10.3181/0712-rm-352

Authors: Lan Jin, Yun Li, Charng-Jui Chen, Mark A. Sherman, Keith Le, John E. Shively

Institution: Beckman Research Institute

Language: English

Topic: Wnt/β-catenin signaling in development and cancer

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: green

Funder: National Cancer Institute