Homophilic Adhesion and CEACAM1-S Regulate Dimerization of CEACAM1-L and Recruitment of SHP-2 and C-Src
Overview
Affiliations
Carcinoembryonic antigen (CEA)-related cell adhesion molecule 1 (CAM1 [CEACAM1]) mediates homophilic cell adhesion and regulates signaling. Although there is evidence that CEACAM1 binds and activates SHP-1, SHP-2, and c-Src, knowledge about the mechanism of transmembrane signaling is lacking. To analyze the regulation of SHP-1/SHP-2/c-Src binding, we expressed various CFP/YFP-tagged CEACAM1 isoforms in epithelial cells. The supramolecular organization of CEACAM1 was examined by cross-linking, coclustering, coimmunoprecipitation, and fluorescence resonance energy transfer. SHP-1/SHP-2/c-Src binding was monitored by coimmunoprecipitation and phosphotyrosine-induced recruitment to CEACAM1-L in cellular monolayers. We find that trans-homophilic CEACAM1 binding induces cis-dimerization by an allosteric mechanism transmitted by the N-terminal immunoglobulin-like domain. The balance of SHP-2 and c-Src binding is dependent on the monomer/dimer equilibrium of CEACAM1-L and is regulated by trans-binding, whereas SHP-1 does not bind under physiological conditions. CEACAM1-L homodimer formation is reduced by coexpression of CEACAM1-S and modulated by antibody ligation. These data suggest that transmembrane signaling by CEACAM1 operates by alteration of the monomer/dimer equilibrium, which leads to changes in the SHP-2/c-Src-binding ratio.
The role of CEACAMs in neutrophil function.
Skubitz K Eur J Clin Invest. 2024; 54 Suppl 2:e14349.
PMID: 39674879 PMC: 11646290. DOI: 10.1111/eci.14349.
CEACAM1 in vascular homeostasis and inflammation.
Gotz L, Rueckschloss U, Ergun S, Kleefeldt F Eur J Clin Invest. 2024; 54 Suppl 2:e14345.
PMID: 39674877 PMC: 11646292. DOI: 10.1111/eci.14345.
Carcinoembryonic antigen-related cell adhesion molecule 1 in cancer: Blessing or curse?.
Gotz L, Rueckschloss U, Najjar S, Ergun S, Kleefeldt F Eur J Clin Invest. 2024; 54 Suppl 2:e14337.
PMID: 39451132 PMC: 11646294. DOI: 10.1111/eci.14337.
The role of carcinoembryonic antigen-related cell adhesion molecule 1 in cancer.
Gotz L, Rueckschloss U, Balk G, Pfeiffer V, Ergun S, Kleefeldt F Front Immunol. 2023; 14:1295232.
PMID: 38077351 PMC: 10704240. DOI: 10.3389/fimmu.2023.1295232.
Effects of adhesin HopQ binding to CEACAM receptors in the human stomach.
Nguyen Q, Schmitt L, Mejias-Luque R, Gerhard M Front Immunol. 2023; 14:1113478.
PMID: 36891299 PMC: 9986547. DOI: 10.3389/fimmu.2023.1113478.