title: Cell adhesion molecule CEACAM1 associates with paxillin in granulocytes and epithelial and endothelial cells.
abstract: CEACAM1 functions as an epithelial tumor suppressor and as an angiogenic growth factor. In the present study, utilizing differentially (serine/threonine or tyrosine) phosphorylated cytoplasmic domains of CEACAM1 and CEACAM3 as bait to isolate associated proteins from granulocyte extracts, we have identified human paxillin as a binding partner of the tyrosine-phosphorylated cytoplasmic CEACAM1 domain. CEACAM1-paxillin complexes were coimmunoprecipitated from extracts of granulocytes, the colonic cell line HT29, and HUVECs. We identified phosphorylated Tyr-488-a residue in the cytoplasmic CEACAM1 domain known to be essential for the tumor suppressive effect-to be necessary for this association. The CEACAM1-paxillin interaction was confirmed using laser scanning confocal microscopy analyses in granulocytes and HT29 cells, where CEACAM1 colocalizes with paxillin at the plasma membrane. In HUVECs a highly polarized expression pattern and colocalization of paxillin and CEACAM1 was observed. These findings support the findings that CEACAM1 is linked to the actin-based cytoskeleton.
authors.affiliation: Abteilung für Klinische Chemie, Klinik und Poliklinik für Innere Medizin, Universitätsklinikum Hamburg-Eppendorf, Martinistrasse 52, Hamburg, 20246, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Ebrahimnejad
authors.forename: R
authors.initials: R
authors.lastname: Flayeh
authors.forename: G
authors.initials: G
authors.lastname: Unteregger
authors.forename: C
authors.initials: C
authors.lastname: Wagener
authors.forename: J
authors.initials: J
authors.lastname: Brümmer
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism*; D000943:Antigens, Differentiation / Q000378:metabolism*; D001665:Binding Sites; D002272:Carcinoembryonic Antigen; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002457:Cell Extracts; D003593:Cytoplasm / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D006023:Glycoproteins; D006098:Granulocytes / Q000166:cytology / Q000378:metabolism*; D019073:HT29 Cells; D006801:Humans; D051379:Mice; D051419:Paxillin; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D011233:Precipitin Tests; D014443:Tyrosine / Q000378:metabolism
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; C069847:CD66 antigens; D002272:Carcinoembryonic Antigen; C486183:Ceacam1 protein, mouse; C087701:Ceacam2 protein, mouse; D015815:Cell Adhesion Molecules; D002457:Cell Extracts; D003598:Cytoskeletal Proteins; D006023:Glycoproteins; C496061:PXN protein, human; D051419:Paxillin; D010750:Phosphoproteins; C496062:Pxn protein, mouse; D014443:Tyrosine; D000251:Adenosine Triphosphatases