Cell adhesion molecule CEACAM1 associates with paxillin in granulocytes and epithelial and endothelial cells.
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.
Ebrahimnejad
A
A
Abteilung für Klinische Chemie, Klinik und Poliklinik für Innere Medizin, Universitätsklinikum Hamburg-Eppendorf, Martinistrasse 52, Hamburg, 20246, Germany.
Flayeh
R
R
Unteregger
G
G
Wagener
C
C
Brümmer
J
J
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
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