title: Clustering-induced signaling of CEACAM1 in PC12 cells.
abstract: Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1), an Ig-like transmembrane protein, functions in cell adhesion, angiogenesis and epithelial cell morphogenesis, and has been identified as a tumor suppressor. For all of these functions, CEACAM1 requires signaling capabilities. However, the mechanisms of CEACAM1-mediated signaling are only poorly understood. Here we characterized for the first time CEACAM1 expression and signaling in the neuroendocrine rat pheochromocytoma PC12 cell line. Stimulation of CEACAM1 by ligation on the cell surface with antibodies induced formation of large CEACAM1 clusters and a rapid and transient CEACAM1 tyrosine dephosphorylation. Functionally, this dephosphorylation correlated with a reduced association between CEACAM1 and the tyrosine phosphatase SHP2. Clustering also stimulated binding of CEACAM1 to the actin cytoskeleton, measured by a partial translocation of CEACAM1 into the insoluble fraction after detergent extraction. Both tyrosine dephosphorylation and interaction with the cytoskeleton were sensitive to neuronal differentiation of PC12 cells. The first detected downstream activation of the mitogen-activated protein kinases ERK1 and ERK2, but not of JNK or p38, describes a novel target of CEACAM1-mediated signaling and contributes to the understanding of how CEACAM1 regulates cellular function.
authors.affiliation: Institut für Molekularbiologie und Biochemie, Fachbereich Humanmedizin, Freie Universität Berlin, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Budt
authors.forename: Iwona
authors.initials: I
authors.lastname: Cichocka
authors.forename: Werner
authors.initials: W
authors.lastname: Reutter
authors.forename: Lothar
authors.initials: L
authors.lastname: Lucka
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D000906:Antibodies / Q000378:metabolism; D015703:Antigens, CD / Q000096:biosynthesis / Q000378:metabolism / Q000502:physiology*; D000943:Antigens, Differentiation / Q000096:biosynthesis / Q000378:metabolism / Q000502:physiology*; D016466:CHO Cells / Q000166:cytology / Q000378:metabolism; D002272:Carcinoembryonic Antigen / Q000378:metabolism / Q000502:physiology; D015815:Cell Adhesion Molecules; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D006224:Cricetinae; D005434:Flow Cytometry; D007074:Immunoglobulin G / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D016716:PC12 Cells; D010766:Phosphorylation; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism; D051381:Rats; D015398:Signal Transduction / Q000502:physiology; D014443:Tyrosine / Q000378:metabolism
chemical_list: D000199:Actins; D000906:Antibodies; D015703:Antigens, CD; D000943:Antigens, Differentiation; C069847:CD66 antigens; D002272:Carcinoembryonic Antigen; D015815:Cell Adhesion Molecules; D007074:Immunoglobulin G; D047908:Intracellular Signaling Peptides and Proteins; D014443:Tyrosine; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D017027:Protein Tyrosine Phosphatases; C516727:Ptpn11 protein, rat