Abstract
CEACAM1 is a signal-regulating, homophilic cell adhesion receptor system expressed in epithelia, vessel endothelia, and leukocytes. Here, we demonstrate that CEACAM1 is expressed also in PC12 cells, both as the common transmembrane isoforms, CEACAM1-L and CEACAM1-S, and as a novel, secreted, differentially spliced isoform. CEACAM1 can have both positive and negative effects on cell signaling. In an attempt to explain this dual behavior, we have initiated computational analysis of the signal-regulating effects of CEACAM1. This suggests that CEACAM1 can exert its signal-regulating activities by discriminating between binding of Src kinases and SHP phosphatases, respectively. Major factors that regulate this discrimination are the expression levels and expression ratios of transmembrane CEACAM1-L and CEACAM1-S, the concentration of secreted CEACAM1, and homophilic binding of CEACAM1 presented by neighboring cells.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Amino Acid Motifs
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Animals
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Antigens, CD / physiology*
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Antigens, Differentiation / physiology*
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Cell Adhesion
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Cell Adhesion Molecules
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Computational Biology / methods*
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Dose-Response Relationship, Drug
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Intracellular Signaling Peptides and Proteins
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Mitogen-Activated Protein Kinases / metabolism
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Models, Chemical
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PC12 Cells
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Phosphorylation
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Protein Binding
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Protein Isoforms
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Protein Structure, Tertiary
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Protein Tyrosine Phosphatase, Non-Receptor Type 6
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Protein Tyrosine Phosphatases / metabolism
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Proto-Oncogene Proteins pp60(c-src) / metabolism
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Rats
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Signal Transduction*
Substances
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Antigens, CD
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Antigens, Differentiation
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CD66 antigens
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Cell Adhesion Molecules
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Intracellular Signaling Peptides and Proteins
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Protein Isoforms
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Proto-Oncogene Proteins pp60(c-src)
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Mitogen-Activated Protein Kinases
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Protein Tyrosine Phosphatase, Non-Receptor Type 6
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Protein Tyrosine Phosphatases
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Ptpn6 protein, rat