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C-CAM-mediated adhesion leads to an outside-in dephosphorylation signal

L Lucka1, M Budt, I Cichocka

  • 1Institut für Molekularbiologie und Biochemie, Universitätsklinikum Benjamin Franklin, Freie Universität Berline, Germany. lucka@zedat.fu-berlin.de

European Journal of Biochemistry
|May 21, 1999
PubMed

Insights

Cell-cell adhesion molecule C-CAML

Area of Science:

  • Cell biology
  • Molecular biology
  • Biochemistry

Background:

  • The rat cell-cell adhesion molecule C-CAM, part of the carcinoembryonic antigen family, exists in isoforms with varying cytoplasmic domains.
  • The long isoform, C-CAML, inhibits malignant cell growth and is implicated in signal transduction.

Purpose of the Study:

  • To investigate the relationship between C-CAM-mediated adhesion and phosphorylation of its cytoplasmic domain.
  • To determine if cell-cell adhesion triggers changes in C-CAML phosphorylation.

Main Methods:

  • Analyzing C-CAML phosphorylation levels in adherent and suspension cell cultures.
  • Quantifying C-CAML phosphorylation during cell aggregation.
  • Inducing C-CAML clustering using antibodies to observe phosphorylation changes.

Main Results:

  • C-CAML is constitutively phosphorylated in both adherent and suspension cells.
  • C-CAML-mediated cell aggregation led to a significant reduction (40%) in C-CAML phosphorylation.
  • Antibody-induced C-CAML clustering also resulted in dephosphorylation.

Conclusions:

  • C-cell adhesion triggers outside-in signaling, indicated by C-CAML dephosphorylation.
  • Changes in C-CAML phosphorylation are directly linked to its adhesive function.
  • This suggests a dynamic role for C-CAML phosphorylation in cell-cell interactions.

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