The cell adhesion molecule CEACAM1-L is a substrate of caspase-3-mediated cleavage in apoptotic mouse intestinal cells

J Biol Chem. 2003 May 9;278(19):16929-35. doi: 10.1074/jbc.M301842200. Epub 2003 Mar 11.

Abstract

The CEACAM1 cell adhesion molecule is a member of the carcinoembryonic antigen family. In the mouse, four distinct isoforms are generated by alternative splicing. These encode either two or four immunoglobulin domains linked through a transmembrane domain to a cytoplasmic domain that encompasses either a short 10-amino acid tail or a longer one of 73 amino acids. Inclusion of exon 7, well conserved in evolution, generates the long cytoplasmic domain. A potential caspase recognition site in mouse, rat, and human CEACAM1-L also becomes available within the peptide encoded by exon 7. We used CEACAM1-L-transfected mouse colon carcinoma CT51 cells treated with three different apoptotic agents to study its fate during cell death. We found that CEACAM1-L is cleaved resulting in rapid degradation of most of its 8-kDa cytoplasmic domain. Caspase-mediated cleavage was demonstrated using purified recombinant caspases. The long cytoplasmic domain was cleaved specifically by caspase-3 in vitro but not by caspase-7 or -8. Moreover cleavage of CEACAM1-L in apoptotic cells was blocked by addition of a selective caspase-3 inhibitor to the cultures. Using point and deletion mutants, the conserved DQRD motif in the membrane-proximal cytoplasmic domain was identified as a caspase cleavage site. We also show that once CEACAM1-L is caspase-cleaved it becomes a stronger adhesion molecule than both the shorter and the longer expressing isoforms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antigens, CD / chemistry
  • Antigens, CD / metabolism*
  • Antigens, Differentiation / chemistry
  • Antigens, Differentiation / metabolism*
  • Apoptosis / physiology*
  • Carcinoembryonic Antigen
  • Caspase 3
  • Caspases / metabolism*
  • Cell Adhesion Molecules
  • Cell Line
  • Colonic Neoplasms / metabolism
  • Colonic Neoplasms / pathology
  • Intestinal Mucosa / metabolism*
  • Intestines / pathology*
  • Mice
  • Molecular Sequence Data
  • Peptide Fragments / metabolism
  • Protein Isoforms / chemistry
  • Protein Isoforms / metabolism
  • Substrate Specificity

Substances

  • Antigens, CD
  • Antigens, Differentiation
  • CD66 antigens
  • Carcinoembryonic Antigen
  • Ceacam1 protein, mouse
  • Cell Adhesion Molecules
  • Peptide Fragments
  • Protein Isoforms
  • CASP3 protein, human
  • Casp3 protein, mouse
  • Casp3 protein, rat
  • Caspase 3
  • Caspases