CELL-ADHESION ACTIVITY OF THE SHORT CYTOPLASMIC DOMAIN ISOFORM OF C-CAM (C-CAM2) IN CHO CELLS

C-CAM is a Ca2+-independent rat cell adhesion molecule belonging to th e CEA gene family of!the immunoglobulin superfamily. Two major isoform s that differ in the length of their cytoplasmic domains exist, In pre vious studies it has been reported that only the long isoform (C-CAM1) but not the short isoform (C-CAM2) can mediate adhesion, However, in the mouse, isoforms with both long and short cytoplasmic domains have been reported to have adhesive activity. In order to analyze this appa rent conflict we transfected C-CAM1 or C-CAMZ into CHO Pro5 cells and examined their adhesive phenotype in an aggregation assay. We found th at in this cellular system both C-CAM1 and C-CAM2 could mediate cell-c ell adhesion in a Ca2+-independent and temperature-independent way. Th e results suggest that the cellular environment is important for the a ctivity of C-CAM isoforms.