Turnover studies of the neural cell adhesion molecule NCAM: degradation of NCAM in PC12 cells depends on the presence of NGF.

The neural cell adhesion molecule NCAM is a member of the immunoglobulin superfamily and involved in path finding and outgrowth of neurites in vitro. PC12 cells express two major isoforms of NCAM (NCAM180 and NCAM140) and undergo neuronal differentiation, e.g., neurite formation, in response to NGF. Using this cell system, we determined the half-life time of both NCAM isoforms in the absence and presence of NGF. Half-life time of NCAM140 is similar in the presence and absence of NGF, whereas the half-life time of NCAM180 is increased in the presence of NGF. Furthermore, we quantified protein expression of both NCAM isoforms in the presence or absence of NGF and found a decrease of NCAM protein expression in course of neuronal differentiation.