Nr-CAM: a cell adhesion molecule with ligand and receptor functions.
Nr-CAM Ng-CAM-related cell adhesion molecule) is expressed only in the nervous system on a subset of neurons and non-neuronal cells, including floor-plate cells in the spinal cord and Schwann cells. It is a member of the immunoglobulin (Ig) superfamily and can bind by a homophilic mechanism but its heterophilic interactions may be of greater biological significance. Nr-CAM functions as a neuronal receptor for neurite-growth-promoting stimuli provided by contactin/F11, neurofascin, and RPTPbeta. In addition, by binding to neuronal receptors such as axonin-1, it can modulate axonal guidance. Nr-CAM can also interact laterally with contactin/F11 within the plasma membrane in the form of a complex that may transmit signals to regulate axonal growth. This review summarizes the structure and expression of Nr-CAM and discusses its potential functions as a ligand and as a receptor during neural development.
Grumet
M
M
Department of Pharmacology, New York University Medical Center, 550 First Avenue, New York, NY 10016, USA. grumem01@mcrcr6.med.nyu.edu
D000818:Animals; D015815:Cell Adhesion Molecules; D015816:Cell Adhesion Molecules, Neuronal / Q000502:physiology*; D006801:Humans; D008024:Ligands; D009420:Nervous System / Q000196:embryology*; D009424:Nervous System Physiological Phenomena; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic
D015815:Cell Adhesion Molecules; D015816:Cell Adhesion Molecules, Neuronal; D008024:Ligands; C491152:NRCAM protein, human; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic