NEUROTROPHIN RECEPTORS - MEDIATORS OF LIFE AND DEATH

The mechanism of action of NGF has continued to provide a challenging and formidable problem in signal transduction. NGF can bind independen tly to two different receptors, the trkA tyrosine kinase receptor and the p75 neurotrophin receptor, which are involved in many different si gnaling events. In addition to promoting cell differentiation survival , NGF can paradoxically be an inducer of cell death. Several receptor mediated mechanisms are proposed to explain how NGF might act as a tro phic factor and as a cell killer. The survival and cell death properti es of the receptors are dependent upon the relative ratio of receptors and the persistent nature of the signaling events. (C) 1998 Elsevier Science B.V. All rights reserved.