BOTH P140(TRK) AND P75(NGFR) NERVE GROWTH-FACTOR RECEPTORS MEDIATE NERVE GROWTH FACTOR-STIMULATED CALCIUM-UPTAKE

Human p140(trk) and p75(NGFR) were transfected separately into 3T3 cel ls. Nerve growth factor stimulates calcium uptake into both transfecta nts but not into untransfected 3T3 cells. p140(trk) cells were stimula ted maximally by 25 ng/ml; 100 ng/ml was submaximal for p75(NGFR) cell s. K-252a inhibits the effect of NGF on p140(trk) cells but not on p75 (NGFR) cells; brain-derived neurotrophic factor stimulates calcium upt ake in p75(NGFR) cells but not in p140(trk) cells. The data suggest th at both nerve growth factor receptors could be involved in the nerve g rowth factor-mediated actions of calcium on its target cells: neuronal survival, neuronal protection, and synaptic plasticity.