TY - JOUR
T1 - Epidermal growth factor-mediated inhibition of neurotransmitter glutamate release from rat forebrain synaptosomes
AU - Barrie, Anne
AU - Chieregatti, Evelina
AU - Miloso, Mariarosaria
AU - Benfenati, Fabio
AU - Valtorta, Flavia
PY - 1996/3
Y1 - 1996/3
N2 - We investigated the possibility that receptor tyrosine kinases are involved in modulating neurotransmitter release from isolated nerve terminals. We examined the effects of epidermal growth factor on the release of neurotransmitter glutamate evoked from rat forebrain synaptosomes by KCl and 4-aminopyridine. We detected a significant inhibition of the Ca2+- dependent component of release. This effect appears to be mediated by a reduction in the depolarization-evoked increase in cytosolic free calcium levels, in the absence of significant effects on the plasma membrane potential. On depolarization, a Ca2+-dependent increase was observed in the phosphotyrosine content of bands at molecular masses of ~107 and ~40 kDa. The addition of epidermal growth factor before depolarization induced a significant phosphorylation of the growth factor receptor in the absence of detectable changes in the phosphotyrosine pattern of total synaptosomal proteins, suggesting that phosphorylation of a minor protein is responsible for the epidermal growth factor-mediated inhibition of glutamate release.
AB - We investigated the possibility that receptor tyrosine kinases are involved in modulating neurotransmitter release from isolated nerve terminals. We examined the effects of epidermal growth factor on the release of neurotransmitter glutamate evoked from rat forebrain synaptosomes by KCl and 4-aminopyridine. We detected a significant inhibition of the Ca2+- dependent component of release. This effect appears to be mediated by a reduction in the depolarization-evoked increase in cytosolic free calcium levels, in the absence of significant effects on the plasma membrane potential. On depolarization, a Ca2+-dependent increase was observed in the phosphotyrosine content of bands at molecular masses of ~107 and ~40 kDa. The addition of epidermal growth factor before depolarization induced a significant phosphorylation of the growth factor receptor in the absence of detectable changes in the phosphotyrosine pattern of total synaptosomal proteins, suggesting that phosphorylation of a minor protein is responsible for the epidermal growth factor-mediated inhibition of glutamate release.
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M3 - Article
C2 - 8643078
AN - SCOPUS:0029968294
VL - 49
SP - 399
EP - 403
JO - Molecular Pharmacology
JF - Molecular Pharmacology
SN - 0026-895X
IS - 3
ER -