Neuronal growth factor regulation of two different sodium channel types through distinct signal transduction pathways.
Neuronal growth factors regulate the expression of voltage-activated sodium current in differentiating sympathetic neurons and PC12 cells. We show that, in PC12 cells, the NGF- and FGF-induced sodium current results from increased expression of two distinct sodium channel types. Sodium current results from the rapid induction of a novel sodium channel transcript, also found in peripheral neurons, and from the long term induction of brain type II/IIA mRNA. Expression of the type II/IIA sodium channel requires activation of the cyclic AMP-dependent protein kinase (A-kinase), whereas induction of the peripheral neuron type sodium channel occurs through an A-kinase-independent signal transduction pathway. These findings suggest that the two sodium channel types act in concert to ensure the generation of action potentials during neuronal differentiation.
Department of Neurobiology and Behavior, State University of New York, Stony Brook 11794-5230.
G
G
D'Arcangelo
K
K
Paradiso
D
D
Shepherd
P
P
Brehm
S
S
Halegoua
G
G
Mandel
D000818:Animals; D000242:Cyclic AMP / Q000502:physiology; D005346:Fibroblast Growth Factors / Q000494:pharmacology*; D015870:Gene Expression; D066298:In Vitro Techniques; D008564:Membrane Potentials; D009414:Nerve Growth Factors / Q000502:physiology*; D016716:PC12 Cells; D011494:Protein Kinases / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D015398:Signal Transduction; D012964:Sodium / Q000502:physiology; D015222:Sodium Channels / Q000502:physiology*; D013997:Time Factors; D014158:Transcription, Genetic
D009414:Nerve Growth Factors; D012333:RNA, Messenger; D015222:Sodium Channels; D005346:Fibroblast Growth Factors; D012964:Sodium; D000242:Cyclic AMP; D011494:Protein Kinases