Signal transduction by nerve growth factor and fibroblast growth factor in PC12 cells requires a sequence of src and ras actions.

Abstract

Abstract. We have investigated the roles of pp60-src and p21-proteins in transducing the nerve growth factor (NGF) and fibroblast growth factor (FGF) signals which promote the sympathetic neuronlike phenotype in PC12 cells. Neutralizing antibodies directed against either Src or Ras proteins were microinjected into fused PC12 cells. Each antibody both prevented and reversed NGF-or FGF-induced neurite growth, a prominent morphological marker for the neuronal phenotype . These data demonstrate the involvement of both pp60--and p21--proteins in NGF and FGF actions in PC12 cells, and establish a physiological role for the pp60c-s-tyrosine kinase in signal transduction pathways initiated by receptor tyrosine kinases in these cells . Additional microinjection experiments, N ERVE growth factor (NGF)l (39) and fibroblast growth factor (FGF) (for review see reference 70) are neuronal growth factors which mediate survival and differentiation ofmany types ofneurons in vivo and in primary neuronal cultures. Application ofNGF or FGF to cells ofthe clonal rat pheochromocytoma cell line, PC12, engages a program ofphysiological changes, resulting in a phenotype resembling that of sympathetic neurons . These changes include neurite outgrowth, establishment ofa sodium-based action potential, induction of a variety ofbiochemically defined neuronal characteristics, and the cessation of cell division (see reference 18) . The PC12 cell line has thus been a useful model system for studying the intracellular events associated with growth factor-induced neuronal differentiation .The signal transduction pathways used by NGF to accomplish these changes have been extensively studied but are only partially understood. Underlying the physiological changes brought about by NGF and FGF is a coordinated sequence of posttranslational modifications and changes in gene expression that occur throughout persistent treatment with the growth factor (for review see reference 23) . Several 1. Abbreviations used in this paper: FGF, fibroblast growth factor ; GAP, GTPase activating protein ; MMTV, mouse mammary tumor virus; NGF, nerve growth factor. © The Rockefeller University Press, 0021-9525/91/11/809/11 $2.00 TheJournal of Cell Biology, Volume 115, Number 3, November 1991809-819 using PC12 transfectants containing inducible v-src or ras oncogene activities, demonstrated a specific sequence of Src and Ras actions . Microinjection of antiRas antibody blocked v-src-induced neurite growth, but microinjection of anti-Src antibodies had no effect on ras oncogene-induced neurite growth . We propose that a cascade of Src and Ras actions, with Src acting first, is a significant feature of the signal transduction pathways for NGF and FGF The Src -Ras cascade may define a functional cassette in the signal transduction pathways used by growth factors and other ligands whose receptors have diverse structures and whose range of actions on various cell types include mitogenesis and differentiation . second messenger pathways have been implicated in NGF action includi...

APRO4 negatively regulates Src tyrosine kinase activity in PC12 cells

“…This activation which lasts around 12 hours is consistent with previously reported data showing that stimulation of Src and Ras/MAP kinase signalling cascade is an early event in FGF signal transduction pathway (Kremer et al, 1991) and that a sustained MAP kinase activity is required for FGF-mediated PC12 neuronal differentiation (Qui and Green, 1992). During this time, the amount of endogenous APRO4 protein co-immunoprecipitated with Src is very low.…”

FRS2-dependent SRC activation is required for fibroblast growth factor receptor-induced phosphorylation of Sprouty and suppression of ERK activity

“…SRC has been implicated in FGFR-induced neurite outgrowth (Kremer et al, 1991), is required for cell migration and shape changes induced by FGFR (Liu et al, 1999) and is a necessary component for FGFR1 signal transduction in Xenopus (Browaeys-Poly et al, 2000). The SFKs, XFyn and Laloo, are required for FGF-induced mesoderm induction during Xenopus early development (Weinstein et al, 1998;Hama et al, 2001;Kusakabe et al, 2001;Weinstein and Hemmati-Srivanlou, 2001).…”

KSR and CNK: two scaffolds regulating RAS-mediated RAF activation

“…If this interaction is inhibitory to B-RAF, it would be interesting to verify whether a Src-binding mechanism analogous to the one described in Drosophila releases inhibition. The PC12 cell model might be appropriate to explore this possibility as their NGF-induced differentiation depends on Src, B-RAF and CNK2 (Kremer et al, 1991;Vaillancourt et al, 1994;Bumeister et al, 2004).…”