scholarly journals Insulin-like Growth Factor I Receptor Does Not Contribute to Heat Shock-induced Activation of Akt and Extracellular Signal-regulated Kinase (ERK) in Mouse Embryo Fibroblasts

2004 ◽  
Vol 45 (1) ◽  
pp. 141-144 ◽  
Author(s):  
Keiko KATAOKA ◽  
Masahiko MIURA
Keyword(s):  
Growth Factor ◽  
Heat Shock ◽  
Mouse Embryo ◽  
Insulin Like Growth Factor ◽  
Extracellular Signal Regulated Kinase ◽  
Factor I ◽  
Mouse Embryo Fibroblasts ◽  
Extracellular Signal ◽  
Growth Factor I ◽  
Embryo Fibroblasts

scholarly journals Insulin-like growth factor I receptor signaling in transformation by src oncogenes.

1997 ◽  
Vol 17 (7) ◽  
pp. 3744-3754 ◽  
Author(s):  
B Valentinis ◽  
A Morrione ◽  
S J Taylor ◽  
R Baserga
Keyword(s):  
Growth Factor ◽  
Mouse Embryo ◽  
Soft Agar ◽  
Insulin Like Growth Factor ◽  
Full Transformation ◽  
Factor I ◽  
Mouse Embryo Fibroblasts ◽  
Igf I ◽  
Growth Factor I ◽  
Embryo Fibroblasts

R- cells, a line of mouse embryo fibroblasts with a targeted disruption of the insulin-like growth factor I (IGF-I) receptor genes, are refractory to transformation by several viral and cellular oncogenes. Using colony formation in soft agar as a measure of full transformation, we report here that R- cells can be transformed by v-src, although they still cannot be transformed by the activated c-src527 (mutation at tyrosine 527 to phenylalanine), which readily transforms mouse embryo cells with a wild-type number of IGF-I receptors (W cells). Although v-src is a more potent inducer of tyrosine phosphorylation than c-src527, the extent of phosphorylation of either insulin receptor substrate 1 or Shc, two of the major substrates of the IGF-I receptor, does not seem sufficiently different to explain the qualitative difference in soft agar growth. v-src, however, is considerably more efficient than c-src527 in its ability to tyrosyl phosphorylate, in R- cells, the focal adhesion kinase, Stat1, and p130cas. These results indicate that v-src, but not c-src527, can bypass the requirement for a functional IGF-I receptor in the full transformation of mouse embryo fibroblasts and suggest that qualitative and quantitative differences between the two oncogenes can be used to identify some of the signals relevant to the mechanism(s) of transformation.

scholarly journals Transformation of Late Passage Insulin-Like Growth Factor-I Receptor Null Mouse Embryo Fibroblasts by SV40 T Antigen

2006 ◽  
Vol 66 (8) ◽  
pp. 4233-4239 ◽  
Author(s):  
Susan L. Spence ◽  
Arthur L. Shaffer ◽  
Louis M. Staudt ◽  
Sewit Amde ◽  
Sutana Manney ◽  
...  
Keyword(s):  
Growth Factor ◽  
Mouse Embryo ◽  
T Antigen ◽  
Null Mouse ◽  
Insulin Like Growth Factor ◽  
Sv40 T Antigen ◽  
Factor I ◽  
Mouse Embryo Fibroblasts ◽  
Late Passage ◽  
Growth Factor I

scholarly journals Phosphorylation of Nuclear Phospholipase C β1 by Extracellular Signal-Regulated Kinase Mediates the Mitogenic Action of Insulin-Like Growth Factor I

2001 ◽  
Vol 21 (9) ◽  
pp. 2981-2990 ◽  
Author(s):  
Aimin Xu ◽  
Pann-Ghill Suh ◽  
Nelly Marmy-Conus ◽  
Richard B. Pearson ◽  
Oh Yong Seok ◽  
...  
Keyword(s):  
Growth Factor ◽  
Phospholipase C ◽  
Critical Role ◽  
Insulin Like Growth Factor ◽  
Extracellular Signal Regulated Kinase ◽  
Factor I ◽  
Extracellular Signal ◽  
Mitogenic Action ◽  
Igf I ◽  
Growth Factor I

ABSTRACT It is well established that a phosphoinositide (PI) cycle which is operationally distinct from the classical plasma membrane PI cycle exists within the nucleus, where it is involved in both cell proliferation and differentiation. However, little is known about the regulation of the nuclear PI cycle. Here, we report that nucleus-localized phospholipase C (PLC) β1, the key enzyme for the initiation of this cycle, is a physiological target of extracellular signal-regulated kinase (ERK). Stimulation of Swiss 3T3 cells with insulin-like growth factor I (IGF-I) caused rapid nuclear translocation of activated ERK and concurrently induced phosphorylation of nuclear PLC β1, which was completely blocked by the MEK inhibitor PD 98059. Coimmunoprecipitation detected a specific association between the activated ERK and PLC β1 within the nucleus. In vitro studies revealed that recombinant PLC β1 could be efficiently phosphorylated by activated mitogen-activated protein kinase but not by PKA. The ERK phosphorylation site was mapped to serine 982, which lies within a PSSP motif located in the characteristic carboxy-terminal tail of PLC β1. In cells overexpressing a PLC β1 mutant in which serine 982 is replaced by glycine (S982G), IGF-I failed to activate the nuclear PI cycle, and its mitogenic effect was also markedly attenuated. Expression of S982G was found to inhibit ERK-mediated phosphorylation of endogenous PLC β1. This result suggests that ERK-evoked phosphorylation of PLC β1 at serine 982 plays a critical role in the activation of the nuclear PI cycle and is also crucial to the mitogenic action of IGF-I.

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