Immunocytochemical evaluation of protein kinase C translocation to the inner nuclear matrix in 3T3 mouse fibroblasts after IGF-I treatment

1995 ◽  
Vol 103 (6) ◽  
pp. 447-457 ◽  
Author(s):  
N. Zini ◽  
A. M. Martelli ◽  
L. M. Neri ◽  
A. Bavelloni ◽  
P. Sabatelli ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Nuclear Matrix ◽  
Mouse Fibroblasts ◽  
Kinase C ◽  
Igf I

scholarly journals Phosphatidylinositol 3-Kinase Is a Requirement for Insulin-Like Growth Factor I-Induced Differentiation, but not for Mitogenesis, in Fetal Brown Adipocytes

1997 ◽  
Vol 11 (5) ◽  
pp. 595-607 ◽  
Author(s):  
Angela M. Valverde ◽  
Margarita Lorenzo ◽  
Paloma Navarro ◽  
Manuel Benito
Keyword(s):  
Protein Kinase C ◽  
Growth Factor ◽  
Protein Kinase ◽  
Signaling Pathways ◽  
Brown Adipocyte ◽  
Phosphatidylinositol 3 Kinase ◽  
Brown Adipocytes ◽  
Factor I ◽  
Kinase C ◽  
Igf I

Abstract In the present study we have examined the role of phosphatidylinositol 3-kinase (PI 3-kinase) in the insulin-like growth factor I (IGF-I)-signaling pathways involved in differentiation and in mitogenesis in fetal rat brown adipocytes. Activation of PI 3-kinase in response to IGF-I was markedly inhibited by two PI 3-kinase inhibitors (wortmannin and LY294002) in a dose-dependent manner. IGF-I-stimulated glucose uptake was also inhibited by both compounds. The expression of adipogenic-related genes such as fatty acid synthase, malic enzyme, glycerol 3-phosphate dehydrogenase, and acetylcoenzyme A carboxylase induced by IGF-I was totally prevented in the presence of IGF-I and any of those inhibitors, resulting in a marked decrease of the cytoplasmic lipid content. Moreover, the expression of the thermogenic marker uncoupling protein induced by IGF-I was also down-regulated in the presence of wortmannin/LY294002. IGF-I-induced adipogenic- and thermogenic-related gene expression was only partly inhibited by the p70S6k inhibitor rapamycin. In addition, pretreatment of brown adipocytes with either wortmannin or LY294002, but not with rapamycin, blocked protein kinase C ζ activation by IGF-I. In contrast, IGF-I-induced fetal brown adipocyte proliferation was PI 3-kinase-independent. Our results show for the first time an essential requirement of PI 3-kinase in the IGF-I-signaling pathways leading to fetal brown adipocyte differentiation, but not leading to mitogenesis. In addition, protein kinase C ζ seems to be a signaling molecule also involved in the IGF-I differentiation pathways downstream from PI 3-kinase.

scholarly journals Selective nuclear translocation of protein kinase C α in Swiss 3T3 cells treated with IGF-I, PDGF and EGF

FEBS Letters ◽  
1994 ◽  
Vol 347 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Luca M. Neri ◽  
Anna Maria Billi ◽  
Lucia Manzoli ◽  
Silvia Rubbini ◽  
R.Stewart Gilmour ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Nuclear Translocation ◽  
3T3 Cells ◽  
Kinase C ◽  
Igf I ◽  
Swiss 3T3

scholarly journals Insulin-like effects of epidermal growth factor and insulin-like growth factor-I on [3H]2-deoxyglucose uptake, diacylglycerol generation and protein kinase C activation in BC3H-1 myocytes

1989 ◽  
Vol 261 (3) ◽  
pp. 927-934 ◽  
Author(s):  
R V Farese ◽  
G P Nair ◽  
C G Sierra ◽  
M L Standaert ◽  
R J Pollet ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Growth Factor ◽  
Protein Kinase ◽  
Epidermal Growth Factor ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Kinase C ◽  
Igf I ◽  
Epidermal Growth ◽  
Hydrolysis Of

Epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I) were found to provoke increases in [3H]2-deoxyglucose uptake, diacylglycerol (DAG) generation and membrane-bound protein kinase C activity in BC3H-1 myocytes. These effects were similar to those provoked by insulin. The increases in DAG did not appear to be derived from hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) or phosphatidylinositol, but may have been derived from synthesis of phosphatidic acid de novo, and hydrolysis of phosphatidylcholine, as revealed by studies with [3H]glycerol and [3H]choline respectively. Accordingly, both EGF and IGF-I increased acute [3H]glycerol labelling of DAG (and other lipids) and [3H]choline labelling of phosphocholine. These labelling responses were similar in time course, suggesting that they are closely coupled. Our findings suggest that EGF and IGF-I, like insulin, increase DAG-protein kinase C signalling, apparently by activating co-ordinated lipid-synthesis and -hydrolysis responses, which are distinctly different from the PIP2-hydrolysis response.

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