Regulation of Protein Kinase B activity by β Adrenergic Agonists in Rat Epididymal Fat Cells

2001 ◽  
Vol 29 (3) ◽  
pp. A71-A71
Author(s):  
C. J. Bell ◽  
S. K. Moule
Keyword(s):  
Protein Kinase ◽  
Protein Kinase B ◽  
Fat Cells ◽  
Adrenergic Agonists ◽  
Epididymal Fat

scholarly journals Regulation of Protein Kinase B and Glycogen Synthase Kinase-3 by Insulin and β-Adrenergic Agonists in Rat Epididymal Fat Cells

1997 ◽  
Vol 272 (12) ◽  
pp. 7713-7719 ◽  
Author(s):  
S. Kelly Moule ◽  
Gavin I. Welsh ◽  
Nigel J. Edgell ◽  
Emily J. Foulstone ◽  
Christopher G. Proud ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Glycogen Synthase ◽  
Protein Kinase B ◽  
Glycogen Synthase Kinase ◽  
Glycogen Synthase Kinase 3 ◽  
Fat Cells ◽  
Adrenergic Agonists ◽  
Epididymal Fat

scholarly journals Comparison of the effects of insulin and adrenergic agonists on the phosphorylation of an acid-soluble 22 kDa protein in rat epididymal fat-pads and isolated fat-cells

1992 ◽  
Vol 282 (3) ◽  
pp. 729-736 ◽  
Author(s):  
T A Diggle ◽  
R M Denton
Keyword(s):  
Cyclic Amp ◽  
Phorbol Esters ◽  
Protein Composition ◽  
Fat Cells ◽  
Adrenergic Agonists ◽  
Beta Adrenergic ◽  
Epididymal Fat ◽  
Apparent Homogeneity ◽  
Sds Page ◽  
Fat Pads

1. Earlier studies have shown that exposure of fat-cells to insulin results in the rapid increased phosphorylation of an acid-soluble 22 kDa protein and that increases in phosphorylation were also evident in cells exposed to adrenaline [Belsham & Denton (1980) Biochem. Soc. Trans. 8, 382-383; Belsham, Brownsey, Hughes & Denton (1980) Diabetologia 18, 307-312]. 2. The effects of adrenaline are shown to be brought about through beta-adrenergic receptors and to be mimicked by other agents which increase cell cyclic AMP concentrations. The maximum extent of phosphorylation is about 60% of that observed with insulin. Increased phosphorylation is also observed in fat-cells exposed to vasopressin, oxytocin and phorbol esters, but not to alpha-adrenergic agonists. 3. No changes in the phosphorylation of the protein are evident in epididymal fat-pads from fat-fed, starved or starved/refed animals, despite the large changes in protein composition of fat-cells which accompany these nutritional alterations. This suggests that the protein is not closely involved in lipogenesis or associated metabolic pathways, but rather that it may play a more general regulatory role. 4. The 22 kDa protein migrates as a doublet on SDS/PAGE even after purification to apparent homogeneity by sequential use of Mono Q chromatography, SDS/PAGE and h.p.l.c. The amino acid compositions of the two components are very similar and share features in common with a number of proteins, including inhibitor-1, inhibitor-2, dopamine- and cyclic-AMP-regulated phosphoprotein (DARPP-32), and G-substrate, which may be involved in the regulation of protein phosphatase activity. 5. Phosphopeptide mapping and phosphoamino acid analysis reveals that insulin increases the phosphorylation of two distinct peptides within the protein (in one peptide insulin increases the amount of phosphothreonine, whereas in the other the hormone increases the amounts of phosphothreonine and phosphoserine). Both components of the doublet exhibit similar changes in phosphorylation, and hence the differences in migration are not the result of differences in phosphorylation, as suggested previously [Blackshear, Nemenoff & Avruch (1983) Biochem. J. 214, 11-19]. The pattern of phosphorylation observed with the beta-adrenergic agonist isoprenaline was similar to that observed with insulin. 6. The possible role and regulation of the 22 kDa protein are discussed.

Protein kinase in rat adipocytes: influence of androgenic status and regional fat distribution

1993 ◽  
Vol 138 (3) ◽  
pp. 493-501 ◽  
Author(s):  
D. Lacasa ◽  
B. Agli ◽  
B. Mur ◽  
M. N. Dieudonné ◽  
Y. Giudicelli
Keyword(s):  
Protein Kinase ◽  
Specific Binding ◽  
Fat Distribution ◽  
Fat Cells ◽  
Testosterone Treatment ◽  
Epididymal Fat ◽  
Fat Deposits ◽  
The Difference ◽  
Regional Fat Distribution

ABSTRACT The effects of castration and testosterone treatment on insulin- and phorbol ester (TPA)-stimulated lipogenic responses, phorbol dibutyrate-specific binding to protein kinase C (PKC) in the cytosol and the β-PKC isoform level quantified by immunoblotting were compared in rat fat cells from femoral subcutaneous (SC) and deep intra-abdominal (epididymal) fat deposits. In control rats, the PKC content was lower in SC than in epididymal fat cells. After castration, the difference in PKC content between SC and epididymal fat cells was reduced and restored by testosterone treatment. However, androgenic status failed to modify the PKC content in SC fat cells. The lipogenic response to insulin was also differently regulated by the androgenic status in the two fat deposits. After castration, the response was increased in SC fat cells, while it was blunted in epididymal fat cells. These effects were corrected by testosterone administration. These results demonstrate that, in white adipocytes, PKC is an additional biological parameter which varies according to the anatomical origin of the fat cells. They also provide evidence that PKC is controlled by androgens in vivo and emphasize the regional site specificity of such a control. Journal of Endocrinology (1993) 138, 493–501

A role for the actin cytoskeleton in the hormonal and growth-factor-mediated activation of protein kinase B

2001 ◽  
Vol 353 (3) ◽  
pp. 735
Author(s):  
K. PEYROLLIER ◽  
E. HAJDUCH ◽  
A. GRAY ◽  
G. J. LITHERLAND ◽  
A. R. PRESCOTT ◽  
...  
Keyword(s):  
Growth Factor ◽  
Protein Kinase ◽  
Actin Cytoskeleton ◽  
Protein Kinase B
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