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

Moule, S K; Welsh, Gavin I.; Edgell, Nigel J.; Foulstone, Emily J.; Proud, Christopher G.; Denton, Richard M.

doi:10.1074/jbc.272.12.7713

Cited by 229 publications

(184 citation statements)

References 43 publications

Supporting

Mentioning

168

Contrasting

Order By: Relevance

“…Since most physiological agonists that elevate cAMP levels also strongly activate PI-3K, it is still unclear as to the relevance of these observations. Finally, in rat epididymal fat cells, isoprenaline (' isoproterenol ') (acting through α $ -adrenoreceptors), but not cAMP analogues, increases the activity of PKB, although to a lesser extent than insulin [42]. In this system wortmannin abolishes PKB activation by insulin, but has no effect on the activation seen in response to isoprenaline.…”

Section: Phosphatidylinositol 3-kinase (Pi-3k) Mediates Pkb Activationmentioning

confidence: 96%

Protein kinase B (c-Akt): a multifunctional mediator of phosphatidylinositol 3-kinase activation

Coffer

Jin

Woodgett

1998

Biochemical Journal

985

817

View full text Add to dashboard Cite

While a plethora of extracellular molecules exist that modulate cellular functions via binding to membrane receptors inside the cell, their actions are mediated by relatively few signalling mechanisms. One of these is activation of phosphatidylinositol 3-kinase (PI-3K), which results in the generation of a membranerestricted second messenger, polyphosphatidylinositides containing a 3h-phosphate. How these molecules transduced the effects of agonists of PI-3K was unclear until the recent discovery that several protein kinases become activated upon exposure to 3h-phosphorylated inositol lipids. These enzymes include protein kinase B (PKB)\AKT and PtdIns(3,4,5)P $ -dependent kinases 1 and 2, the first two of which interact with 3h-phosphorylated ORIGINS OF AKTThe AKR strain of mice exhibit a high incidence of leukaemias and lymphomas from spontaneous thymoma [1]. A retrovirus termed AKT8 was isolated from one of these lines derived from a spontaneous thymoma. This virus was demonstrated to uniquely transform only mink lung cells (CCL64) in culture, while virus inoculated into newborn mice was shown to be tumorigenic [2]. The non-viral DNA component transduced from the mouse genome was subsequently identified, and two human homologues, AKT1 and AKT2, cloned [3]. The location of the human AKT locus was mapped to chromosome 14q32, proximal to the immunoglobulin-heavy-chain locus [4], a region frequently affected by translocations and inversions in human Tcell leukaemia\lymphoma, mixed-lineage childhood leukaemia and clonal T-cell proliferations in ataxia telangiectasia, supporting a role for this oncogene in formation of a variety of tumours [5]. Analysis of a panel of human tumours revealed a 20-fold amplification of AKT1 in a primary gastric adenocarcinoma. AKT2, on the other hand, was mapped to chromosome region 19q13.1-q13.2 and shown to be amplified and overexpressed in several ovarian carcinoma and pancreatic cancer cell lines [6,7]. A recent large-scale study of AKT2 alterations in ovarian and breast tumours revealed amplification in 12.1 % ovarian and 2.8 % breast carcinomas [8]. Furthermore, amplification of AKT2 was especially frequent in undifferentiated tumours, suggesting that AKT2 alterations may be associated with tumour aggressiveness.Abbreviations used : PI-3K, phosphatidylinositol 3-kinase ; PKB, protein kinase B ; PKA, protein kinase A ; PKC, protein kinase C ; RAC-PK, related to A-and C-kinase ; PH, pleckstrin homology ; PtdIns, phosphoinositide ; PDGF, platelet-derived growth factor ; EGF, epidermal growth factor ; bFGF, basic fibroblast growth factor ; IL, interleukin ; ERK, extracellular-signal-regulated kinase ; Btk, Bruton tyrosine kinase ; PDK, PtdIns(3,4,5)P 3 -dependent kinase ; MAPKAP, mitogen-activated protein kinase-activated protein ; SH2, Src homology 2 ; gag, group-specific antigen ; GLUT, glucose transporter ; GSK, glycogen synthase kinase ; PFK2, 6-phosphofructose-2-kinase ; IGF, insulin-like growth factor ; 4E-BP1, 4E-binding protein ; PHAS, pH-and acid-stable ; BCR-ABL, breakpoint...

show abstract

Section: Phosphatidylinositol 3-kinase (Pi-3k) Mediates Pkb Activationmentioning

confidence: 96%

Protein kinase B (c-Akt): a multifunctional mediator of phosphatidylinositol 3-kinase activation

Coffer

Jin

Woodgett

1998

Biochemical Journal

985

817

View full text Add to dashboard Cite

show abstract

“…Immunoprecipitation with anti-PKB-CT Ab (50 l/10 g IgG) was conducted for 2 h at room temperature or overnight at 4°C, as described above, and washed proteins were suspended in 30 -40 l of reaction buffer (20 mM HEPES, pH 7.4, 1 mM DTT, 10 mM MnCl 2 , 10 mM MgCl 2 , 5 M ATP, 10 Ci [␥-32 P]ATP, 5 M cAMP protein kinase inhibitor) containing either 13 g of K9 peptide (KKRNRTLTK), 1 g of Crosstide (GRPRTSSFAEG), or 2.5 g of histone-2B (Boehringer Mannheim) as substrate (17,35,36). As recently described (26), after incubation for 15 min at 30°C, assay reactions with K9 or Crosstide peptides were terminated by addition of 10 l of 1% BSA, 1 mM ATP, pH 3, and 5 l of 30% TCA.…”

Section: Pkb Assays With Crosstide K9 Peptide and Histone 2b Substrmentioning

confidence: 99%

Cyclic Nucleotide Phosphodiesterase 3B Is a Downstream Target of Protein Kinase B and May Be Involved in Regulation of Effects of Protein Kinase B on Thymidine Incorporation in FDCP2 Cells

Ahmad

Cong

Stenson

et al. 2000

The Journal of Immunology

View full text Add to dashboard Cite

Wild-type (F/B), constitutively active (F/B*), and three kinase-inactive (F/Ba−, F/Bb−, F/Bc−) forms of Akt/protein kinase B (PKB) were permanently overexpressed in FDCP2 cells. In the absence of insulin-like growth factor-1 (IGF-1), activities of PKB, cyclic nucleotide phosphodiesterase 3B (PDE3B), and PDE4 were similar in nontransfected FDCP2 cells, mock-transfected (F/V) cells, and F/B and F/B− cells. In F/V cells, IGF-1 increased PKB, PDE3B, and PDE4 activities ∼2-fold. In F/B cells, IGF-1, in a wortmannin-sensitive manner, increased PKB activity ∼10-fold and PDE3B phosphorylation and activity (∼4-fold), but increased PDE4 to the same extent as in F/V cells. In F/B* cells, in the absence of IGF-1, PKB activity was markedly increased (∼10-fold) and PDE3B was phosphorylated and activated (3- to 4-fold); wortmannin inhibited these effects. In F/B* cells, IGF-1 had little further effect on PKB and activation/phosphorylation of PDE3B. In F/B− cells, IGF-1 activated PDE4, not PDE3B, suggesting that kinase-inactive PKB behaved as a dominant negative with respect to PDE3B activation. Thymidine incorporation was greater in F/B* cells than in F/V cells and was inhibited to a greater extent by PDE3 inhibitors than by rolipram, a PDE4 inhibitor. In F/B cells, IGF-1-induced phosphorylation of the apoptotic protein BAD was inhibited by the PDE3 inhibitor cilostamide. Activated PKB phosphorylated and activated rPDE3B in vitro. These results suggest that PDE3B, not PDE4, is a target of PKB and that activated PDE3B may regulate cAMP pools that modulate effects of PKB on thymidine incorporation and BAD phosphorylation in FDCP2 cells.

show abstract

“…In other studies β-adrenergic activation causes phosphorylation of GSK3 in cardiac myocytes [37] and epididymal fat cells [21]. We have shown before that β-adrenoceptors increase glucose uptake via cyclic AMP but also via PI3K [24,26], and it is possible that adrenergic receptors affect glycogen content in different ways.…”

Section: Discussionmentioning

confidence: 76%

“…In rat epididymal fat cells, β-adrenoceptors, but not α-adrenoceptors increase glycogen synthesis [20]. In the same cells, β-adrenoceptors decrease GSK3 activity leading to increased glycogen, a process that cannot be mimicked by activation of cyclic AMP signalling [21]. And finally, β-adrenergic-mediated GSK3 phosphorylation is also seen in a fibroblast like cell line [7].…”

Section: Introductionmentioning

confidence: 99%

β2-Adrenergic activation increases glycogen synthesis in L6 skeletal muscle cells through a signalling pathway independent of cyclic AMP

2006

View full text Add to dashboard Cite

Aims/hypothesis In skeletal muscle, the storage of glycogen by insulin is regulated by glycogen synthase, which is regulated by glycogen synthase kinase 3 (GSK3). Here we examined whether adrenergic receptor activation, which can increase glucose uptake, regulates glycogen synthesis in L6 skeletal muscle cells. Methods We used L6 cells and measured glycogen synthesis (as incorporation of D-[U-14 C]glucose into glycogen) and GSK3 phosphorylation following adrenergic activation. Results Insulin (negative logarithm of median effective concentration [pEC 50 ] 8.2± 0.3) and the β-adrenergic agonist isoprenaline (pEC 50 7.5±0.3) induced a twofold increase in glycogen synthesis in a concentration-dependent manner. The α 1 -adrenergic agonist cirazoline and α 2 -adrenergic agonist clonidine had no effect. Both insulin and isoprenaline phosphorylated GSK3. The β-adrenergic effect on glycogen synthesis is mediated by β 2 -adrenoceptors and not β 1 -/β 3 -adrenoceptors, and was not mimicked by 8-bromo-cyclic AMP or cholera toxin, and also was insensitive to pertussis toxin, indicating no involvement of cyclic AMP or inhibitory G-protein (G i ) signalling in the β 2 -adrenergic effect on glycogen synthesis. 12-O-tetradecanoylphorbol-13-acetate (TPA) increased glycogen synthesis 2.5-fold and phosphorylated GSK3 fourfold.Inhibition of protein kinase C (PKC) isoforms with 12-(2-cyanoethyl)-6,7,12,13-tetrahydro-13-methyl-5-oxo-5H-indolo(2,3-a)pyrrollo(3,4-c)-carbazole (Gö6976; inhibits conventional and novel PKCs) or 2-[1-(3-dimethylaminopropyl)-5-methoxyindol-3-yl]-3-(1H-indol-3-yl)maleimide (Gö6983; inhibits conventional, novel and atypical PKCs) inhibited the stimulatory TPA effect, but did not significantly inhibit glycogen synthesis mediated by insulin or isoprenaline. Inhibition of phosphatidylinositol 3-kinase (PI3K) with wortmannin inhibited the effects of insulin and isoprenaline on glycogen synthesis. Conclusions/interpretation These results demonstrate that in L6 skeletal muscle cells adrenergic stimulation through β 2 -adrenoceptors, but not involving cyclic AMP or G i , activates a PI3K pathway that stimulates glycogen synthesis through GSK3.

show abstract

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

Cited by 229 publications

References 43 publications

Protein kinase B (c-Akt): a multifunctional mediator of phosphatidylinositol 3-kinase activation

Protein kinase B (c-Akt): a multifunctional mediator of phosphatidylinositol 3-kinase activation

Cyclic Nucleotide Phosphodiesterase 3B Is a Downstream Target of Protein Kinase B and May Be Involved in Regulation of Effects of Protein Kinase B on Thymidine Incorporation in FDCP2 Cells

β2-Adrenergic activation increases glycogen synthesis in L6 skeletal muscle cells through a signalling pathway independent of cyclic AMP

Contact Info

Product

Resources

About