Requirement for Akt (Protein Kinase B) in Insulin-induced Activation of Glycogen Synthase and Phosphorylation of 4E-BP1 (PHAS-1)*

The roles of Akt (protein kinase B) and the atypical λ isoform of protein kinase C (PKCλ), both of which act downstream of phosphoinositide 3-kinase, in the activation of glycogen synthase and phosphorylation of 4E-BP1 (PHAS-1) in response to insulin were investigated. A mutant Akt (Akt-AA) in which the phosphorylation sites targeted by growth factors are replaced by alanine was shown to inhibit insulin-induced activation of both Akt and glycogen synthase in L6 myotubes. Expression of a mutant Akt in which Lys179 in the kinase domain was replaced by aspartate also inhibited insulin-induced activation of glycogen synthase but had no effect on insulin activation of endogenous Akt. A kinase-defective mutant of PKCλ (λΔNKD), which prevents insulin-induced activation of PKCλ, did not affect the activation of glycogen synthase by insulin. Insulin-induced phosphorylation of 4E-BP1 was inhibited by Akt-AA in Chinese hamster ovary cells. However, λΔNKD had no effect on 4E-BP1 phosphorylation induced by insulin. These data suggest that Akt, but not PKCλ, is required for insulin activation of glycogen synthase and for insulin-induced phosphorylation of 4E-BP1.

[1]  B. Hemmings,et al.  A Human Protein Kinase Bγ with Regulatory Phosphorylation Sites in the Activation Loop and in the C-terminal Hydrophobic Domain* , 1999, The Journal of Biological Chemistry.

[2]  M. Kasuga,et al.  Requirement of Atypical Protein Kinase Cλ for Insulin Stimulation of Glucose Uptake but Not for Akt Activation in 3T3-L1 Adipocytes , 1998, Molecular and Cellular Biology.

[3]  Philip R. Cohen,et al.  Protein kinase C isotypes controlled by phosphoinositide 3-kinase through the protein kinase PDK1. , 1998, Science.

[4]  A. Newton,et al.  Regulation of protein kinase C ζ by PI 3-kinase and PDK-1 , 1998, Current Biology.

[5]  M. Kasuga,et al.  Requirement of the serine-threonine kinase Akt for heat treatment-induced activation of p70 S6 kinase. , 1998, Biochemical and biophysical research communications.

[6]  K. Siddle,et al.  Phosphoinositide 3-kinase: the key switch mechanism in insulin signalling. , 1998, The Biochemical journal.

[7]  J. Olefsky,et al.  Inhibition of Phosphatidylinositol 3-Kinase Activity by Adenovirus-mediated Gene Transfer and Its Effect on Insulin Action* , 1998, The Journal of Biological Chemistry.

[8]  M. Kasuga,et al.  Requirement for Activation of the Serine-Threonine Kinase Akt (Protein Kinase B) in Insulin Stimulation of Protein Synthesis but Not of Glucose Transport , 1998, Molecular and Cellular Biology.

[9]  R. Roth,et al.  Evidence of insulin-stimulated phosphorylation and activation of the mammalian target of rapamycin mediated by a protein kinase B signaling pathway. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[10]  Phillip T. Hawkins,et al.  Translocation of PDK-1 to the plasma membrane is important in allowing PDK-1 to activate protein kinase B , 1998, Current Biology.

[11]  B. Burgering,et al.  Essential Role for Protein Kinase B (PKB) in Insulin-induced Glycogen Synthase Kinase 3 Inactivation , 1998, The Journal of Biological Chemistry.

[12]  M. Birnbaum,et al.  Construction and Characterization of a Conditionally Active Version of the Serine/Threonine Kinase Akt* , 1998, The Journal of Biological Chemistry.

[13]  A. Gingras,et al.  The mRNA 5' cap-binding protein eIF4E and control of cell growth. , 1998, Current opinion in cell biology.

[14]  P. Cohen,et al.  Activation of protein kinase B beta and gamma isoforms by insulin in vivo and by 3-phosphoinositide-dependent protein kinase-1 in vitro: comparison with protein kinase B alpha. , 1998, The Biochemical journal.

[15]  Y. Yazaki,et al.  Potential Role of Protein Kinase B in Insulin-induced Glucose Transport, Glycogen Synthesis, and Protein Synthesis* , 1998, The Journal of Biological Chemistry.

[16]  A. Gingras,et al.  4E-BP1, a repressor of mRNA translation, is phosphorylated and inactivated by the Akt(PKB) signaling pathway. , 1998, Genes & development.

[17]  C. Marshall,et al.  Activation of the Mitogen-Activated Protein Kinase/Extracellular Signal-Regulated Kinase Pathway by Conventional, Novel, and Atypical Protein Kinase C Isotypes , 1998, Molecular and Cellular Biology.

[18]  S. R. Datta,et al.  Akt Phosphorylation of BAD Couples Survival Signals to the Cell-Intrinsic Death Machinery , 1997, Cell.

[19]  A. Gingras,et al.  Adenovirus infection inactivates the translational inhibitors 4E-BP1 and 4E-BP2. , 1997, Virology.

[20]  J. Schlessinger,et al.  Phosphatidylinositol 3-kinase mediates epidermal growth factor-induced activation of the c-Jun N-terminal kinase signaling pathway , 1997, Molecular and cellular biology.

[21]  C. Manthey,et al.  Molecular Cloning and Characterization of a Novel p38 Mitogen-activated Protein Kinase* , 1997, The Journal of Biological Chemistry.

[22]  M. Kasuga,et al.  From receptor to transporter: insulin signalling to glucose transport , 1997, Diabetologia.

[23]  X Wang,et al.  Activation of translation initiation factor eIF2B by insulin requires phosphatidyl inositol 3‐kinase , 1997, FEBS letters.

[24]  David R. Kaplan,et al.  Direct Regulation of the Akt Proto-Oncogene Product by Phosphatidylinositol-3,4-bisphosphate , 1997, Science.

[25]  Robert V Farese,et al.  Activation of Protein Kinase C (α, β, and ζ) by Insulin in 3T3/L1 Cells , 1997, The Journal of Biological Chemistry.

[26]  D. Pot,et al.  A specific product of phosphatidylinositol 3-kinase directly activates the protein kinase Akt through its pleckstrin homology domain , 1997, Molecular and cellular biology.

[27]  M. Birnbaum,et al.  Expression of a Constitutively Active Akt Ser/Thr Kinase in 3T3-L1 Adipocytes Stimulates Glucose Uptake and Glucose Transporter 4 Translocation* , 1996, The Journal of Biological Chemistry.

[28]  P. Cohen,et al.  Mechanism of activation of protein kinase B by insulin and IGF‐1. , 1996, The EMBO journal.

[29]  R. Schneider,et al.  Cap-binding protein (eukaryotic initiation factor 4E) and 4E-inactivating protein BP-1 independently regulate cap-dependent translation , 1996, Molecular and cellular biology.

[30]  S. Grinstein,et al.  Insulin Activates a p21-activated Kinase in Muscle Cells via Phosphatidylinositol 3-Kinase* , 1996, The Journal of Biological Chemistry.

[31]  A. Depaoli-Roach,et al.  Regulation of Both Glycogen Synthase and PHAS-I by Insulin in Rat Skeletal Muscle Involves Mitogen-activated Protein Kinase-independent and Rapamycin-sensitive Pathways (*) , 1996, The Journal of Biological Chemistry.

[32]  Y. Kanegae,et al.  Efficient generation of recombinant adenoviruses using adenovirus DNA-terminal protein complex and a cosmid bearing the full-length virus genome. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[33]  S. Moriya,et al.  EGF or PDGF receptors activate atypical PKClambda through phosphatidylinositol 3‐kinase. , 1996, The EMBO journal.

[34]  S. Moriya,et al.  Platelet-derived growth factor activates protein kinase C epsilon through redundant and independent signaling pathways involving phospholipase C gamma or phosphatidylinositol 3-kinase. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[35]  P. Cohen,et al.  Inhibition of glycogen synthase kinase-3 by insulin mediated by protein kinase B , 1995, Nature.

[36]  M. Diaz-Meco,et al.  Evidence for a role of MEK and MAPK during signal transduction by protein kinase C zeta. , 1995, The EMBO journal.

[37]  M. Kasuga,et al.  Ras-independent and wortmannin-sensitive activation of glycogen synthase by insulin in Chinese hamster ovary cells , 1995, The Journal of Biological Chemistry.

[38]  Y. Yazaki,et al.  Upstream Mechanisms of Glycogen Synthase Activation by Insulin and Insulin-like Growth Factor-I , 1995, The Journal of Biological Chemistry.

[39]  K. Siddle,et al.  Insulin stimulation of glycogen synthesis and glycogen synthase activity is blocked by wortmannin and rapamycin in 3T3-L1 adipocytes: evidence for the involvement of phosphoinositide 3-kinase and p70 ribosomal protein-S6 kinase. , 1995, The Biochemical journal.

[40]  N. Sonenberg,et al.  PHAS-I as a link between mitogen-activated protein kinase and translation initiation. , 1994, Science.

[41]  A. Gingras,et al.  Insulin-dependent stimulation of protein synthesis by phosphorylation of a regulator of 5'-cap function , 1994, Nature.

[42]  T. Haystead,et al.  Phosphorylation of PHAS-I by mitogen-activated protein (MAP) kinase. Identification of a site phosphorylated by MAP kinase in vitro and in response to insulin in rat adipocytes. , 1994, The Journal of biological chemistry.

[43]  F. Grigorescu,et al.  Involvement of phosphoinositide 3‐kinase in insulin‐ or IGF‐1‐induced membrane ruffling. , 1994, The EMBO journal.

[44]  P. Cohen,et al.  The role of protein phosphorylation in neural and hormonal control of cellular activity , 1982, Nature.