TY - JOUR
T1 - Cell-cycle-regulated activation of Akt kinase by phosphorylation at its carboxyl terminus
AU - Liu, Pengda
AU - Begley, Michael
AU - Michowski, Wojciech
AU - Inuzuka, Hiroyuki
AU - Ginzberg, Miriam
AU - Gao, Daming
AU - Tsou, Peiling
AU - Gan, Wenjian
AU - Papa, Antonella
AU - Kim, Byeong Mo
AU - Wan, Lixin
AU - Singh, Amrik
AU - Zhai, Bo
AU - Yuan, Min
AU - Wang, Zhiwei
AU - Gygi, Steven P.
AU - Lee, Tae Ho
AU - Lu, Kun Ping
AU - Toker, Alex
AU - Pandolfi, Pier Paolo
AU - Asara, John M.
AU - Kirschner, Marc W.
AU - Sicinski, Piotr
AU - Cantley, Lewis
AU - Wei, Wenyi
N1 - Funding Information:
Acknowledgements We thank J. Guo, J.J. Liu, A.W. Lau, S. Shaik, A. Tron, X. Dai and K. Xu for reading the manuscript, S.B. Breitkopf for help with mass spectrometry experiments, Y. Geng, L. Liu, K. Ran, R. Chin and S. Elloul for providing reagents, and members of the Wei, Toker, Sicinski, Pandolfi and Cantley laboratories for discussions. W.W. is an American Cancer Society and a Leukemia & Lymphoma Society research scholar. P.L. is supported by 5T32HL007893. This work was supported in part by National Institutes of Health grants to W.W. (GM089763, GM094777 and CA177910), J.M.A. (2P01CA120964) and P.S. (R01CA132740).
PY - 2014
Y1 - 2014
N2 - Akt, also known as protein kinase B, plays key roles in cell proliferation, survival and metabolism. Akt hyperactivation contributes to many pathophysiological conditions, including human cancers, and is closely associated with poor prognosis and chemo-or radiotherapeutic resistance. Phosphorylation of Akt at S473 (ref. 5) and T308 (ref. 6) activates Akt. However, it remains unclear whether further mechanisms account for full Akt activation, and whether Akt hyperactivation is linked to misregulated cell cycle progression, another cancer hallmark. Here we report that Akt activity fluctuates across the cell cycle, mirroring cyclin A expression. Mechanistically, phosphorylation of S477 and T479 at the Akt extreme carboxy terminus by cyclin-dependent kinase 2 (Cdk2)/cyclin A or mTORC2, under distinct physiological conditions, promotes Akt activation through facilitating, or functionally compensating for, S473 phosphorylation. Furthermore, deletion of the cyclin A2 allele in the mouse olfactory bulb leads to reduced S477/T479 phosphorylation and elevated cellular apoptosis. Notably, cyclin A2-deletion-induced cellular apoptosis in mouse embryonic stem cells is partly rescued by S477D/T479E-Akt1, supporting a physiological role for cyclin A2 in governing Akt activation. Together, the results of our study show Akt S477/T479 phosphorylation to be an essential layer of the Akt activation mechanism to regulate its physiological functions, thereby providing a new mechanistic link between aberrant cell cycle progression and Akt hyperactivation in cancer.
AB - Akt, also known as protein kinase B, plays key roles in cell proliferation, survival and metabolism. Akt hyperactivation contributes to many pathophysiological conditions, including human cancers, and is closely associated with poor prognosis and chemo-or radiotherapeutic resistance. Phosphorylation of Akt at S473 (ref. 5) and T308 (ref. 6) activates Akt. However, it remains unclear whether further mechanisms account for full Akt activation, and whether Akt hyperactivation is linked to misregulated cell cycle progression, another cancer hallmark. Here we report that Akt activity fluctuates across the cell cycle, mirroring cyclin A expression. Mechanistically, phosphorylation of S477 and T479 at the Akt extreme carboxy terminus by cyclin-dependent kinase 2 (Cdk2)/cyclin A or mTORC2, under distinct physiological conditions, promotes Akt activation through facilitating, or functionally compensating for, S473 phosphorylation. Furthermore, deletion of the cyclin A2 allele in the mouse olfactory bulb leads to reduced S477/T479 phosphorylation and elevated cellular apoptosis. Notably, cyclin A2-deletion-induced cellular apoptosis in mouse embryonic stem cells is partly rescued by S477D/T479E-Akt1, supporting a physiological role for cyclin A2 in governing Akt activation. Together, the results of our study show Akt S477/T479 phosphorylation to be an essential layer of the Akt activation mechanism to regulate its physiological functions, thereby providing a new mechanistic link between aberrant cell cycle progression and Akt hyperactivation in cancer.
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U2 - 10.1038/nature13079
DO - 10.1038/nature13079
M3 - Article
C2 - 24670654
AN - SCOPUS:84899484738
VL - 508
SP - 541
EP - 545
JO - Nature
JF - Nature
SN - 0028-0836
IS - 7497
ER -