BSTA promotes mTORC2-mediated phosphorylation of Akt1 to suppress expression of FoxC2 and stimulate adipocyte differentiation.

Journal Article

Phosphorylation and activation of Akt1 is a crucial signaling event that promotes adipogenesis. However, neither the complex multistep process that leads to activation of Akt1 through phosphorylation at Thr³⁰⁸ and Ser⁴⁷³ nor the mechanism by which Akt1 stimulates adipogenesis is fully understood. We found that the BSD domain-containing signal transducer and Akt interactor (BSTA) promoted phosphorylation of Akt1 at Ser⁴⁷³ in various human and murine cells, and we uncovered a function for the BSD domain in BSTA-Akt1 complex formation. The mammalian target of rapamycin complex 2 (mTORC2) facilitated the phosphorylation of BSTA and its association with Akt1, and the BSTA-Akt1 interaction promoted the association of mTORC2 with Akt1 and phosphorylation of Akt1 at Ser⁴⁷³ in response to growth factor stimulation. Furthermore, analyses of bsta gene-trap murine embryonic stem cells revealed an essential function for BSTA and phosphorylation of Akt1 at Ser⁴⁷³ in promoting adipocyte differentiation, which required suppression of the expression of the gene encoding the transcription factor FoxC2. These findings indicate that BSTA is a molecular switch that promotes phosphorylation of Akt1 at Ser⁴⁷³ and reveal an mTORC2-BSTA-Akt1-FoxC2-mediated signaling mechanism that is critical for adipocyte differentiation.

Full Text

Duke Authors

Cited Authors

  • Yao, Y; Suraokar, M; Darnay, BG; Hollier, BG; Shaiken, TE; Asano, T; Chen, C-H; Chang, BH-J; Lu, Y; Mills, GB; Sarbassov, D; Mani, SA; Abbruzzese, JL; Reddy, SAG

Published Date

  • January 8, 2013

Published In

Volume / Issue

  • 6 / 257

Start / End Page

  • ra2 -

PubMed ID

  • 23300339

Electronic International Standard Serial Number (EISSN)

  • 1937-9145

International Standard Serial Number (ISSN)

  • 1945-0877

Digital Object Identifier (DOI)

  • 10.1126/scisignal.2003295

Language

  • eng