Presence of active AKT in the nucleus upon adipocyte differentiation of 3T3-L1 cells

TL;DR

The study shows that active AKT is present in the nucleus during fat cell development, suggesting it plays a key role in this process.

Contribution

The study demonstrates for the first time that endogenous active AKT is present in the nucleus during adipogenesis.

Findings

Active AKT phosphorylated at Ser-473 increases rapidly after differentiation induction in 3T3-L1 cells.

Elevated active AKT levels are maintained in both cytoplasm and nucleus during adipogenesis.

Nuclear AKT is suggested to play an important role in adipocyte differentiation.

Abstract

AKT is an essential player in the phosphoinositide 3-kinase (PI3K) signalling pathway. Although the mechanisms of its action are well understood at the plasma membrane, AKT can also be found in the nucleus. In adipocytes, this pathway is activated during the process of adipogenesis and solicits both plasma membrane and nuclear AKT activity. However, the endogenous presence of active AKT in the nucleus during adipogenesis has not been shown. Here, we show that the levels of active AKT phosphorylated at Ser-473 increase rapidly after the induction of differentiation in 3T3-L1 cells, both in the cytoplasm and in the nucleus, and tend to remain elevated over the course of differentiation. In conclusion, these results support the notion that nuclear AKT plays an important role in this process.

Figures