Regulation of adipogenesis by cytoskeleton remodelling is facilitated by acetyltransferase MEC-17-dependent acetylation of α-tubulin

Cytoskeleton remodelling is a prerequisite step for the morphological transition from preadipocytes to mature adipocytes. Although microtubules play a pivotal role in organizing cellular structure, regulation of microtubule dynamics during adipogenesis remains unclear. In the present paper we show that acetylation of alpha-tubulin is up-regulated during adipogenesis, and adipocyte development is dependent on alpha-tubulin acetylation, as expression of an acetylation-resistant alpha-tubulin mutant significantly inhibits adipogenesis. Moreover, acetylation of a-tubulin is under the control of the acetyltransferase MEC-17 and deacetylases SIRT2 (Sirtuin 2) and HDAC6 (histone deacetylase 6). Adipocyte development is inhibited in MEC-17-knockdown cells, but enhanced in MEC-17-overexpressing cells. Finally, we show that katanin, a microtubule-severing protein with enhanced activity on acetylated-tubulin, is actively involved in adipogenesis. We propose that co-ordinated up-regulation of alpha-tubulin acetylation initiates cytoskeleton remodelling by promoting alpha-tubulin severing by katanin which, in turn, allows expansion of lipid droplets and accelerates the morphological transition toward mature adipocytes.