The SIRT1 deacetylase inhibits fat synthesis and stimulates fat oxidation in response to
fasting, but the underlying mechanisms remain unclear. Here we report that SREBP-1c, a
key lipogenic activator, is an in vivo target of SIRT1. SIRT1 interaction with SREBP-1c was
increased during fasting and decreased upon feeding, and consistently, SREBP-1c
acetylation levels were decreased during fasting in mouse liver. Acetylated SREBP-1c levels
were also increased in HepG2 cells treated with insulin and glucose to mimic feeding …