Diurnal regulation of Acyl-CoA synthetase 3 (ACSF3) underlies daily mitochondrial lysine-malonylation and hepatic metabolism

Circadian rhythms are fundamental to maintaining health and are implicated in various diseases. In the liver, daily rhythms are coordinated via the interplay between feeding rhythms and the molecular circadian clock, ensuring metabolic homeostasis. Disruption of feeding rhythms can lead to circadian misalignment, contributing to metabolic disorders, yet the underlying molecular mechanisms remain unclear. Recent evidence suggests that post-translational modifications play a key role in regulating circadian functional output. In this framework, mitochondria serve as a convergence point, integrating rhythms in metabolism, feeding rhythms and the circadian clock. In the present study, we used a multi-omics approach to investigate the role of the Acyl-CoA synthetase 3 (ACSF3) in driving lysine-malonylation and in regulating daily hepatic metabolism. We found that ACSF3 expression and its mediated impact on lysine-malonylation are rhythmic and largely governed by feeding rhythms. While hepatic ACSF3 knockdown did not alter diet-induced metabolic abnormalities, our results demonstrate that ACSF3 plays a role in the diurnal regulation of liver glycogen storage, de novo lipogenesis, and triglyceride synthesis.