SIRT5 deacetylates and activates urate oxidase in liver mitochondria of mice

► Urate oxidase is identified as a substrate of SIRT5 protein. ► Urate oxidase is located both in mitochondria and peroxisomes. ► Urate oxidase is deacetylated and activated in liver mitochondria of SIRT5 Tg mice. ► In vitro-synthesized urate oxidase is acetylated when incubated with mitochondria.