Reversible Protein Acetylation in the Regulation of Mammalian Hibernation

To survive the winter, many small mammals use hibernation. Employing a remarkable strategy of metabolic rate depression these animals accrue profound energy savings by remaining in a torpid state over most of the winter. Global metabolic suppression is mediated by intricate molecular mechanisms, including the post-translational modification of cellular proteins. One such modification, reversible protein acetylation, is an important regulator of metabolism, but little is known about its relevance to hibernation. This thesis provides an initial characterization of possible functions of reversible protein acetylation, and several enzymes that mediate the process (protein lysine acetyltransferases (KATs) and deacetylases (SIRTs)), in the context of a rodent model of mammalian hibernation, the thirteen-lined ground squirrel, Ictidomys tridecemlineatus. Notably, SIRT and KAT protein expression and activities increased in skeletal muscle and brown adipose tissue, respectively, during torpor, in correlation with fluctuations in downstream target acetylation. Such changes identify roles for protein acetylation during hibernation.