An understanding of the protein adaptations that support mammalian hibernation is coming from several different approaches. New studies in my lab are (a) using cDNA library screening to identify genes that are up-regulated in hibernation, (b) analyzing the role of reversible protein phosphorylation in the control of membrane ion pumps in torpor, (c) assessing temperature-dependent properties of protein kinases that alter their function in euthermic vs hibernating states, and (d) characterizing fatty acid binding proteins of hibernating vs nonhibernating species to identify properties that support intracellular fatty acid transport at low body temperatures