Differential post-translational modification of mitochondrial enzymes corresponds with metabolic suppression during hibernation.

Differential post-translational modification of mitochondrial enzymes corresponds with metabolic suppression during hibernation. Am J Physiol Regul Integr Comp Physiol. 2019 May 08;: Authors: Mathers KE, Staples JF Abstract During hibernation, small mammals, including the 13-lined ground squirrel (Ictidomys tridecemlineatus), cycle between two distinct metabolic states: torpor, where metabolic rate is suppressed by >95% and body temperature falls to ~5 °C, and interbout euthermia (IBE), where both metabolic rate and body temperature rapidly increase to euthermic levels. Suppression of whole-animal metabolism during torpor is paralleled by rapid, reversible suppression of mitochondrial respiration. We hypothesized that these changes in mitochondrial metabolism are regulated by post-translational modifications to mitochondrial proteins. Differential 2D gel electrophoresis and 2D Blue-Native PAGE revealed differences in the isoelectric point of several liver mitochondrial proteins between torpor and IBE. Q-TOF LC/MS and MALDI mass spectrometry identified these as proteins involved in β-oxidation, Krebs cycle, ROS detoxification and the electron transport system (ETS). Immunoblots revealed that subunit 1 of ETS complex IV was acetylated during torpor but not IBE. Phosphoprotein staining revealed significantly greater phosphorylation of succinyl-coA ligase and the flavoprotein subunit of ETS complex II in IBE compared to torpor. In a...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - Category: Physiology Authors: Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research