Up-regulation of a thioredoxin peroxidase-like protein, proliferation-associated gene, in hibernating bats.
Two-dimensional gel electrophoresis was used to assess differential protein expression between euthermic and hibernating states in heart of Myotis lucifugus. A hibernation-induced protein was identified by mass spectrometry as a thioredoxin peroxidase-like protein known as PAG. Western blotting confirmed up-regulation (>2-fold) and RT-PCR also revealed up-regulation (>5-fold) of pag mRNA. Cloning revealed a highly conserved sequence suggesting a conserved function for PAG. Oxidative stress markers, p-IkappaB-alpha (Ser 32) and p-HSP27 (Ser 78/82), were also up-regulated in heart and skeletal muscle during hibernation. Although there are selected increases in gene/protein expression during hibernation, general translation inhibition occurs as part of metabolic rate depression. This was confirmed by elevated levels of the inactive forms of the eIF2alpha (Ser 51) in both heart and skeletal muscle (2- to 5-fold higher than in euthermia) and the eEF2 (Thr 51) in skeletal muscle (a 15-fold increase). This study suggests that hibernators may use up-regulation of specific proteins to counteract oxidative stress.
Eddy
Sean F
SF
Departments of Chemistry and Biology, Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6. eddy@biochem.bumc.bu.edu
McNally
J D
JD
Storey
K B
KB
D000222:Adaptation, Physiological; D000595:Amino Acid Sequence; D000818:Animals; D002685:Chiroptera / Q000502:physiology*; D006321:Heart / Q000502:physiology*; D006360:Heat-Shock Proteins / Q000378:metabolism*; D006605:Hibernation / Q000502:physiology*; D020672:I-kappa B Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000502:physiology*; D009206:Myocardium / Q000378:metabolism; D000072000:NF-KappaB Inhibitor alpha; D018384:Oxidative Stress / Q000502:physiology; D010544:Peroxidases / Q000378:metabolism*; D054464:Peroxiredoxins; D017386:Sequence Homology, Amino Acid; D015854:Up-Regulation / Q000502:physiology
D006360:Heat-Shock Proteins; D020672:I-kappa B Proteins; D000072000:NF-KappaB Inhibitor alpha; D010544:Peroxidases; D054464:Peroxiredoxins