Up-regulation of fatty acid-binding proteins during hibernation in the little brown bat, Myotis lucifugus.
Hibernating animals rely primarily on lipids throughout winter as their primary fuel source, thus it is hypothesized that an increase in genes and proteins relating to lipid transport will increase accordingly. The cloning and expression of heart type fatty acid-binding protein (h-fabp) from a mammalian hibernator, the little brown bat Myotis lucifugus, is presented. Northern blot analysis revealed that transcript levels of h-fabp were significantly higher during hibernation in brown adipose tissue and skeletal muscle compared with levels in euthermic bats. Similarly, heterologous probing with rat adipose type a-fabp found 3.9-fold higher levels of a-fabp transcripts in brown adipose from hibernating animals. Levels of A- and H-FABP protein were quantified in tissues of euthermic versus hibernating animals by Western blotting. A-FABP was 4-fold higher in brown adipose of hibernating, compared with euthermic bats, whereas H-FABP was significantly higher in hibernator brown adipose, heart and skeletal muscle. The present work implicates FABPs as important elements related to the hibernating state in mammals; alterations in gene and protein expression along with amino acid substitutions are shown. These likely contribute to optimizing the function of FABPs at the low body temperatures (near 0 degrees C) experienced in the hibernating state.
Eddy
Sean F
SF
Department of Chemistry and Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada K1S 5B6. eddy@biochem.bumc.bu.edu
Storey
Kenneth B
KB
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001831:Body Temperature; D002352:Carrier Proteins / Q000235:genetics* / Q000502:physiology; D002685:Chiroptera / Q000502:physiology*; D017931:DNA Primers; D018076:DNA, Complementary / Q000235:genetics; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D006321:Heart / Q000502:physiology; D006605:Hibernation / Q000502:physiology*; D015336:Molecular Probe Techniques; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D015854:Up-Regulation / Q000502:physiology*
D002352:Carrier Proteins; D017931:DNA Primers; D018076:DNA, Complementary; C490174:Fabp7 protein, rat; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins