title: Activation of AMP-dependent protein kinase by hypoxia and hypothermia in the liver of frog Rana perezi.
abstract: We have investigated different signaling molecules that could be activated by temperature acclimation and hypoxia, using an experimental approach consisting in submerging frogs in a water-filled box maintained at 2-4 degrees C at ambient oxygen levels or supplied with 98% N2:2% CO2 for normoxia or hypoxia conditions, respectively. The results obtained showed no significant changes in the expression of heat shock protein 70. The phosphorylation state of AMP-dependent activated protein kinase, the down-stream component of a protein kinase cascade that acts as an intracellular energy sensor, was significantly increased in both experimental conditions, showing higher values in the absence of oxygen. Similarly, the phosphorylation state of one of its known substrates, elongation factor 2, was also increased, consistent with the arrest of protein synthesis. These results point out an important role of this kinase, adjusting the rates of ATP-consuming and ATP-generating pathways, in the survival strategies to hypoxia and hypothermia.
authors.affiliation: Unitat de Bioquímica i Biologia Molecular, Departament de Ciències Fisiològiques II, Campus de Bellvitge, Universitat de Barcelona, Feixa Llarga s/n, E-08907 L'Hospitalet, Spain.
authors.forename: Mireia
authors.initials: M
authors.lastname: Bartrons
authors.forename: Enric
authors.initials: E
authors.lastname: Ortega
authors.forename: Mercè
authors.initials: M
authors.lastname: Obach
authors.forename: María Nieves
authors.initials: MN
authors.lastname: Calvo
authors.forename: Aurea
authors.initials: A
authors.lastname: Navarro-Sabaté
authors.forename: Ramon
authors.initials: R
authors.lastname: Bartrons
mesh_terms: D000064:Acclimatization; D000818:Animals; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D004789:Enzyme Activation; D007035:Hypothermia / Q000201:enzymology*; D000860:Hypoxia / Q000201:enzymology*; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008297:Male; D011898:Ranidae / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D017868:Cyclic AMP-Dependent Protein Kinases