Regulation of a truncated isoform of AMP-activated protein kinase alpha (AMPKalpha) in response to hypoxia in the muscle of Pacific oyster Crassostrea gigas
|Author(s)||Guevelou Eric1, Huvet Arnaud1, Sussarellu Rossana1, 2, Milan Massimo3, Guo Ximing4, Li Li5, Zhang Guofan5, Quillien Virgile1, Daniel Jean-Yves1, Quere Claudie1, Boudry Pierre1, Corporeau Charlotte1|
|Affiliation(s)||1 : IFREMER, Ctr Bretagne ZI Pointe Diable, LEMAR, UMR 6539, F-29280 Plouzane, France.
2 : CNRS, IUEM UBO, UMR 6539, LEMAR, F-29280 Plouzane, France.
3 : Univ Padua, Dept Comparat Biomed & Food Sci, Legnaro, Italy.
4 : Rutgers State Univ, Inst Marine & Coastal Sci, Haskin Shellfish Res Lab, Port Norris, NJ 08349 USA.
5 : Chinese Acad Sci, Inst Oceanol, Qingdao 266071, Peoples R China.
|Source||Journal Of Comparative Physiology B-biochemical Systemic And Environmental Physiology (0174-1578) (Springer Heidelberg), 2013-07 , Vol. 183 , N. 5 , P. 597-611|
|WOS© Times Cited||27|
|Keyword(s)||Marine bivalve, Crassostrea gigas, Hypoxia, AMP-activated protein kinase, Alternative splicing, Adductor muscle|
|Abstract||AMP-activated protein kinase α (AMPKα) is a key regulator of energy balance in many model species during hypoxia. In a marine bivalve, the Pacific oyster Crassostrea gigas, we analyzed the protein content of adductor muscle in response to hypoxia during 6 h. In both smooth and striated muscles, the amount of full-length AMP-activated protein kinase α (AMPKα) remained unchanged during hypoxia. However, hypoxia induced a rapid and muscle-specific response concerning truncated isoforms of AMPKα. In the smooth muscle, a truncated isoform of AMPKα was increased from 1 to 6 h of hypoxia, and was linked with accumulation of AKT kinase, a key enzyme of the insulin signaling pathway which controls intracellular glucose metabolism. In this muscle, aerobic metabolism was maintained over the 6 h of hypoxia, as mitochondrial citrate synthase activity remained constant. In contrast, in striated muscle, hypoxia did not induce any significant modification of neither truncated AMPKα nor AKT protein content, and citrate synthase activity was altered after 6 h of hypoxia. Together, our results demonstrate that hypoxia response is specific to muscle type in Pacific oyster, and that truncated AMPKα and AKT proteins might be involved in maintaining aerobic metabolism in smooth muscle. Such regulation might occur in vivo during tidal intervals that cause up to 6 h of hypoxia.|