Regulation of a truncated isoform of AMP-activated protein kinase α (AMPKα) in response to hypoxia in the muscle of Pacific oyster Crassostrea gigas.

• Published in: Journal of Comparative Physiology B
• Main Authors: Guévélou, Eric, Huvet, Arnaud, Sussarellu, Rossana, Milan, Massimo, Guo, Ximing, Li, Li, Zhang, Guofan, Quillien, Virgile, Daniel, Jean-Yves, Quéré, Claudie, Boudry, Pierre, Corporeau, Charlotte
• Other Authors: Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Comparative Biomedicine and Food Science, Universita degli Studi di Padova, Haskin Shellfish Research Laboratory (HSRL), Rutgers, The State University of New Jersey New Brunswick (RU), Rutgers University System (Rutgers)-Rutgers University System (Rutgers), CAS Institute of Oceanology (IOCAS), Chinese Academy of Sciences Beijing (CAS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2013
• Subjects: envir; socio; Pacific; Crassostrea gigas; Pacific oyster
• Online Access: https://doi.org/10.1007/s00360-013-0743-6; https://hal.univ-brest.fr/hal-00787270

International audience 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.