title: AMP-activated protein kinase (AMPK) α2 subunit mediates glycolysis in postmortem skeletal muscle.
abstract: Postmortem glycolysis is directly linked to the incidences of PSE (pale, soft and exudative) and DFD (dark, firm and dry) meats which cause significant loss to meat industry. AMP-activated protein kinase (AMPK) is a major regulator of postmortem glycolysis. However, there are two isoforms of the AMPKα catalytic subunit, and their roles in glycolysis of postmortem muscle remain unclear. The objective was to identify the isoform specific roles of AMPK in postmortem glycolysis. Wild type, AMPKα1, and AMPKα2 knockout (KO) mice were used in the current study. AMPK in Longissimus muscle was activated shortly after death. AMPKα2 but not AMPKα1 KO abolished the activity of AMPK in postmortem muscle. In addition, AMPKα2 KO reduced postmortem pH decline and the generation of lactate, while AMPKα1 KO had no significant effect. Finally, the glycogen content of skeletal muscle was reduced in AMPKα2 KO but not AMPKα1 KO mice. Data clearly demonstrate that AMPKα2 catalytic subunit mainly regulates postmortem glycolysis in muscle.
authors.affiliation: College of Food Science, Inner Mongolia Agricultural University, Hohhot, China.
authors.forename: Junfang
authors.initials: J
authors.lastname: Liang
authors.forename: Qiyuan
authors.initials: Q
authors.lastname: Yang
authors.forename: Mei-Jun
authors.initials: MJ
authors.lastname: Zhu
authors.forename: Ye
authors.initials: Y
authors.lastname: Jin
authors.forename: Min
authors.initials: M
authors.lastname: Du
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000378:metabolism*; D000818:Animals; D006003:Glycogen / Q000378:metabolism*; D006019:Glycolysis; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000378:metabolism; D008460:Meat; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018482:Muscle, Skeletal / Q000378:metabolism*; D011180:Postmortem Changes; D020033:Protein Isoforms
chemical_list: D020033:Protein Isoforms; D019344:Lactic Acid; D006003:Glycogen; C548179:Prkaa1 protein, mouse; C534978:Prkaa2 protein, mouse; D055372:AMP-Activated Protein Kinases
keywords: AMPK; Glycolysis; Isoform; Meat; Postmortem; Skeletal muscle