Proteomic analysis of mdx skeletal muscle: Great reduction of adenylate kinase 1 expression and enzymatic activity.
To investigate the pathophysiological events of Duchenne muscular dystrophy, we analyzed alterations of protein expression in hindlimb muscles of three month old mdx mice using two-dimensional gel electrophoresis and mass spectrometry. About 40 differentially expressed proteins from the cytosolic fraction and 20 from the microsomal fraction of mdx hindlimb muscles were identified. Among these altered proteins, adenylate kinase 1 (AK 1) was particular interesting because its decrease in abundance was so dramatic (> four-fold). Enzymatic assays demonstrated that AK 1 activity was also decreased in mdx mice. Furthermore, the expression and enzymatic activity of AK 1 were consistently reduced in mdx mice at one and six months of age, suggesting a direct relationship between the lack of dystrophin and alteration of AK 1. Along with AK 1, creatine kinase (CK) provides a major pathway for regulation of nucleotide ratios and energy metabolism in muscles. To gain a better understanding of mechanisms of energy metabolism, we also investigated CK activities in these mdx mice at different ages. Our results suggested that decreased AK 1 expression and activity might result in redistribution of energy flow through the alternative CK system, thus a compensatory potential might limit cellular energy failure in mdx skeletal muscle.
Ge
Yue
Y
Graduate Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, 48109, USA.
Molloy
Mark P
MP
Chamberlain
Jeffrey S
JS
Andrews
Philip C
PC
D000262:Adenylyl Cyclases / Q000032:analysis* / Q000378:metabolism; D000367:Age Factors; D000818:Animals; D015153:Blotting, Western; D003402:Creatine Kinase / Q000032:analysis / Q000378:metabolism; D003600:Cytosol / Q000737:chemistry / Q000378:metabolism; D030562:Databases, Protein; D016189:Dystrophin / Q000032:analysis; D049029:Dystrophin-Associated Proteins; D015180:Electrophoresis, Gel, Two-Dimensional; D051379:Mice; D008810:Mice, Inbred C57BL; D018101:Mice, Inbred mdx; D008861:Microsomes / Q000737:chemistry; D018482:Muscle, Skeletal / Q000737:chemistry / Q000201:enzymology* / Q000473:pathology; D009137:Muscular Dystrophy, Animal / Q000201:enzymology* / Q000378:metabolism; D009479:Neuropeptides / Q000032:analysis; D020543:Proteome / Q000032:analysis / Q000378:metabolism; D040901:Proteomics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D016189:Dystrophin; D049029:Dystrophin-Associated Proteins; D009479:Neuropeptides; D020543:Proteome; C098885:dystrobrevin; D003402:Creatine Kinase; D000262:Adenylyl Cyclases; C106670:adenylyl cyclase 1