title: Differential gene expression of muscle-specific ubiquitin ligase MAFbx/Atrogin-1 and MuRF1 in response to immobilization-induced atrophy of slow-twitch and fast-twitch muscles.
abstract: We examined muscle-specific ubiquitin ligases MAFbx/Atrogin-1 and MuRF1 gene expression resulting from immobilization-induced skeletal muscle atrophy of slow-twitch soleus and fast-twitch plantaris muscles. Male C57BL/6 mice were subjected to hindlimb immobilization, which induced similar percentage decreases in muscle mass in the soleus and plantaris muscles. Expression of MAFbx/Atrogin-1 and MuRF1 was significantly greater in the plantaris muscle than in the soleus muscle during the early stage of atrophy. After a 3-day period of atrophy, total FOXO3a protein level had increased in both muscles, while phosphorylated FOXO3a protein had decreased in the plantaris muscle, but not in the soleus muscle. PGC-1α protein expression did not change following immobilization in both muscles, but basal PGC-1α protein in the soleus was markedly higher than that in plantaris muscles. These data suggest that although soleus and plantaris muscles atrophied to a similar extent and that muscle-specific ubiquitin protein ligases (E3) may contribute more to the atrophy of fast-twitch muscle than to that of slow-twitch muscle during immobilization.
authors: School of Physical Education, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa, 259-1292, Japan.
authors: Takeshi
authors: T
authors: Okamoto
authors: Suguru
authors: S
authors: Torii
authors: Shuichi
authors: S
authors: Machida
mesh_terms: D000818:Animals; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors / Q000235:genetics; D019417:Hindlimb Suspension / Q000379:methods; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018656:Muscle Fibers, Fast-Twitch / Q000378:metabolism / Q000502:physiology*; D018657:Muscle Fibers, Slow-Twitch / Q000378:metabolism / Q000502:physiology*; D009124:Muscle Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism; D009133:Muscular Atrophy / Q000235:genetics* / Q000378:metabolism; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D010766:Phosphorylation; D044843:SKP Cullin F-Box Protein Ligases / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics; D014157:Transcription Factors; D000070584:Tripartite Motif Proteins; D044767:Ubiquitin-Protein Ligases / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism
chemical_list: D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors; C474033:FoxO3 protein, mouse; D009124:Muscle Proteins; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; C485290:Ppargc1a protein, mouse; D015534:Trans-Activators; D014157:Transcription Factors; D000070584:Tripartite Motif Proteins; C486691:Fbxo32 protein, mouse; D044843:SKP Cullin F-Box Protein Ligases; C499084:Trim63 protein, mouse; D044767:Ubiquitin-Protein Ligases