Cytochrome c promoter activity in soleus and white vastus lateralis muscles in rats.
Cytochrome c protein and mRNA are 300 and 100% higher, respectively, in the soleus muscle (predominantly slow-twitch oxidative) than the white vastus lateralis (predominately fast-twitch glycolytic) muscle (W. W. Winder, K. M. Baldwin, and J. O. Holloszy. Eur. J. Biochem. 47: 461-467, 1974; M. M. Lai and F. W. Booth. J. Appl. Physiol. 69: 843-848, 1990). However, the mechanisms controlling these differences in cytochrome c mRNA are largely unknown. The present study employed direct plasmid injection techniques to determine whether the proximal promoter (-726 to +610) of the rat somatic cytochrome c gene was more active in the soleus than in white vastus lateralis muscles in rats. No difference between the soleus and white vastus lateralis muscles for the activities of the -726, -631, -489, -326, -215, -159 and -149 cytochrome c promoters was noted. The results of this study suggest that additional elements (outside of -726 to +610) in the cytochrome c gene may be required, or posttranscriptional regulation may account, for the higher cytochrome c mRNA in the slow-twitch oxidative muscle.
Yan
Z
Z
Department of Integrative Biology, Pharmacology, and Physiology, University of Texas Medical School, Houston, Texas, 77030, USA.
Booth
F W
FW
D000818:Animals; D003574:Cytochrome c Group / Q000235:genetics / Q000502:physiology*; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics / Q000502:physiology; D008156:Luciferases; D018656:Muscle Fibers, Fast-Twitch / Q000201:enzymology / Q000502:physiology; D018657:Muscle Fibers, Slow-Twitch / Q000201:enzymology / Q000502:physiology; D018482:Muscle, Skeletal / Q000201:enzymology / Q000502:physiology*; D010957:Plasmids / Q000235:genetics / Q000502:physiology; D011401:Promoter Regions, Genetic / Q000502:physiology*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley
D003574:Cytochrome c Group; D012333:RNA, Messenger; D008156:Luciferases