Correlations between MyoD, myogenin, SERCA1, SERCA2 and phospholamban transcripts during transformation of type-II to type-I skeletal muscle fibers.
Canine latissimus dorsi, composed predominantly of fast-twitch muscle fibers, were subjected to chronic 1 Hz neuromuscular stimulation for periods up to 42 days to induce changes in gene expression. This produced down regulation of SERCA1 (fast-twitch isoform of sarco(endo)plasmic reticulum Ca2+-ATPase), a gene product of fast-twitch muscle, and up regulation fo SERCA2 (slow-twitch isoform of sarco(endo)plasmic reticulum Ca2+-ATPase) and phospholamban, products of genes expressed by slow-twitch muscles. To assess the involvement of MyoD and myogenin in the regulation of the expression of these genes their levels were measured during the stimulation period. The prompt, at 7 days, fall in SERCA1 mRNA preceded the fall in MyoD by about 7 days, suggesting that the decline in MyoD was not causally related to the decline in SERCA1. The prompt rise in SERCA2 mRNA at 7 days preceded the rise in myogenin by 14 days. The rise in myogenin at 21 days did correlate with the similar rise in phospholamban mRNA.
Hu
P
P
Department of Physiology, Medical College of Virginia/Virginia Commonwealth University, Richmond, VA 23298, USA.
Zhang
K M
KM
Wright
L D
LD
Spratt
J A
JA
Briggs
F N
FN
D000818:Animals; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D004285:Dogs; D018656:Muscle Fibers, Fast-Twitch / Q000378:metabolism*; D018657:Muscle Fibers, Slow-Twitch / Q000378:metabolism*; D009124:Muscle Proteins / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000502:physiology*; D018008:Myogenin / Q000378:metabolism*; D000099211:Phospholamban
D002135:Calcium-Binding Proteins; D009124:Muscle Proteins; D018008:Myogenin; D000099211:Phospholamban