Phosphorylase kinase activity in I/strain neonatal skeletal muscle with a deficiency in alpha/alpha' subunit mRNAs.
In the adult I/LnJ mouse skeletal muscle, phosphorylase kinase activity is 0.2% of that in normal. This deficiency results from a paucity of mRNA's for the phosphorylase kinase regulatory subunit- alpha and its isoform alpha'. However, in the I/LnJ neonatal skeletal muscle phosphorylase kinase activity is 20-25% of that in normal. During the first two months of development this activity decreases while in normal tissue it increases. The developmental differences in the magnitude of the I/LnJ deficiency indicate the possibility of stage specific mechanisms regulating the accumulation of alpha/alpha' mRNAs. To investigate this possibility, the abundance of alpha/alpha' mRNAs and of the catalytic subunit, gamma, mRNAs were compared by Northern Blot analysis. The results demonstrate that neonatal and adult I/LnJ skeletal muscle have a similar paucity of alpha/alpha' mRNAs whereas accumulation of gamma mRNAs is not significantly different from normal.
Bender
P K
PK
Department of Biochemistry and Nutrition, Virginia Polytechnic Institute, Blacksburg 24061.
D000375:Aging; D000818:Animals; D000831:Animals, Newborn; D015152:Blotting, Northern; D046911:Macromolecular Substances; D051379:Mice; D008813:Mice, Inbred ICR; D008817:Mice, Mutant Strains; D024510:Muscle Development; D009132:Muscles / Q000201:enzymology*; D010764:Phosphorylase Kinase / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D011061:Poly A / Q000235:genetics / Q000302:isolation & purification; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism
D046911:Macromolecular Substances; D012333:RNA, Messenger; D011061:Poly A; D012313:RNA; D010764:Phosphorylase Kinase