The calcineurin activity and MCIP1.4 mRNA levels are increased by innervation in regenerating soleus muscle.
The level of active subunit of calcineurin and the calcineurin (Cn) enzyme activity are increased in innervated but not in denervated slow type regenerating skeletal soleus muscle. These nerve-dependent increases were not accompanied by similar increases in the mRNA levels. The changes in the mRNA level of the modulatory calcineurin interacting protein, MCIP1.4, reflected the calcineurin activity and did not increase in denervated regenerating muscles compared to the innervated regenerating controls. The increases in Cn activity and in MCIP1.4 mRNA levels occurred before the switch from fast to slow-type myosin heavy chain isoforms, a phenomenon similarly known to be dependent on innervation. This highlights the role of mediators, acting between the nerve and calcineurin, in the formation of slow fiber identity.
Fenyvesi
Rita
R
Institute of Biochemistry, Faculty of Medicine, University of Szeged, P.O. Box 427, H-6701 Szeged, Hungary.
Rácz
Gábor
G
Wuytack
Frank
F
Zádor
Erno
E
D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D019703:Calcineurin / Q000235:genetics / Q000378:metabolism*; D017931:DNA Primers; D008297:Male; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000294:innervation / Q000378:metabolism* / Q000502:physiology; D009218:Myosins / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012038:Regeneration; D020133:Reverse Transcriptase Polymerase Chain Reaction
D017931:DNA Primers; D009124:Muscle Proteins; D012333:RNA, Messenger; D019703:Calcineurin; D009218:Myosins