Role of intracellular proteases in differentiation of L6 myoblast cells.
The activities of cathepsins B, L, and H increased by 3.0, 2.3, and 1.9 fold in differentiation of L6 myoblasts. Separating from the intrinsic inhibitor, both mu- and m-calpain activities also increased by 4.9 and 1.7 fold during differentiation. Calpeptin (10(-5)M), cell penetrating calpain inhibitor, blocked fusion of myoblast by 55% and increment of creatine phosphokinase (CPK) activity by 20.3% with inhibiting the activities of cathepsin L and mu-calpain. E-64(10(-4)M) did not block fusion of myoblasts but increment of CPK activity by 25.0% with inhibiting the activities of cathepsin L and B. Calpain may be involved in the process of myoblast fusion.
Department of Surgery II, Osaka University Medical School, Japan.
C
C
Ebisui
T
T
Tsujinaka
Y
Y
Kido
S
S
Iijima
M
M
Yano
H
H
Shibata
T
T
Tanaka
T
T
Mori
D000818:Animals; D002154:Calpain / Q000378:metabolism*; D002403:Cathepsins / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects; D002459:Cell Fusion; D002460:Cell Line; D010450:Endopeptidases / Q000378:metabolism*; D007700:Kinetics; D009132:Muscles / Q000166:cytology* / Q000201:enzymology / Q000502:physiology; D011480:Protease Inhibitors / Q000494:pharmacology*; D051381:Rats; D013379:Substrate Specificity; D013997:Time Factors
D011480:Protease Inhibitors; D002403:Cathepsins; D010450:Endopeptidases; D002154:Calpain