Involvement of mu- and m-calpains and protein kinase C isoforms in L8 myoblast differentiation.
Int J Biochem Cell Biol
; 38(4): 662-70, 2006.
Article
em En
| MEDLINE
| ID: mdl-16387524
ABSTRACT
The objectives were to investigate the roles of different calpains and protein kinase C (PKC) isoforms in muscle differentiation. Concentrations of mu- and m-calpain increased significantly whereas PKCalpha and delta declined significantly during L8 myoblast differentiation. Both mu-calpain and m-calpain antisense oligonucleotides inhibited myotube formation and creatine kinase activity during L8 myoblast differentiation. These results implied that both mu- and m-calpain were involved in L8 myoblast differentiation. To investigate the involvement of calpain in regulation of PKC concentrations, mu-calpain antisense oligonucleotides were added to L8 myoblasts. PKCalpha remained unchanged and PKCdelta declined. By adding m-calpain antisense oligonucleotides instead, PKCalpha level remained unchanged and PKCdelta concentrations increased significantly during differentiation. These results suggest that PKCalpha, but not PKCdelta, is the substrate for mu-calpain and PKCalpha and delta are the substrates for the m-calpain. In addition, more phosphorylated myogenin was found in day 2 antisense oligonucleotides treated L8 cells. It is concluded that the decline of PKCalpha mediated by m- and mu-calpain is essential for L8 myoblast differentiation. The decline of PKC during myoblast differentiation may cause hypo-phosphorylation of myogenin, which in turn activates muscle-specific genes during myogenesis.
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Base de dados:
MEDLINE
Assunto principal:
Calpaína
/
Diferenciação Celular
/
Mioblastos
/
Proteína Quinase C-alfa
/
Proteína Quinase C-delta
Limite:
Animals
Idioma:
En
Ano de publicação:
2006
Tipo de documento:
Article