| Calpain 3 dependent IkappaBalpha degradation was reconstituted in vitro , supporting a possible in vivo sequence of events leading from calpain 3 deficiency to IkappaBkappa accumulation , prevention of nuclear translocation of NF kappaB , and ultimately apoptosis . ^^^ Therefore calpain 3 , present in healthy muscle as sarcoplasmic and nuclear forms , may control IkappaBalpha turnover and indirectly regulate NF kappaB dependent expression of survival genes . ^^^ Apoptotic myonuclei were recently detected in muscular biopsy specimens of LGMD2A patients , and apoptosis was found to be correlated with altered subcellular distribution of inhibitory protein kappaBalpha ( IkappaBalpha ) and nuclear factor kappaB ( NF kappaB ) , resulting in sarcoplasmic sequestration of NF kappaB . ^^^ |