Caspase7

               Pro-caspase9     Caspase9

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Caspase7

 

 

 

 

Caspase7

 

 
                                         

 

文字方塊: Apoptosis文字方塊: Cad 

 

 

Caspases play a key role during apoptotic execution. In an attempt to elucidate the specific role of caspase-7 we generated a chicken DT40 cell line in which both alleles of the gene were disrupted. Viability assays showed that caspase-7 -/- clones are more resistant to the common apoptosis-inducing drugs etoposide and staurosporine. Caspase-7 -/- cells show a delay in phosphatidylserine externalization and DNA fragmentation as well as cleavage of the caspase substrates PARP and lamins B1 and B2. Caspase affinity labeling and activity assays indicated that deficient cells exhibit a delay in caspase activation when compared to wild type DT40 cells, providing an explanation for the differences in apoptotic execution between caspase-7 null and wild type DT40 cells. These results strongly suggest that caspase-7 is involved earlier than other effector caspases in the apoptotic execution process in DT40 B lymphocytes.l