The major apoptotic pathway activated and suppressed by XXXX .

@entity522 @entity588 @entity9925 @entity4674 @entity8187 @entity2097 @entity281 @entity5353 @entity5828 @entity2383
Cells respond to @entity9925 infection by switching on the apoptotic program, implementation of which is usually suppressed by viral antiapoptotic functions. We show here that @entity9925 infection of HeLa cells or derivatives of MCF-7 cells was accompanied by the efflux of @entity4674 from mitochondria. This efflux occurred during both @entity281 (e.g., interrupted by @entity2097 - @entity5828 and ending with apoptosis) and productive infection (leading to cytopathic effect). The former type of infection, but not the latter, was accompanied by truncation of the proapoptotic protein @entity5353 . The virus-triggered @entity4674 efflux was suppressed by overexpression of @entity588 . Both @entity281 also resulted in a decreased level of procaspase-9, as revealed by Western blotting. In the former case, this decrease was accompanied by the accumulation of a protein with the electrophoretic mobility of active @entity8187 . In contrast, in the productively infected cells, the latter protein was absent but @entity8187 -related polypeptides with altered mobility could be detected. Both @entity8187 and @entity522 were shown to be essential for the development of such hallmarks of virus-induced apoptosis as chromatin condensation, DNA degradation, and nuclear fragmentation. These and some other results suggest the following scenario. @entity9925 infection activates the apoptotic pathway, involving @entity2383 , @entity4674 efflux, and consecutive activation of @entity8187 and @entity522 . The apoptotic signal appears to be amplified by a loop which includes secondary processing of @entity5353 . The implementation of the apoptotic program in productively infected cells may be suppressed, however, by the viral antiapoptotic functions, which act at a step(s) downstream of the @entity4674 efflux. The suppression appears to be caused, at least in part, by aberrant processing and degradation of procaspase-9.
