Defective molecular timer in the absence of XXXX leads to inefficient caspase activation.

@entity3437 @entity2036 @entity4674 @entity377 @entity17699 @entity8187 @entity855
In the intrinsic death pathway, @entity4674 (CC) released from mitochondria to the cytosol triggers @entity3437 apoptosome formation and subsequent caspase activation. This process can be recapitulated using recombinant @entity3437 and CC in the presence of @entity2036 @entity855 or @entity17699 [(d) @entity855 ] or using fresh cytosol and CC without the need of exogenous @entity2036 . Surprisingly, we found that stored cytosols failed to support CC-initiated caspase activation. Storage of cytosols at different temperatures led to the loss of all (deoxy) @entity2036 including (d) @entity855 . Addition of @entity17699 to such stored cytosols partially restored CC-initiated caspase activation. Nevertheless, CC could not induce complete @entity8187 /3 activation in stored cytosols, even with the addition of @entity17699 , despite robust @entity3437 oligomerization. The @entity3437 apoptosome, which functions as a proteolytic-based molecular timer appeared to be defective as auto-processing of recruited procaspase-9 was inhibited. Far Western analysis revealed that procaspase-9 directly interacted with @entity3437 and this interaction was reduced in the presence of physiological levels of @entity855 . Co-incubation of recombinant @entity3437 and procaspase-9 prior to CC and @entity855 addition inhibited CC-induced caspase activity. These findings suggest that in the absence of @entity377 such as @entity855 , direct association of procaspase-9 with @entity3437 leads to defective molecular timer, and thus, inhibits apoptosome-mediated caspase activation. Altogether, our results provide novel insight on @entity377 regulation of apoptosome.
