Unformatted text preview: by a family of proteins called the IAP, for
inhibitor of apoptosis, family. Members of the IAP family directly interact
with caspases and suppress apoptosis by either inhibiting caspase activity
or by targeting caspases for ubiquitination and degradation in the proteasome. IAPs are present in both Drosophila and mammals (but not C. elegans),
and regulation of their activity or expression provides another mechanism
for controlling apoptosis. Regulation of IAPs is particularly important in
Drosophila, where initiator caspases are chronically activated but held in
check by IAPs ( Figure 17.9 ). Many signals that induce apoptosis in
Drosophila function by activating proteins that inhibit the IAPs, thus leading
to caspase activation. In mammalian cells, the permeabilization of mitoThis material cannot be copied, reproduced, manufactured, or disseminated in any
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CELL DEATH AND CELL RENEWAL FIGURE 17.8 The mitochondrial pathway...
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