The double-stranded RNA-dependent protein kinase (PKR) induces apoptosis by activation of the FADD/caspase 8 pathway. Here we show that upon PKR expression, caspase 9 is processed and activated, correlating with the translocation of cytochrome c to the cytoplasm and breakdown of mitochondrial potential upon Bax insertion. However, treatment of cells with an inhibitor of caspase 9 could not prevent PKR-induced apoptosis. During PKR-induced apoptosis, caspase 9 is activated downstream of caspase 8. Our findings revealed that caspase 9, although dispensable, is a mediator of PKR-induced cell death. © 2002 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies.
Gil, J., García, M. A., & Esteban, M. (2002). Caspase 9 activation by the dsRNA-dependent protein kinase, PKR: Molecular mechanism and relevance. FEBS Letters, 529(2–3), 249–255. https://doi.org/10.1016/S0014-5793(02)03348-3