p53, Apaf-1, caspase-3, and -9 are dispensable for Cdk5 activation during cell death.
Cyclin-dependent kinase 5 (Cdk5) is a member of the cyclin-dependent kinase family that is mostly seen in neurons, does not vary with cell cycle, and is activated in many neurodegenerative disorders and other non-neuronal pathologies, but its relationship to non-neuronal apoptosis is not understood, nor is the control of the activation of Cdk5 by its activators. The most widely studied activator of Cdk5, p35, is cleaved to p25 by calpain, an event that has been linked with activation of Cdk5 and neuronal death. Here we report that calpain-mediated Cdk5/p25 activation accompanies non-neuronal as well as neuronal cell death, suggesting that the p35/calpain/p25/Cdk5 activation sequence is a general feature of cell death. We further demonstrate that Cdk5 can be activated in the absence of p53, Apaf-1, caspase-9, and -3 during cell death, indicating that its activation relates more to cell death than to a specific pathway of apoptosis.
Lin
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L
Department of Biology, Queens College and Graduate Center of the City University of New York, 65-30 Kissena Blvd, Flushing, NY 11367, USA.
Ye
Y
Y
Zakeri
Z
Z
D000818:Animals; D017209:Apoptosis / Q000235:genetics / Q000502:physiology*; D053477:Apoptotic Protease-Activating Factor 1; D001483:Base Sequence; D053148:Caspase 3; D053453:Caspase 9; D020169:Caspases / Q000235:genetics / Q000378:metabolism*; D002461:Cell Line, Transformed; D051360:Cyclin-Dependent Kinase 5 / Q000378:metabolism*; D004247:DNA / Q000235:genetics; D004789:Enzyme Activation; D005260:Female; D016158:Genes, p53; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011247:Pregnancy; D011506:Proteins / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*
C506593:Apaf1 protein, mouse; D053477:Apoptotic Protease-Activating Factor 1; D047908:Intracellular Signaling Peptides and Proteins; D011506:Proteins; D016159:Tumor Suppressor Protein p53; D004247:DNA; D051360:Cyclin-Dependent Kinase 5; C495906:Cdk5 protein, mouse; C505409:Casp3 protein, mouse; C506434:Casp9 protein, mouse; D053148:Caspase 3; D053453:Caspase 9; D020169:Caspases