Protein kinase C involvement in apoptosis.
1. Conflicting observations on the involvement of PKC in apoptosis point to a great variability depending on cell type, agent or condition causing apoptosis, phase of cell cycle and intracellular signaling pathway. 2. Inhibition by PKC of store-operated calcium entry mechanisms, which are sensitive to the oncoprotein bcl-2, should block the activation of calcium-dependent enzymes triggering the apoptotic cell death. 3. Activation of phosphatases by ceramide and inhibition of PKC by sphingosine seem to mediate the sphingomyelin pathway to apoptosis. 4. A putative target protein appears to be p34cdc2 which is regulated by a network of kinases and phosphatases. The uncoupling of timing for p34cdc2 activation and the completion of DNA replication results in the so-called "mitotic catastrophe" that shares some features with apoptosis.
Lucas
M
M
Departamento de Bioquímica Médica y Biología Molecular, Hospital Universitario Virgen Macarena, Facultad de Medicina, Sevilla, Spain.
Sánchez-Margalet
V
V
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D006801:Humans; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology
D011493:Protein Kinase C