Antisense depletion of death-associated protein kinase promotes apoptosis.
Death-associated protein kinases (DAPK) are serine/threonine protein kinases that have an important role in regulating cell death. In this study two antisense approaches were employed to down-regulate expression of the endogenous DAPK-alpha and DAPK-beta proteins. Transient expression of an antisense DAPK cDNA or antisense morpholino oligonucleotides in HeLa, 3T3, or primary human vascular smooth muscle cells demonstrate that decreased DAPK expression promotes a spontaneous, caspase-mediated apoptosis as evidenced by increased activities of caspases-3 and -9. Clonal HeLa cell lines with attenuated levels of DAPK expression, obtained following selection in the presence of antisense DAPK cDNA, are more sensitive to tumor necrosis factor-induced caspase-mediated apoptosis, and their sensitivity is inversely related to DAPK expression. In contrast, HeLa cells with reduced DAPK expression are moderately resistant to cell death induced by interferon-gamma. This finding is consistent with previous studies showing that DAPK has a role in promoting caspase-independent cell death. Together, these studies demonstrate that the cellular activities of DAPK are critical for antagonizing caspase-dependent apoptosis to promote cell survival under normal cell growth conditions.
Jin
Yijun
Y
Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA.
Gallagher
Patricia J
PJ
D000818:Animals; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000187:drug effects / Q000502:physiology*; D020169:Caspases / Q000032:analysis; D002470:Cell Survival; D016373:DNA, Antisense / Q000494:pharmacology*; D064550:Death-Associated Protein Kinases; D015536:Down-Regulation / Q000187:drug effects; D006367:HeLa Cells; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D051379:Mice; D009131:Muscle, Smooth, Vascular / Q000166:cytology; D041681:NIH 3T3 Cells; D020033:Protein Isoforms / Q000187:drug effects / Q000502:physiology; D014162:Transfection
D051017:Apoptosis Regulatory Proteins; D016373:DNA, Antisense; D020033:Protein Isoforms; D007371:Interferon-gamma; D064550:Death-Associated Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D020169:Caspases