title: Caspase-3-mediated cleavage of the NF-kappa B subunit p65 at the NH2 terminus potentiates naphthoquinone analog-induced apoptosis.
abstract: The transcription factor nuclear factor kappaB (NF-kappaB) plays a crucial role in immune and inflammatory response, and protects cells from apoptosis. In this report, we investigate whether the NF-kappaB signaling pathway is blocked during apoptosis induced by 2,3-dichloro-5,8-dihydroxy-1,4-naphthoquinone (NA), an analog of naphthoquinone. It is observed that NA triggers apoptotic cell death in HeLa cells and destroys resistance to apoptosis caused by tumor necrosis factor-alpha. Data presented in this study establish that p65/RelA, a subunit of NF-kappaB, is cleaved at Asp(97) by caspase-3 during apoptosis. Caspase-3-cleaved p65 loses transcriptional activity and potentiates NA-induced apoptosis, in contrast to an uncleavable mutant of p65, which protects the cell from apoptosis. Caspase-3, which is responsible for the cleavage of p65, is activated via the cytochrome c/caspase-9 signaling pathway rather than Fas/caspase-8 pathway during NA-induced apoptosis. Our results suggest that NA induces apoptosis by the negative regulation of cell survival through caspase-3-mediated cleavage of p65.
authors.affiliation: Department of Biology, College of Natural Sciences, College of Pharmacy, Chung-Ang University, Heukseuk Dong, Dongjak Ku, Seoul 156-756, Korea.
authors.forename: K H
authors.initials: KH
authors.lastname: Kang
authors.forename: K H
authors.initials: KH
authors.lastname: Lee
authors.forename: M Y
authors.initials: MY
authors.lastname: Kim
authors.forename: K H
authors.initials: KH
authors.lastname: Choi
mesh_terms: D017209:Apoptosis; D001224:Aspartic Acid / Q000378:metabolism; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism*; D002455:Cell Division; D004591:Electrophoresis, Polyacrylamide Gel; D006367:HeLa Cells; D006801:Humans; D016328:NF-kappa B / Q000378:metabolism*; D009285:Naphthoquinones / Q000494:pharmacology*; D009842:Oligopeptides / Q000494:pharmacology; D051996:Transcription Factor RelA; D014158:Transcription, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D016328:NF-kappa B; D009285:Naphthoquinones; D009842:Oligopeptides; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha; C099158:acetyl-aspartyl-glutamyl-valyl-aspartal; D001224:Aspartic Acid; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases