Submitted: 19 April 2004 Accepted: 20 October 2004 Footnotes Abbreviations used in this paper: CAD, caspase-activated DNase CIDE, cell-inducing DFF45-like effector DFF, DNA fragmentation factor FLIP, fluorescence loss induced by photobleaching HMG, high mobility group ICAD, inhibitor of caspase-activated DNase MEF, mouse embryonic fibroblast NuMA, nuclear mitotic apparatus protein STS, staurosporine. We propose a novel paradigm for the regulation of CAD in the nucleus, involving unrestricted accessibility of chromosomal DNA at the initial phase of apoptosis, followed by its nuclear immobilization that may prevent the release of the active nuclease into the extracellular environment. Preventing the nuclear attachment of CAD provoked its extracellular release from apoptotic cells. CAD immobilization was mediated by its NH 2 terminus independently of its DNA-binding activity and correlated with its association to the interchromosomal space. Upon induction of caspase-3вЂ“dependent apoptosis, activated CAD underwent progressive immobilization, paralleled by its attenuated extractability from the nucleus. The CAD-GFP fusion protein complexed with its inhibitor (ICAD) was as mobile as nuclear GFP in the nucleosol of dividing cells. We used fluorescence photobleaching and biochemical techniques to investigate the molecular dynamics of CAD. Lechardeur, Delphine Xu, Ming Lukacs, Gergely L.ДЄlthough compelling evidence supports the central role of caspase-activated DNase (CAD) in oligonucleosomal DNA fragmentation in apoptotic nuclei, the regulation of CAD activity remains elusive in vivo. Contrasting nuclear dynamics of the caspase-activated DNase (CAD) in dividing and apoptotic cells Contrasting nuclear dynamics of the caspase-activated DNase (CAD) in dividing and apoptotic cells

Dna chromatin histone cad icad