Abstract
The morphology and composition of subnuclear organelles, such as Cajal bodies (CBs), nucleoli, and other nuclear bodies, is dynamic and can change in response to a variety of cell stimuli, including stress. We show that UV-C irradiation disrupts CBs and alters the distribution of a specific subset of CB components. The effect of UV-C on CBs differs from previously reported effects of transcription inhibitors. We demonstrate that the mechanism underlying the response of CBs to UV-C is mediated, at least in part, by PA28? (proteasome activator subunit ?). The presence of PA28? in coilin-containing complexes is increased by UV-C. Overexpression of PA28?, in the absence of UV-C treatment, provokes a similar redistribution of the same subset of CB components that respond to UV-C. RNA interference–mediated knockdown of PA28? attenuates the nuclear disruption caused by UV-C. These data demonstrate that CBs are specific nuclear targets of cellular stress-response pathways and identify PA28? as a novel regulator of CB integrity.
© 2006 Cioce et al. This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.jcb.org/misc/terms.shtml). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/).
Original language | English |
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Pages (from-to) | 401-413 |
Number of pages | 13 |
Journal | Journal of Cell Biology |
Volume | 175 |
Issue number | 3 |
DOIs | |
Publication status | Published - 6 Nov 2006 |