First published online September 26, 2003
Journal of Cell Science 116, e2102 (2003)
Copyright © 2003 The Company of Biologists Limited
PML bodies SUMO wrestle
Nuclei contain a variety of dynamic subcompartments. These include nucleoli, so-called `nuclear speckles', Cajal (coiled) bodies and PML bodies – structures that contain the promyelocytic leukaemia protein (PML). PML bodies dissociate to form numerous microstructures in response to stress and might function in gene regulation or as nuclear storage sites. Whether they indeed have a specific role or are simply random aggregations of protein is debated, however. David Bazett-Jones and co-workers have therefore analysed dissociation and reassembly of PML bodies in live cells responding to stress (see p. 4455). The authors observe that the compartments dissociate by fission/budding and re-form at their original locations; moreover, their relative sizes are preserved when they reassemble. This indicates that PML bodies assemble at specific sites to a specific size. The authors also find that the dissociated microstructures lack the small ubiquitin-like modifier (SUMO), which reappears as they assemble. In addition, they demonstrate that overexpression of SUMO blocks stress-induced disassembly of PML bodies. Their findings thus not only reveal that PML bodies are not just random aggregates but suggest that SUMO regulates their integrity.
Related articles in JCS:
- Size, position and dynamic behavior of PML nuclear bodies following cell stress as a paradigm for supramolecular trafficking and assembly
- Christopher H. Eskiw, Graham Dellaire, Joe S. Mymryk, and David P. Bazett-Jones
JCS 2003 116: 4455-4466.
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