Regulation of the dual-function transcription factor Sp3 by SUMO.
In eukaryotes, gene expression is controlled by a relatively small number of regulators. Post-translational modifications dramatically increase the functional possibilities of those regulators. Modification of many transcription factors and cofactors by SUMO (small ubiquitin-related modifier) correlates, in most cases, with inhibition of transcription. Recent studies suggest a model whereby SUMO conjugation to transcription factors promotes the recruitment of co-repressors through direct protein-protein interaction with the SUMO protein. HDACs (histone deacetylases) are important, but not exclusive, effectors of SUMO-mediated repression. Sp3 (specificity protein 3), a zinc-finger DNA-binding domain transcription factor, has the ability to both activate and repress transcription in a context-dependent manner. SUMOylation regulates the dual nature of Sp3 function. Current data suggest that Sp3 represses transcription in a SUMO-dependent manner but independent of HDACs. Recent studies to identify additional co-repressors associated with SUMO and further investigate regulated activity of Sp3 are providing a deeper understanding of SUMO-dependent mechanisms of transcriptional regulation.
Valin
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Department of Anatomy and Cellular Biology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA.
Gill
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D006655:Histone Deacetylases / Q000378:metabolism; D025841:Small Ubiquitin-Related Modifier Proteins / Q000378:metabolism*; D051705:Sp3 Transcription Factor / Q000378:metabolism*; D014158:Transcription, Genetic / Q000235:genetics / Q000502:physiology
D025841:Small Ubiquitin-Related Modifier Proteins; D051705:Sp3 Transcription Factor; D006655:Histone Deacetylases