Crosstalk between sumoylation and acetylation regulates p53-dependent chromatin transcription and DNA binding

Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390-8807, USA.
The EMBO Journal (Impact Factor: 10.43). 05/2009; 28(9):1246-59. DOI: 10.1038/emboj.2009.83
Source: PubMed


Covalent modification by small ubiquitin-related modifiers (SUMO) regulates p53 transcription activity through an undefined mechanism. Using reconstituted sumoylation components, we purified SUMO-1-conjugated p53 (Su-p53) to near homogeneity. Su-p53 exists in solution as a tetramer and interacts with p300 histone acetyltransferase as efficiently as the unmodified protein. Nevertheless, it fails to activate p53-dependent chromatin transcription because of its inability to bind DNA. With sequential modification assays, we found that sumoylation of p53 at K386 blocks subsequent acetylation by p300, whereas p300-acetylated p53 remains permissive for ensuing sumoylation at K386 and alleviates sumoylation-inhibited DNA binding. While preventing the free form of p53 from accessing its cognate sites, sumoylation fails to disengage prebound p53 from DNA. The sumoylation-deficient K386R protein, when expressed in p53-null cells, exhibits higher transcription activity and binds better to the endogenous p21 gene compared with the wild-type protein. These studies unravel a molecular mechanism underlying sumoylation-regulated p53 function and further uncover a new role of acetylation in antagonizing the inhibitory effect of sumoylation on p53 binding to DNA.

14 Reads
  • Source
    • "In vitro, in-cell, and in vivo SUMO assay For the in vitro SUMO assay, all SUMO components were highly purified as previously described (Wu & Chiang, 2009). Flag-FXR was expressed in COS-1 cells and isolated by binding to M2 agarose. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Acetylation of transcriptional regulators is normally dynamically regulated by nutrient status but is often persistently elevated in nutrient-excessive obesity conditions. We investigated the functional consequences of such aberrantly elevated acetylation of the nuclear receptor FXR as a model. Proteomic studies identified K217 as the FXR acetylation site in diet-induced obese mice. In vivo studies utilizing acetylation-mimic and acetylation-defective K217 mutants and gene expression profiling revealed that FXR acetylation increased proinflammatory gene expression, macrophage infiltration, and liver cytokine and triglyceride levels, impaired insulin signaling, and increased glucose intolerance. Mechanistically, acetylation of FXR blocked its interaction with the SUMO ligase PIASy and inhibited SUMO2 modification at K277, resulting in activation of inflammatory genes. SUMOylation of agonist-activated FXR increased its interaction with NF-κB but blocked that with RXRα, so that SUMO2-modified FXR was selectively recruited to and trans-repressed inflammatory genes without affecting FXR/RXRα target genes. A dysregulated acetyl/SUMO switch of FXR in obesity may serve as a general mechanism for diminished anti-inflammatory response of other transcriptional regulators and provide potential therapeutic and diagnostic targets for obesity-related metabolic disorders. © 2014 The Authors.
    The EMBO Journal 11/2014; 34(2). DOI:10.15252/embj.201489527 · 10.43 Impact Factor
  • Source
    • "Recently, Wu et al demonstrated that sumoylated p53 failed to undergo acetylation, even though the interaction with p300 was still preserved. This suggests that sumoylation of K386 prevents the subsequent acetylation of C-terminal lysines in p53, possibly contributing to a loss of DNA-binding activity of p53, and thus attenuating p53 transcriptional activity [83]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Post-translational modifications provide a fine-tuned control of protein function(s) in the cell. The well-known tumour suppressor p53 is subject to many post-translational modifications, which alter its activity, localization and stability, thus ultimately modulating its response to various forms of genotoxic stress. In this review, we focus on the role of recently discovered lysine-specific modifications of p53, methylation and acetylation in particular, and their effects on p53 activity in damaged cells. We also discuss a possibility of mutual influence of covalent modifications in the p53 and histone proteins located in the vicinity of p53 binding sites in chromatin and propose important ramifications stemming from this hypothesis.
    Oncotarget 10/2013; 4(10):1556-71. DOI:10.18632/oncotarget.1436 · 6.36 Impact Factor
  • Source
    • "The SUMO E3-ligases PIASs have been mainly implicated in the regulation of innate immunity through epigenetic mechanisms (Liu et al., 2004, 2010; Shuai and Liu, 2005; Rytinki et al., 2009). Moreover, it has been suggested that PIAS1 may regulate oncogenic networks through its ability to inhibit tumor suppressors such as p53, BRCA1, and STAT1 (Schmidt and Muller, 2002; Galanty et al., 2009; Wu and Chiang, 2009). Therefore, our work reveled a novel function of PIAS1. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The promyelocytic leukemia tumor suppressor gene (PML) critically regulates several cellular functions that oppose tumorigenesis such as oncogene-induced senescence, apoptosis, the response to DNA damage and to viral infections. PML deficiency occurs commonly in a broad spectrum of human cancers through mechanisms that involve its aberrant ubiquitination and degradation. Furthermore, several viruses encode viral proteins that promote viral replication through degradation of PML. These observations suggest that restoration of PML should lead to potent antitumor effects or antiviral responses. In this review we will summarize the mechanisms involved in PML degradation with the intent to highlight novel therapeutic strategies to trigger PML restoration.
    Frontiers in Oncology 03/2013; 3:60. DOI:10.3389/fonc.2013.00060
Show more

Preview (2 Sources)

14 Reads
Available from