6533b826fe1ef96bd1283d83
RESEARCH PRODUCT
Heat shock protein 27 is involved in SUMO-2/3 modification of heat shock factor 1 and thereby modulates the transcription factor activity
Guillaume BossisGuillaume BossisM Brunet SimioniJacques LandryCarmen GarridoCarmen GarridoA De ThonelA De ThonelMarc PiechaczykMarc PiechaczykA BouchotEric FourmauxArlette HammannArlette HammannAnne-laure JolyAnne-laure Jolysubject
Protein sumoylationTranscriptional ActivationCancer Researchendocrine systemanimal structuresSUMO proteinHSP27 Heat-Shock ProteinsBiologyurologic and male genital diseasesenvironment and public healthSubstrate Specificity03 medical and health sciencesTransactivation0302 clinical medicineHeat Shock Transcription FactorsHeat shock proteinGeneticsAnimalsHumansAnimals Cell Nucleus/metabolism DNA-Binding Proteins/*metabolism HSP27 Heat-Shock Proteins/chemistry/*metabolism Hela Cells Humans Protein Multimerization Protein Structure[SDV.BBM]Life Sciences [q-bio]/Biochemistry Molecular BiologyHSF1Protein Structure QuaternaryMolecular BiologyTranscription factorUbiquitinsHeat-Shock Proteins030304 developmental biologyCell Nucleus0303 health sciencesMolecular biologyHsp70Cell biologyHeat shock factorDNA-Binding ProteinsProtein TransportQuaternary Protein Transport Small Ubiquitin-Related Modifier Proteins/*metabolism Substrate Specificity Transcription Factors/*metabolism Transcriptional Activation Ubiquitins/*metabolism030220 oncology & carcinogenesisembryonic structuresSmall Ubiquitin-Related Modifier ProteinsProtein MultimerizationHeLa CellsMolecular ChaperonesTranscription Factorsdescription
Heat shock protein 27 (HSP27) accumulates in stressed cells and helps them to survive adverse conditions. We have already shown that HSP27 has a function in the ubiquitination process that is modulated by its oligomerization/phosphorylation status. Here, we show that HSP27 is also involved in protein sumoylation, a ubiquitination-related process. HSP27 increases the number of cell proteins modified by small ubiquitin-like modifier (SUMO)-2/3 but this effect shows some selectivity as it neither affects all proteins nor concerns SUMO-1. Moreover, no such alteration in SUMO-2/3 conjugation is achievable by another HSP, such as HSP70. Heat shock factor 1 (HSF1), a transcription factor responsible for HSP expression, is one of the targets of HSP27. In stressed cells, HSP27 enters the nucleus and, in the form of large oligomers, binds to HSF1 and induces its modification by SUMO-2/3 on lysine 298. HSP27-induced HSF1 modification by SUMO-2/3 takes place downstream of the transcription factor phosphorylation on S303 and S307 and does not affect its DNA-binding ability. In contrast, this modification blocks HSF1 transactivation capacity. These data show that HSP27 exerts a feedback inhibition of HSF1 transactivation and enlighten the strictly regulated interplay between HSPs and HSF1. As we also show that HSP27 binds to the SUMO-E2-conjugating enzyme, Ubc9, our study raises the possibility that HSP27 may act as a SUMO-E3 ligase specific for SUMO-2/3.
year | journal | country | edition | language |
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2009-01-01 |