Many cellular processes are regulated by the coordination of several post-translational modifications that allow a very fine modulation of substrates. Recently it has been reported that there is a relationship between sumoylation and ubiquitination. Here we propose that the nucleolus is the key organelle in which SUMO-1 conjugates accumulate in response to proteasome inhibition. We demonstrated that, upon proteasome inhibition, the SUMO-1 nuclear dot localization is redirected to nucleolar structures. To better understand this process we investigated, by quantitative proteomics, the effect of proteasome activity on endogenous nucleolar SUMO-1 targets. 193 potential SUMO-1 substrates were identified, and interestingly in several purified SUMO-1 conjugates ubiquitin chains were found to be present, confirming the coordination of these two modifications. 23 SUMO-1 targets were confirmed by an in vitro sumoylation reaction performed on nuclear substrates. They belong to protein families such as small nuclear ribonucleoproteins, heterogeneous nuclear ribonucleoproteins, ribosomal proteins, histones, RNA-binding proteins, and transcription factor regulators. Among these, histone H1, histone H3, and p160 Myb-binding protein 1A were further characterized as novel SUMO-1 substrates. The analysis of the nature of the SUMO-1 targets identified in this study strongly indicates that sumoylation, acting in coordination with the ubiquitin-proteasome system, regulates the maintenance of nucleolar integrity. © 2009 by The American Society for Biochemistry and Molecular Biology, Inc
Matafora, V., D'Amato, A., Mori, S., Blasi, F., & Bachi, A. (2009). Proteomics analysis of nucleolar SUMO-1 target proteins upon proteasome inhibition. MOLECULAR & CELLULAR PROTEOMICS, 8(10), 2243-2255 [10.1074/mcp.M900079-MCP200].
Citazione: | Matafora, V., D'Amato, A., Mori, S., Blasi, F., & Bachi, A. (2009). Proteomics analysis of nucleolar SUMO-1 target proteins upon proteasome inhibition. MOLECULAR & CELLULAR PROTEOMICS, 8(10), 2243-2255 [10.1074/mcp.M900079-MCP200]. | |
Tipo: | Articolo in rivista - Articolo scientifico | |
Carattere della pubblicazione: | Scientifica | |
Presenza di un coautore afferente ad Istituzioni straniere: | No | |
Titolo: | Proteomics analysis of nucleolar SUMO-1 target proteins upon proteasome inhibition | |
Autori: | Matafora, V; D'Amato, A; Mori, S; Blasi, F; Bachi, A | |
Autori: | ||
Data di pubblicazione: | 2009 | |
Lingua: | English | |
Rivista: | MOLECULAR & CELLULAR PROTEOMICS | |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1074/mcp.M900079-MCP200 | |
Appare nelle tipologie: | 01 - Articolo su rivista |