Small Ubiquitin-like Modifier (SUMO) Conjugation Impedes Transcriptional Silencing by the Polycomb Group Repressor Sex Comb on Midleg
Autor: | Albert J. Courey, Matthew M. Smith, Jeffrey A. Simon, Daniel R. Mallin |
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Rok vydání: | 2011 |
Předmět: |
animal structures
Transcription Genetic Amino Acid Motifs SUMO-1 Protein SUMO protein Polycomb-Group Proteins Repressor macromolecular substances Ubiquitin-conjugating enzyme Response Elements Biochemistry Cell Line Ubiquitin Polycomb-group proteins Animals Drosophila Proteins Gene Regulation Gene Silencing Molecular Biology Transcription factor Ultrabithorax Homeodomain Proteins Genetics Binding Sites biology fungi Sumoylation Cell Biology Repressor Proteins Drosophila melanogaster Ubiquitin-Conjugating Enzymes embryonic structures biology.protein Homeotic gene Transcription Factors |
Zdroj: | Journal of Biological Chemistry. 286:11391-11400 |
ISSN: | 0021-9258 |
DOI: | 10.1074/jbc.m110.214569 |
Popis: | The Drosophila protein Sex Comb on Midleg (Scm) is a member of the Polycomb group (PcG), a set of transcriptional repressors that maintain silencing of homeotic genes during development. Recent findings have identified PcG proteins both as targets for modification by the small ubiquitin-like modifier (SUMO) protein and as catalytic components of the SUMO conjugation pathway. We have found that the SUMO-conjugating enzyme Ubc9 binds to Scm and that this interaction, which requires the Scm C-terminal sterile α motif (SAM) domain, is crucial for the efficient sumoylation of Scm. Scm is associated with the major Polycomb response element (PRE) of the homeotic gene Ultrabithorax (Ubx), and efficient PRE recruitment requires an intact Scm SAM domain. Global reduction of sumoylation augments binding of Scm to the PRE. This is likely to be a direct effect of Scm sumoylation because mutations in the SUMO acceptor sites in Scm enhance its recruitment to the PRE, whereas translational fusion of SUMO to the Scm N terminus interferes with this recruitment. In the metathorax, Ubx expression promotes haltere formation and suppresses wing development. When SUMO levels are reduced, we observe decreased expression of Ubx and partial haltere-to-wing transformation phenotypes. These observations suggest that SUMO negatively regulates Scm function by impeding its recruitment to the Ubx major PRE. |
Databáze: | OpenAIRE |
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