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Updated: Jul 6, 2026

Chromatin Isolation by RNA Purification (ChIRP)
Published on: March 25, 2012
Identification of SUMO-dependent chromatin-associated transcriptional repression components by a genome-wide RNAi
Bastian Stielow1, Alexandra Sapetschnig, Imme Krüger
1Institute of Molecular Biology and Tumor Research, Philipps-University of Marburg, Emil-Mannkopff-Strasse 2, D-35032 Marburg, Germany.
Abstract:
SUMO modification of many transcription factors is linked to transcriptional repression. The molecular mechanisms by which SUMO attachment represses transcription are largely unknown. Here we report a genome-wide RNA interference screen in Drosophila melanogaster cells for components regulating and mediating SUMO-dependent transcriptional repression. Analysis of >21,000 double-stranded RNAs (dsRNAs) identified 120 genes whose dsRNA-mediated knockdowns impaired SUMO-dependent transcriptional repression. Several of these genes encode chromatin-associated proteins, including the ATP-dependent chromatin remodeler Mi-2, the D. melanogaster ortholog of the C. elegans protein MEP-1, and the polycomb protein Sfmbt. Knockdown of these proteins did not impair SUMO conjugation, demonstrating that they act downstream of SUMO attachment. Biochemical analyses revealed that MEP-1, Mi-2, and Sfmbt interact with each other, bind to SUMO, and are recruited to promoters in a SUMOylation-dependent manner. Our results suggest that MEP-1, Mi-2, and Sfmbt are part of a common repression complex established by DNA-bound SUMO-modified transcription factors.
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