title: End-targeting proteomics of isolated chromatin segments of a mammalian ribosomal RNA gene promoter.
abstract: The unbiased identification of proteins associated with specific loci is crucial for understanding chromatin-based processes. The proteomics of isolated chromatin fragment (PICh) method has previously been developed to purify telomeres and identify associated proteins. This approach is based on the affinity capture of endogenous chromatin segments by hybridization with oligonucleotide containing locked nucleic acids. However, PICh is only efficient with highly abundant genomic targets, limiting its applicability. Here we develop an approach for identifying factors bound to the promoter region of the ribosomal RNA genes that we call end-targeting PICh (ePICh). Using ePICh, we could specifically enrich the RNA polymerase I pre-initiation complex, including the selectivity factor 1. The high purity of the ePICh material allowed the identification of ZFP106, a novel factor regulating transcription initiation by targeting RNA polymerase I to the promoter. Our results demonstrate that ePICh can uncover novel proteins controlling endogenous regulatory elements in mammals.
authors: Inserm Avenir: 'Biology of repetitive sequences'-Institute of Human Genetics, CNRS UPR1142, 141, rue de la Cardonille, Montpellier 34396, France.
authors: Satoru
authors: S
authors: Ide
authors: Inserm Avenir: 'Biology of repetitive sequences'-Institute of Human Genetics, CNRS UPR1142, 141, rue de la Cardonille, Montpellier 34396, France.
authors: Jerome
authors: J
authors: Dejardin
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000818:Animals; D045744:Cell Line, Tumor; D002843:Chromatin / Q000235:genetics*; D047369:Chromatin Immunoprecipitation; D020459:Genes, rRNA / Q000235:genetics*; D051379:Mice; D011401:Promoter Regions, Genetic / Q000235:genetics*; D040901:Proteomics; D012318:RNA Polymerase I / Q000235:genetics*; D061785:Transcription Initiation, Genetic
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002843:Chromatin; C116200:Zfp106 protein, mouse; D012318:RNA Polymerase I