title: Nuclear myosin 1 contributes to a chromatin landscape compatible with RNA polymerase II transcription activation.
abstract: BACKGROUND
  Nuclear myosin 1c (NM1) is emerging as a regulator of transcription and chromatin organization.
  
  
  RESULTS
  Using chromatin immunoprecipitation and deep sequencing (ChIP-Seq) in combination with molecular analyses, we investigated the global association of NM1 with the mammalian genome. Analysis of the ChIP-Seq data demonstrates that NM1 binds across the entire mammalian genome with occupancy peaks correlating with distributions of RNA Polymerase II (Pol II) and active epigenetic marks at class II gene promoters. In mouse embryonic fibroblasts subjected to RNAi mediated NM1 gene silencing, we show that NM1 synergizes with polymerase-associated actin to maintain active Pol II at the promoter. NM1 also co-localizes with the nucleosome remodeler SNF2h at class II promoters where they assemble together with WSTF as part of the B-WICH complex. A high resolution micrococcal nuclease (MNase) assay and quantitative real time PCR shows that this mechanism is required for local chromatin remodeling. Following B-WICH assembly, NM1 mediates physical recruitment of the histone acetyl transferase PCAF and the histone methyl transferase Set1/Ash2 to maintain and preserve H3K9acetylation and H3K4trimethylation for active transcription.
  
  
  CONCLUSIONS
  We propose a novel genome-wide mechanism where myosin synergizes with Pol II-associated actin to link the polymerase machinery with permissive chromatin for transcription activation.
authors.affiliation: Department of Cell and Molecular Biology, Karolinska Institute, Box 285, SE-171 77, Stockholm, Sweden. bader.almuzzaini@ki.se.
authors.forename: Bader
authors.initials: B
authors.lastname: Almuzzaini
authors.affiliation: Department of Cell and Molecular Biology, Karolinska Institute, Box 285, SE-171 77, Stockholm, Sweden. aishe.angelettisarshad@nih.gov.|Present address: National Institute of Health, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD, 20892-3675, USA. aishe.angelettisarshad@nih.gov.
authors.forename: Aishe A
authors.initials: AA
authors.lastname: Sarshad
authors.affiliation: Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91, Stockholm, Sweden. anki.ostlund@su.se.
authors.forename: Ann-Kristin Östlund
authors.initials: AK
authors.lastname: Farrants
authors.affiliation: Department of Cell and Molecular Biology, Karolinska Institute, Box 285, SE-171 77, Stockholm, Sweden. piergiorgio.percipalle@ki.se.
authors.forename: Piergiorgio
authors.initials: P
authors.lastname: Percipalle
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism*; D042002:Chromatin Assembly and Disassembly; D005347:Fibroblasts / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D051379:Mice; D024461:Myosin Type I / Q000235:genetics* / Q000378:metabolism; D011485:Protein Binding; D012319:RNA Polymerase II / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation / Q000235:genetics*
chemical_list: D002843:Chromatin; C470422:Myo1c protein, mouse; D012319:RNA Polymerase II; D024461:Myosin Type I