title: New Face for Chromatin-Related Mesenchymal Modulator: n-CHD9 Localizes to Nucleoli and Interacts With Ribosomal Genes.
abstract: Mesenchymal stem cells' differentiation into several lineages is coordinated by a complex of transcription factors and co-regulators which bind to specific gene promoters. The Chromatin-Related Mesenchymal Modulator, CHD9 demonstrated in vitro its ability for remodeling activity to reposition nucleosomes in an ATP-dependent manner. Epigenetically, CHD9 binds with modified H3-(K9me2/3 and K27me3). Previously, we presented a role for CHD9 with RNA Polymerase II (Pol II)-dependent transcription of tissue specific genes. Far less is known about CHD9 function in RNA Polymerase I (Pol I) related transcription of the ribosomal locus that also drives specific cell fate. We here describe a new form, the nucleolar CHD9 (n-CHD9) that is dynamically associated with Pol I, fibrillarin, and upstream binding factor (UBF) in the nucleoli, as shown by imaging and molecular approaches. Inhibitors of transcription disorganized the nucleolar compartment of transcription sites where rDNA is actively transcribed. Collectively, these findings link n-CHD9 with RNA pol I transcription in fibrillar centers. Using chromatin immunoprecipitation (ChIP) and tilling arrays (ChIP- chip), we find an association of n-CHD9 with Pol I related to rRNA biogenesis. Our new findings support the role for CHD9 in chromatin regulation and association with rDNA genes, in addition to its already known function in transcription control of tissue specific genes.
authors.affiliation: Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel.|Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, Bethesda, Maryland.
authors.forename: Ronit
authors.initials: R
authors.lastname: Salomon-Kent
authors.affiliation: Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel.|Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, Bethesda, Maryland.
authors.forename: Ronit
authors.initials: R
authors.lastname: Marom
authors.affiliation: Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, Bethesda, Maryland.
authors.forename: Sam
authors.initials: S
authors.lastname: John
authors.affiliation: Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, Bethesda, Maryland.
authors.forename: Miroslav
authors.initials: M
authors.lastname: Dundr
authors.affiliation: Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, Bethesda, Maryland.
authors.forename: Louis R
authors.initials: LR
authors.lastname: Schiltz
authors.affiliation: Stowers Institute for Medical Research, Kansas City, Missouri.
authors.forename: Jose
authors.initials: J
authors.lastname: Gutierrez
authors.affiliation: Stowers Institute for Medical Research, Kansas City, Missouri.
authors.forename: Jerry
authors.initials: J
authors.lastname: Workman
authors.affiliation: Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel.
authors.forename: Dafna
authors.initials: D
authors.lastname: Benayahu
authors.affiliation: Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, Bethesda, Maryland.
authors.forename: Gordon L
authors.initials: GL
authors.lastname: Hager
mesh_terms: D000818:Animals; D019556:COS Cells; D002454:Cell Differentiation / Q000235:genetics*; D019070:Cell Lineage; D002466:Cell Nucleolus / Q000235:genetics / Q000378:metabolism; D002522:Chlorocebus aethiops; D002843:Chromatin / Q000235:genetics; D004265:DNA Helicases; D004275:DNA, Ribosomal / Q000235:genetics*; D005786:Gene Expression Regulation; D020459:Genes, rRNA; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D035463:Pol1 Transcription Initiation Complex Proteins / Q000235:genetics / Q000378:metabolism; D012318:RNA Polymerase I / Q000235:genetics / Q000378:metabolism; D012270:Ribosomes / Q000235:genetics; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism
chemical_list: D002843:Chromatin; D004275:DNA, Ribosomal; D035463:Pol1 Transcription Initiation Complex Proteins; D015534:Trans-Activators; C063844:transcription factor UBF; D012318:RNA Polymerase I; D004265:DNA Helicases; C511083:Chd9 protein, mouse