title: Epigenetic regulation of protein-coding and microRNA genes by the Gfi1-interacting tumor suppressor PRDM5.
abstract: Gfi1 transcriptionally governs hematopoiesis, and its mutations produce neutropenia. In an effort to identify Gfi1-interacting proteins and also to generate new candidate genes causing neutropenia, we performed a yeast two-hybrid screen with Gfi1. Among other Gfi1-interacting proteins, we identified a previously uncharacterized member of the PR domain-containing family of tumor suppressors, PRDM5. PRDM5 has 16 zinc fingers, and we show that it acts as a sequence-specific, DNA binding transcription factor that targets hematopoiesis-associated protein-coding and microRNA genes, including many that are also targets of Gfi1. PRDM5 epigenetically regulates transcription similarly to Gfi1: it recruits the histone methyltransferase G9a and class I histone deacetylases to its target gene promoters and demonstrates repressor activity on synthetic reporters; on endogenous target genes, however, it functions as an activator, in addition to a repressor. Interestingly, genes that PRDM5 activates, as opposed to those it represses, are also targets of Gfi1, suggesting a competitive mechanism through which two repressors could cooperate in order to become transcriptional activators. In neutropenic patients, we identified PRDM5 protein sequence variants perturbing transcriptional function, suggesting a potentially important role in hematopoiesis.
authors.affiliation: Division of Medical Genetics, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA.
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Duan
authors.forename: Richard E
authors.initials: RE
authors.lastname: Person
authors.forename: Hu-Hui
authors.initials: HH
authors.lastname: Lee
authors.forename: Shi
authors.initials: S
authors.lastname: Huang
authors.forename: Jean
authors.initials: J
authors.lastname: Donadieu
authors.forename: Raffaele
authors.initials: R
authors.lastname: Badolato
authors.forename: H Leighton
authors.initials: HL
authors.lastname: Grimes
authors.forename: Thalia
authors.initials: T
authors.lastname: Papayannopoulou
authors.forename: Marshall S
authors.initials: MS
authors.lastname: Horwitz
mesh_terms: D002453:Cell Cycle / Q000502:physiology; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D044127:Epigenesis, Genetic; D005786:Gene Expression Regulation; D006410:Hematopoiesis / Q000502:physiology; D056284:Histone Deacetylase 1; D006655:Histone Deacetylases / Q000235:genetics / Q000378:metabolism; D000076983:Histone Methyltransferases; D011495:Histone-Lysine N-Methyltransferase / Q000378:metabolism; D006801:Humans; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009503:Neutropenia / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011496:Protein Methyltransferases; D034622:RNA Interference; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D020798:Two-Hybrid System Techniques; D016335:Zinc Fingers
chemical_list: D004268:DNA-Binding Proteins; C498275:GFI1 protein, human; D035683:MicroRNAs; C487762:PRDM5 protein, human; D014157:Transcription Factors; D000076983:Histone Methyltransferases; D011496:Protein Methyltransferases; D011495:Histone-Lysine N-Methyltransferase; C110550:HDAC1 protein, human; D056284:Histone Deacetylase 1; D006655:Histone Deacetylases