title: Mitogen-induced distinct epialleles are phosphorylated at either H3S10 or H3S28, depending on H3K27 acetylation.
abstract: Stimulation of the MAPK pathway results in mitogen- and stress-activated protein kinase 1/2 (MSK1/2)-catalyzed phosphorylation of histone H3 at serine 10 or 28 and expression of immediate-early (IE) genes. In 10T1/2 mouse fibroblasts, phosphorylation of H3S10 and H3S28 occurs on different H3 molecules and in different nuclear regions. Similarly, we show that mitogen-induced H3S10 and H3S28 phosphorylation occurs in separate pools in human primary fibroblasts. High-resolution imaging studies on both cell types reveal that H3S10 and H3S28 phosphorylation events can be induced in a single cell but on different alleles, giving rise to H3S10ph and H3S28ph epialleles. Coimmunoprecipitation and inhibition studies demonstrate that CBP/p300-mediated H3K27 acetylation is required for MSK1/2 to phosphorylate S28. Although the K9ac and S10ph marks coexist on H3, S10 phosphorylation is not dependent on K9 acetylation by PCAF. We propose that random targeting of H3S10 or H3S28 results from the stochastic acetylation of H3 by CBP/p300 or PCAF, a process comparable to transcriptional bursting causing temporary allelic imbalance. In 10T1/2 cells expressingJun, at least two of three alleles per cell were induced, a sign of high expression level. The redundant roles of H3S10ph and H3S28ph might enable rapid and efficient IE gene induction.
authors.affiliation: Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB R3E 3P4, Canada.
authors.forename: Dilshad H
authors.initials: DH
authors.lastname: Khan
authors.affiliation: Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB R3E 3P4, Canada.
authors.forename: Shannon
authors.initials: S
authors.lastname: Healy
authors.affiliation: Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB R3E 3P4, Canada.
authors.forename: Shihua
authors.initials: S
authors.lastname: He
authors.affiliation: Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB R3E 3P4, Canada.
authors.forename: Daniel
authors.initials: D
authors.lastname: Lichtensztejn
authors.affiliation: Research Institute in Oncology and Hematology, CancerCare Manitoba, Winnipeg, MB R3E 0V9, Canada.
authors.forename: Ludger
authors.initials: L
authors.lastname: Klewes
authors.affiliation: Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB R3E 3P4, Canada.
authors.forename: Kiran L
authors.initials: KL
authors.lastname: Sharma
authors.affiliation: Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB R3E 3P4, Canada.
authors.forename: Veronica
authors.initials: V
authors.lastname: Lau
authors.affiliation: Research Institute in Oncology and Hematology, CancerCare Manitoba, Winnipeg, MB R3E 0V9, Canada.
authors.forename: Sabine
authors.initials: S
authors.lastname: Mai
authors.affiliation: Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB R3E 3P4, Canada.
authors.forename: Geneviève P
authors.initials: GP
authors.lastname: Delcuve
authors.affiliation: Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB R3E 3P4, Canada Jim.Davie@umanitoba.ca.
authors.forename: James R
authors.initials: JR
authors.lastname: Davie
mesh_terms: D000107:Acetylation; D000818:Animals; D018929:Cell Culture Techniques; D005347:Fibroblasts; D006657:Histones / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D051379:Mice; D048055:Mitogen-Activated Protein Kinase 8 / Q000378:metabolism; D010766:Phosphorylation; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D011499:Protein Processing, Post-Translational; D038744:Ribosomal Protein S6 Kinases, 90-kDa / Q000378:metabolism; D012694:Serine; D015533:Transcriptional Activation
chemical_list: D006657:Histones; D012694:Serine; C115634:RPS6KA4 protein, human; D038744:Ribosomal Protein S6 Kinases, 90-kDa; C116919:mitogen and stress-activated protein kinase 1; D048055:Mitogen-Activated Protein Kinase 8