title: The nonhistone, N-terminal tail of an essential, chimeric H2A variant regulates mitotic H3-S10 dephosphorylation.
abstract: H2A.Y is an essential, divergent Tetrahymena thermophila histone variant. It has a long nonhistone N terminus that contains leucine-rich repeats (LRR) and an LRR cap domain with similarity to Sds22p, a regulator of yeast protein phosphatase 1 (PP1) activity in the nucleus. In growing cells, H2A.Y is incorporated into micronuclei only during S phase, which occurs immediately after micronuclear mitosis. Depletion of H2A.Y causes prolonged retention of mitosis-associated histone H3-S10 phosphorylation and mitotic abnormalities that mimic S10E mutation. In cells where H2A.Y is depleted, an inducible chimeric gene, in which the H2A.Y N terminus is attached to H2A.X, is shown to regulate micronuclear H3-S10 phosphorylation. H2A.Y can also be specifically coimmunoprecipitated with a Tetrahymena PP1 ortholog (Ppo1p). Taken together, these results argue that the N terminus of H2A.Y functions to regulate H3-S10 dephosphorylation. This striking in vivo case of "cross-talk" between a H2A variant and a specific post-translational modification of another histone demonstrates a novel function for a histone variant.
authors.affiliation: Department of Biology, University of Rochester, Rochester, New York 14627, USA.
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Song
authors.forename: Josephine
authors.initials: J
authors.lastname: Bowen
authors.forename: Wei
authors.initials: W
authors.lastname: Miao
authors.forename: Yifan
authors.initials: Y
authors.lastname: Liu
authors.forename: Martin A
authors.initials: MA
authors.lastname: Gorovsky
mesh_terms: D000595:Amino Acid Sequence; D004261:DNA Replication; D055786:Gene Knockout Techniques; D006657:Histones / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D008938:Mitosis; D008969:Molecular Sequence Data; D050506:Mutant Chimeric Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D009707:Nucleosomes / Q000378:metabolism; D010766:Phosphorylation; D010802:Phylogeny; D054645:Protein Phosphatase 1 / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D016808:Tetrahymena thermophila / Q000166:cytology* / Q000378:metabolism*; D018631:ras Proteins / Q000378:metabolism
chemical_list: D006657:Histones; D050506:Mutant Chimeric Proteins; D009707:Nucleosomes; D029701:Saccharomyces cerevisiae Proteins; D054645:Protein Phosphatase 1; C489015:RAS2 protein, S cerevisiae; D018631:ras Proteins