title: An acetylation-mono-ubiquitination switch on lysine 120 of H2B.
abstract: Post-translational modifications (PTMs) of histones are crucial for transcriptional control, defining positive and negative chromatin territories. A switch of opposing functional significance between acetylation and methylation occurs on many residues. Lysine 120 of H2B is modified by two PTMs: ubiquitination, which is required for further trans-tail H3 methylations and elongation, and acetylation, whose role is less clear. ChIP-Seq with MNase I-treated chromatin indicates that H2BK120ac is present on nucleosomes immediately surrounding the TSS of transcribed or poised units, but not in core promoters. In kinetic ChIP analysis of ER-stress inducible genes, H2BK120ac precedes activation and H2B-ub deposition. Using in vitro acetylation assays, pharmacologic inhibition and RNAi, we established that KAT3 is responsible for H2BK120ac. Interestingly, the global levels of H2B-ub decreased in KAT3-inactivated cells. However, RNF20 recruitment was not impaired by KAT3-inactivation. Our data point at acetylation of Lysine 120 of H2B as an early mark of poised or active state and establish a temporal sequence between acetylation and mono-ubiquitination of this H2B residue.
authors: Dipartimento de Scienze Biomolecolari e Biotecnologie, Università degli Studi di Milano, Milano, Italy.
authors: Raffaella
authors: R
authors: Gatta
authors: Diletta
authors: D
authors: Dolfini
authors: Federico
authors: F
authors: Zambelli
authors: Carol
authors: C
authors: Imbriano
authors: Giulio
authors: G
authors: Pavesi
authors: Roberto
authors: R
authors: Mantovani
mesh_terms: D000107:Acetylation; D002843:Chromatin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D045325:HCT116 Cells; D056945:Hep G2 Cells; D006657:Histones / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008239:Lysine / Q000737:chemistry / Q000378:metabolism*; D008745:Methylation; D009707:Nucleosomes / Q000235:genetics / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D044767:Ubiquitin-Protein Ligases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D054875:Ubiquitination
chemical_list: D002843:Chromatin; D006657:Histones; D009707:Nucleosomes; C506646:RNF20 protein, human; D044767:Ubiquitin-Protein Ligases; D008239:Lysine