title: MAPKs and Mst1/Caspase-3 pathways contribute to H2B phosphorylation during UVB-induced apoptosis.
abstract: Apoptosis is a highly coordinated or programmed cell suicide mechanism in eukaryotes. Histone modification is associated with nuclear events in apoptotic cells. Specifically H2B phosphorylation at serine 14 (Ser14) catalyzed by Mst1 kinase has been linked to chromatin condensation during apoptosis. We report that activation of MAPKs (ERK1/2, JNK1/2 and p38) together with Mst1 and caspase-3 is required for phosphorylation of H2B (Ser14) during ultraviolet B light (UVB)-induced apoptosis. UVB can trigger activation of MAPKs and induce H2B phosphorylation at Ser14 but not acetylation in a time-dependent manner. Inhibition of ERK1/2, JNK1/2 or p38 activity blocked H2B phosphorylation (Ser14). Furthermore, caspase-3 was activated by UVB to regulate Mst1 activity, which phosphorylates H2B at Ser14, leading to chromatin condensation. Full inhibition of caspase-3 activity reduced Mst1 activation and partially inhibited H2B phosphorylation (Ser14), but ERK1/2, JNK1/2 and p38 activities were not affected. Taken together, these data revealed that H2B phosphorylation is regulated by both MAPKs and caspase-3/Mst1 pathways during UVB-induced apoptosis.
authors.affiliation: Aviation Medicine Research Laborabory, General Hospital of Air Force, Beijing, 100142, China. luchengrong@263.net
authors.forename: ChengRong
authors.initials: C
authors.lastname: Lu
authors.forename: Ying
authors.initials: Y
authors.lastname: Shi
authors.forename: Yuan
authors.initials: Y
authors.lastname: Luo
authors.forename: LianNing
authors.initials: L
authors.lastname: Duan
authors.forename: Yong
authors.initials: Y
authors.lastname: Hou
authors.forename: HongBo
authors.initials: H
authors.lastname: Hu
authors.forename: Zhe
authors.initials: Z
authors.lastname: Wang
authors.forename: PeiDe
authors.initials: P
authors.lastname: Xiang
mesh_terms: D000107:Acetylation; D017209:Apoptosis / Q000528:radiation effects*; D015153:Blotting, Western; D053148:Caspase 3 / Q000378:metabolism*; D002478:Cells, Cultured; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006657:Histones / Q000378:metabolism*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D014466:Ultraviolet Rays; D000099317:Hippo Kinases
chemical_list: D053148:Caspase 3; D006657:Histones; D047908:Intracellular Signaling Peptides and Proteins; D020928:Mitogen-Activated Protein Kinases; D017346:Protein Serine-Threonine Kinases; C095566:STK4 protein, human; D000099317:Hippo Kinases