Apoptosis is a highly coordinated cell suicide mechanism in vertebrates. Phosphorylation of serine 14 of histone H2B, catalyzed by Mst1 kinase, has been linked to chromatin compaction during apoptosis. We extend these results to unicellular eukaryotes by demonstrating that H2B is specifically phosphorylated at serine 10 (S10) in a hydrogen peroxide-induced cell death pathway in S. cerevisiae. H2B S10A mutants are resistant to cell death elicited by H(2)O(2) while H2B S10E phospho-site mimics promote cell death and induce the "constitutive" formation of condensed chromatin. Ste20 kinase, a yeast homolog of mammalian Mst1 kinase, translocates into the nucleus in a caspase-independent fashion and directly phosphorylates H2B at S10. Conservation of targeted H2B phosphorylation and the enzyme system responsible for the process point to an ancient mechanism of chromatin remodeling that likely plays an important role in governing cellular homeostasis in a wide range of organisms.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Reference||Annotation Extension|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Conditions||Strain||Source||Reference|