title: Regulation of cell cycle progression and gene expression by H2A deubiquitination.
abstract: Post-translational histone modifications have important regulatory roles in chromatin structure and function. One example of such modifications is histone ubiquitination, which occurs predominately on histone H2A and H2B. Although the recent identification of the ubiquitin ligase for histone H2A has revealed important roles for H2A ubiquitination in Hox gene silencing as well as in X-chromosome inactivation, the enzyme(s) involved in H2A deubiquitination and the function of H2A deubiquitination are not known. Here we report the identification and functional characterization of the major deubiquitinase for histone H2A, Ubp-M (also called USP16). Ubp-M prefers nucleosomal substrates in vitro, and specifically deubiquitinates histone H2A but not H2B in vitro and in vivo. Notably, knockdown of Ubp-M in HeLa cells results in slow cell growth rates owing to defects in the mitotic phase of the cell cycle. Further studies reveal that H2A deubiquitination by Ubp-M is a prerequisite for subsequent phosphorylation of Ser 10 of H3 and chromosome segregation when cells enter mitosis. Furthermore, we demonstrate that Ubp-M regulates Hox gene expression through H2A deubiquitination and that blocking the function of Ubp-M results in defective posterior development in Xenopus laevis. This study identifies the major deubiquitinase for histone H2A and demonstrates that H2A deubiquitination is critically involved in cell cycle progression and gene expression.
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Kaul Human Genetics Building 402A, 720 South 20th Street, Birmingham, Alabama 35294, USA.
authors.forename: Heui-Yun
authors.initials: HY
authors.lastname: Joo
authors.forename: Ling
authors.initials: L
authors.lastname: Zhai
authors.forename: Chunying
authors.initials: C
authors.lastname: Yang
authors.forename: Shuyi
authors.initials: S
authors.lastname: Nie
authors.forename: Hediye
authors.initials: H
authors.lastname: Erdjument-Bromage
authors.forename: Paul
authors.initials: P
authors.lastname: Tempst
authors.forename: Chenbei
authors.initials: C
authors.lastname: Chang
authors.forename: Hengbin
authors.initials: H
authors.lastname: Wang
mesh_terms: D000818:Animals; D002453:Cell Cycle / Q000502:physiology*; D002455:Cell Division; D010450:Endopeptidases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D005801:Genes, Homeobox / Q000235:genetics; D006367:HeLa Cells; D006657:Histones / Q000737:chemistry / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000235:genetics; D006801:Humans; D010768:Phosphoserine / Q000378:metabolism; D013379:Substrate Specificity; D014157:Transcription Factors / Q000235:genetics; D043222:Ubiquitin Thiolesterase / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D054875:Ubiquitination; D029867:Xenopus Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D014982:Xenopus laevis / Q000196:embryology / Q000235:genetics
chemical_list: D006657:Histones; D018398:Homeodomain Proteins; D014157:Transcription Factors; C118778:USP16 protein, human; C524417:Usp16 protein, Xenopus; D029867:Xenopus Proteins; C072064:HOXD10 protein, human; D010768:Phosphoserine; D010450:Endopeptidases; D043222:Ubiquitin Thiolesterase; C091939:ubiquitin isopeptidase