title: Alteration/Deficiency in Activation 3 (ADA3) Protein, a Cell Cycle Regulator, Associates with the Centromere through CENP-B and Regulates Chromosome Segregation.
abstract: ADA3 (alteration/deficiency in activation 3) is a conserved component of several transcriptional co-activator and histone acetyltransferase (HAT) complexes. Recently, we generated Ada3 knock-out mice and demonstrated that deletion of Ada3 leads to early embryonic lethality. The use of Ada3(FL/FL) mouse embryonic fibroblasts with deletion of Ada3 using adenovirus Cre showed a critical role of ADA3 in cell cycle progression through mitosis. Here, we demonstrate an association of ADA3 with the higher order repeat region of the α-satellite region on human X chromosome centromeres that is consistent with its role in mitosis. Given the role of centromere proteins (CENPs) in mitosis, we next analyzed whether ADA3 associates with the centromere through CENPs. Both an in vivo proximity ligation assay and immunofluorescence studies confirmed the association of ADA3 with CENP-B protein, a highly conserved centromeric protein that binds to the 17-bp DNA sequences on α-satellite DNA. Deletional analysis showed that ADA3 directly associates with CENP-B through its N terminus, and a CENP-B binding-deficient mutant of ADA3 was incompetent in cell proliferation rescue. Notably, knockdown of ADA3 decreased binding of CENP-B onto the centromeres, suggesting that ADA3 is required for the loading of CENP-B onto the centromeres. Finally, we show that deletion of Ada3 from Ada3(FL/FL) mouse embryonic fibroblasts exhibited various chromosome segregation defects. Taken together, we demonstrate a novel ADA3 interaction with CENP-B-centromere that may account for its previously known function in mitosis. This study, together with its known function in maintaining genomic stability and its mislocalization in cancers, suggests an important role of ADA3 in mitosis.
authors.affiliation: Department of Genetics, Cell Biology, and Anatomy.
authors.forename: Shakur
authors.initials: S
authors.lastname: Mohibi
authors.affiliation: Department of Genetics, Cell Biology, and Anatomy.
authors.forename: Shashank
authors.initials: S
authors.lastname: Srivastava
authors.affiliation: Department of Genetics, Cell Biology, and Anatomy.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang-France
authors.affiliation: Department of Genetics, Cell Biology, and Anatomy.
authors.forename: Sameer
authors.initials: S
authors.lastname: Mirza
authors.affiliation: Department of Genetics, Cell Biology, and Anatomy.
authors.forename: Xiangshan
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Department of Genetics, Cell Biology, and Anatomy; Departments of Biochemistry and Molecular Biology, Pathology and Microbiology, and Pharmacology and Experimental Neuroscience, College of Medicine; Eppley Institute for Cancer and Allied Diseases; Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, 985805 Nebraska Medical Center, Omaha, Nebraska 68198. Electronic address: vband@unmc.edu.
authors.forename: Hamid
authors.initials: H
authors.lastname: Band
authors.affiliation: Department of Genetics, Cell Biology, and Anatomy; Eppley Institute for Cancer and Allied Diseases; Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, 985805 Nebraska Medical Center, Omaha, Nebraska 68198.
authors.forename: Vimla
authors.initials: V
authors.lastname: Band
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002503:Centromere; D051936:Centromere Protein B / Q000502:physiology*; D020090:Chromosome Segregation; D051379:Mice; D008938:Mitosis / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D014960:X Chromosome
chemical_list: D051936:Centromere Protein B; C580756:Tada3 protein, mouse; D014157:Transcription Factors
keywords: ADA3; ATAC; CENP-B; SAGA; cell cycle; centromere; chromatin immunoprecipitation (ChIP); chromosome segregation; mitosis; transcriptional coactivator