title: Acetylation-dependent nuclear arrangement and recruitment of BMI1 protein to UV-damaged chromatin.
abstract: Polycomb group (PcG) proteins, organized into Polycomb bodies, are important regulatory components of epigenetic processes involved in the heritable transcriptional repression of target genes. Here, we asked whether acetylation can influence the nuclear arrangement and function of the BMI1 protein, a core component of the Polycomb group complex, PRC1. We used time-lapse confocal microscopy, micro-irradiation by UV laser (355 nm) and GFP technology to study the dynamics and function of the BMI1 protein. We observed that BMI1 was recruited to UV-damaged chromatin simultaneously with decreased lysine acetylation, followed by the recruitment of heterochromatin protein HP1β to micro-irradiated regions. Pronounced recruitment of BMI1 was rapid, with half-time τ = 15 sec; thus, BMI1 is likely involved in the initiation step leading to the recognition of UV-damaged sites. Histone hyperacetylation, stimulated by HDAC inhibitor TSA, suppression of transcription by actinomycin D, and ATP-depletion prevented increased accumulation of BMI1 to γH2AX-positive irradiated chromatin. Moreover, BMI1 had slight ability to recognize spontaneously occurring DNA breaks caused by other pathophysiological processes. Taken together, our data indicate that the dynamics of recognition of UV-damaged chromatin, and the nuclear arrangement of BMI1 protein can be influenced by acetylation and occur as an early event prior to the recruitment of HPβ to UV-irradiated chromatin.
authors: Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic.
authors: Gabriela
authors: G
authors: Sustáčková
authors: Stanislav
authors: S
authors: Kozubek
authors: Lenka
authors: L
authors: Stixová
authors: Soňa
authors: S
authors: Legartová
authors: Pavel
authors: P
authors: Matula
authors: Darya
authors: D
authors: Orlova
authors: Eva
authors: E
authors: Bártová
mesh_terms: D016475:3T3 Cells; D000107:Acetylation; D000818:Animals; D002460:Cell Line; D002843:Chromatin / Q000378:metabolism* / Q000528:radiation effects*; D000090266:Chromobox Protein Homolog 5; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism; D004249:DNA Damage; D036681:Fluorescence Recovery After Photobleaching; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D056572:Histone Deacetylase Inhibitors / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D006801:Humans; D006877:Hydroxamic Acids / Q000378:metabolism; D051379:Mice; D018613:Microscopy, Confocal / Q000379:methods; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D063150:Polycomb Repressive Complex 1; D063146:Polycomb-Group Proteins; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D059008:Time-Lapse Imaging; D014466:Ultraviolet Rays
chemical_list: C069077:BMI1 protein, human; C000715593:CBX1 protein, human; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D056572:Histone Deacetylase Inhibitors; D006657:Histones; D006877:Hydroxamic Acids; D009687:Nuclear Proteins; D063146:Polycomb-Group Proteins; D011518:Proto-Oncogene Proteins; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D000090266:Chromobox Protein Homolog 5; D049452:Green Fluorescent Proteins; C012589:trichostatin A; D063150:Polycomb Repressive Complex 1