Two thymidine hydroxylases differentially regulate the formation of glucosylated DNA at regions flanking polymerase II polycistronic transcription units throughout the genome of Trypanosoma brucei.
Base J is a hypermodified DNA base localized primarily to telomeric regions of the genome of Trypanosoma brucei. We have previously characterized two thymidine-hydroxylases (TH), JBP1 and JBP2, which regulate J-biosynthesis. JBP2 is a chromatin re-modeling protein that induces de novo J-synthesis, allowing JBP1, a J-DNA binding protein, to stimulate additional J-synthesis. Here, we show that both JBP2 and JBP1 are capable of stimulating de novo J-synthesis. We localized the JBP1- and JBP2-stimulated J by anti-J immunoprecipitation and high-throughput sequencing. This genome-wide analysis revealed an enrichment of base J at regions flanking polymerase II polycistronic transcription units (Pol II PTUs) throughout the T. brucei genome. Chromosome-internal J deposition is primarily mediated by JBP1, whereas JBP2-stimulated J deposition at the telomeric regions. However, the maintenance of J at JBP1-specific regions is dependent on JBP2 SWI/SNF and TH activity. That similar regions of Leishmania major also contain base J highlights the functional importance of the modified base at Pol II PTUs within members of the kinetoplastid family. The regulation of J synthesis/localization by two THs and potential biological function of J in regulating kinetoplastid gene expression is discussed.
Cliffe
Laura J
LJ
Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA.
Siegel
T Nicolai
TN
Marshall
Marion
M
Cross
George A M
GA
Sabatini
Robert
R
D000818:Animals; D002460:Cell Line; D016054:DNA, Protozoan / Q000737:chemistry / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D018503:Genome, Protozoan; D005960:Glucosides / Q000096:biosynthesis*; D006657:Histones / Q000032:analysis; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D015800:Protozoan Proteins / Q000378:metabolism*; D012319:RNA Polymerase II / Q000378:metabolism; D013936:Thymidine / Q000378:metabolism; D014158:Transcription, Genetic; D014346:Trypanosoma brucei brucei / Q000201:enzymology / Q000235:genetics*; D014498:Uracil / Q000031:analogs & derivatives* / Q000096:biosynthesis
D016054:DNA, Protozoan; D004268:DNA-Binding Proteins; D005960:Glucosides; D006657:Histones; C505199:J-binding protein, Trypanosoma brucei; D015800:Protozoan Proteins; C084880:5-((glucopyranosyloxy)methyl)uracil; D014498:Uracil; D006899:Mixed Function Oxygenases; D012319:RNA Polymerase II; D013936:Thymidine