tailieunhanh - Báo cáo khoa học: CpG methylation of the CENP-B box reduces human CENP-B binding

In eukaryotes, CpG methylation is an epigenetic DNA modification that is important for heterochromatin formation. Centromere protein B (CENP-B) specifically binds to the centromeric 17 base-pair CENP-B box DNA, which contains two CpG dinucleotides. In this study, we tested complex formation by the DNA-binding domain of CENP-B with methylated and unmethylated CENP-B box DNAs, and found that CENP-B preferentially binds to the unmethylated CENP-B box DNA. | iFEBS Journal CpG methylation of the CENP-B box reduces human CENP-B binding Yoshinori Tanaka1 2 Hitoshi Kurumizaka1 3 and Shigeyuki Yokoyama1 2 4 1 Protein Research Group RIKEN Genomic Sciences Center Suehiro-cho Tsurumi Yokohama Japan 2 Department of Biophysics and Biochemistry Graduate Schoolof Science University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo Japan 3 Waseda University Schoolof Science and Engineering 3-4-1 Okubo Shinjuku-ku Tokyo Japan 4 RIKEN Harima Institute at Spring-8 1-1-1 Kohto Mikazuki-cho Sayo Hyogo Japan Keywords CENP-B centromere DNA methylation chromatin heterochromatin Correspondence H. Kurumizaka Waseda University Schoolof Science and Engineering 3-4-1 Okubo Shinjuku-ku Tokyo 169-8555 Japan Fax 81 3 5292 9211 Tel 81 3 5286 8189 E-mail kurumizaka@ S. Yokoyama Protein Research Group RIKEN Genomic Sciences Center 1-7-22 Suehiro-cho Tsurumi Yokohama 230-0045 Japan Fax 81 45 503 9195 Tel 81 45 503 9196 E-mail yokoyama@ In eukaryotes CpG methylation is an epigenetic DNA modification that is important for heterochromatin formation. Centromere protein B CENP-B specifically binds to the centromeric 17 base-pair CENP-B box DNA which contains two CpG dinucleotides. In this study we tested complex formation by the DNA-binding domain of CENP-B with methylated and unmethylated CENP-B box DNAs and found that CENP-B preferentially binds to the unmethylated CENP-B box DNA. Competition analyses revealed that the affinity of CENP-B for the CENP-B box DNA is reduced nearly to the level of nonspecific DNA binding by CpG methylation. Present address Toray Industries Inc. New Frontiers Research Laboratories 1111 Tebiro Kamakura Kanagawa 248-0036 Japan Received 15 September 2004 accepted 1 October 2004 doi The centromere of eukaryotic chromosomes plays an essential role in the proper segregation of chromosomes at mitosis and meiosis and has a special heterochromatin structure which is composed of .