title: Molecular dynamics of de novo telomere heterochromatin formation in budding yeast.
abstract: In the budding yeast Saccharomyces cerevisiae, heterochromatin structure is found at three chromosome regions, which are homothallic mating-type loci, rDNA regions and telomeres. To address how telomere heterochromatin is assembled under physiological conditions, we employed a de novo telomere addition system, and analyzed the dynamic chromatin changes of the TRP1 reporter gene during telomere elongation. We found that integrating a 255-bp, but not an 81-bp telomeric sequence near the TRP1 promoter could trigger Sir2 recruitment, active chromatin mark(s)' removal, chromatin compaction and TRP1 gene silencing, indicating that the length of the telomeric sequence inserted in the internal region of a chromosome is critical for determining the chromatin state at the proximal region. Interestingly, Rif1 but not Rif2 or yKu is indispensable for the formation of intra-chromosomal silent chromatin initiated by telomeric sequence. When an internal short telomeric sequence (e.g., 81 bp) gets exposed to become a de novo telomere, the herterochromatin features, such as Sir recruitment, active chromatin mark(s)' removal and chromatin compaction, are detected within a few hours before the de novo telomere reaches a stable length. Our results recapitulate the molecular dynamics and reveal a coherent picture of telomere heterochromatin formation.
authors.affiliation: The State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China.
authors.forename: Yi-Min
authors.initials: YM
authors.lastname: Duan
authors.affiliation: The State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China.
authors.forename: Bo-O
authors.initials: BO
authors.lastname: Zhou
authors.affiliation: The State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Peng
authors.affiliation: The State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China.
authors.forename: Xia-Jing
authors.initials: XJ
authors.lastname: Tong
authors.affiliation: The State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China.
authors.forename: Qiong-Di
authors.initials: QD
authors.lastname: Zhang
authors.affiliation: The State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China; School of Life Science and Technology, Shanghai Tech University, 100 Haike Road, Shanghai 200031, China. Electronic address: jqzhou@sibcb.ac.cn.
authors.forename: Jin-Qiu
authors.initials: JQ
authors.lastname: Zhou
mesh_terms: D019747:Aldose-Ketose Isomerases / Q000172:deficiency / Q000235:genetics; D001483:Base Sequence; D020868:Gene Silencing; D056426:Genetic Loci / Q000235:genetics; D006570:Heterochromatin / Q000235:genetics*; D012097:Repressor Proteins / Q000172:deficiency / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D019098:Telomerase / Q000378:metabolism; D016615:Telomere / Q000235:genetics*; D034501:Telomere-Binding Proteins / Q000172:deficiency / Q000235:genetics
chemical_list: D006570:Heterochromatin; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D034501:Telomere-Binding Proteins; C074461:RIF1 protein, S cerevisiae; D019098:Telomerase; D019747:Aldose-Ketose Isomerases; C490353:TRP1 protein, S cerevisiae
keywords: Heterochromatin; Nucleosome positioning; Sir; Telomere; yKu