title: A conserved motif within RAP1 has diversified roles in telomere protection and regulation in different organisms.
abstract: Repressor activator protein 1 (RAP1) is the most highly conserved telomere protein. It is involved in protecting chromosome ends in fission yeast and promoting gene silencing in Saccharomyces cerevisiae, whereas it represses homology-directed recombination at telomeres in mammals. To understand how RAP1 has such diverse functions at telomeres, we solved the crystal or solution structures of the RAP1 C-terminal (RCT) domains of RAP1 from multiple organisms in complex with their respective protein-binding partners. Our analysis establishes RAP1(RCT) as an evolutionarily conserved protein-protein interaction module. In mammalian and fission yeast cells, this module interacts with TRF2 and Taz1, respectively, targeting RAP1 to chromosome ends for telomere protection. In contrast, S. cerevisiae RAP1 uses its RCT domain to recruit Sir3 to telomeres to mediate gene silencing. Together, our results show that, depending on the organism, the evolutionarily conserved RAP1 RCT motif has diverse functional roles at telomeres.
authors.affiliation: Howard Hughes Medical Institute, University of Michigan Medical School, Ann Arbor, Michigan, USA.
authors.forename: Yong
authors.initials: Y
authors.lastname: Chen
authors.forename: Rekha
authors.initials: R
authors.lastname: Rai
authors.forename: Zi-Ren
authors.initials: ZR
authors.lastname: Zhou
authors.forename: Junko
authors.initials: J
authors.lastname: Kanoh
authors.forename: Cyril
authors.initials: C
authors.lastname: Ribeyre
authors.forename: Yuting
authors.initials: Y
authors.lastname: Yang
authors.forename: Hong
authors.initials: H
authors.lastname: Zheng
authors.forename: Pascal
authors.initials: P
authors.lastname: Damay
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.forename: Hisayo
authors.initials: H
authors.lastname: Tsujii
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Hiraoka
authors.forename: David
authors.initials: D
authors.lastname: Shore
authors.forename: Hong-Yu
authors.initials: HY
authors.lastname: Hu
authors.forename: Sandy
authors.initials: S
authors.lastname: Chang
authors.forename: Ming
authors.initials: M
authors.lastname: Lei
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D002478:Cells, Cultured; D018360:Crystallography, X-Ray; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D019906:Nuclear Magnetic Resonance, Biomolecular; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D004718:Saccharomycetales / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012568:Schizosaccharomyces / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000089804:Shelterin Complex; D016615:Telomere / Q000378:metabolism*; D034501:Telomere-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D035341:Telomeric Repeat Binding Protein 2 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D000089804:Shelterin Complex; C504753:TERF2 protein, human; C440809:TERF2IP protein, human; D034501:Telomere-Binding Proteins; D035341:Telomeric Repeat Binding Protein 2