title: Getting it done at the ends: Pif1 family DNA helicases and telomeres.
abstract: It is widely appreciated that the ends of linear DNA molecules cannot be fully replicated by the conventional replication apparatus. Less well known is that semi-conservative replication of telomeric DNA also presents problems for DNA replication. These problems likely arise from the atypical chromatin structure of telomeres, the GC-richness of telomeric DNA that makes it prone to forming DNA secondary structures, and from RNA-DNA hybrids, formed by transcripts of one or both DNA strands. Given the different aspects of telomeres that complicate their replication, it is not surprising that multiple DNA helicases promote replication of telomeric DNA. This review focuses on one such class of DNA helicases, the Pif1 family of 5'-3' DNA helicases. In budding and fission yeasts, Pif1 family helicases impact both telomerase-mediated and semi-conservative replication of telomeric DNA as well as recombination-mediated telomere lengthening.
authors.affiliation: Department of Molecular Biology, Princeton University, Princeton, NJ 08544 USA.
authors.forename: Carly L
authors.initials: CL
authors.lastname: Geronimo
authors.affiliation: Department of Molecular Biology, Princeton University, Princeton, NJ 08544 USA. Electronic address: vzakian@princeton.edu.
authors.forename: Virginia A
authors.initials: VA
authors.lastname: Zakian
mesh_terms: D020029:Base Pairing; D002843:Chromatin / Q000378:metabolism / Q000648:ultrastructure; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D004261:DNA Replication; D006801:Humans; D005810:Multigene Family; D009690:Nucleic Acid Conformation; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism; D016615:Telomere / Q000378:metabolism* / Q000648:ultrastructure; D059505:Telomere Homeostasis
chemical_list: D002843:Chromatin; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; D004247:DNA; C085463:PIF1 protein, S cerevisiae; C459081:Rrm3 protein, S cerevisiae; D004265:DNA Helicases
keywords: ALT; Break induced replication; DNA replication; Helicase; Pif1; TERRA; Telomerase; Telomere