title: Position-dependent termination and widespread obligatory frameshifting in Euplotes translation.
abstract: The ribosome can change its reading frame during translation in a process known as programmed ribosomal frameshifting. These rare events are supported by complex mRNA signals. However, we found that the ciliates Euplotes crassus and Euplotes focardii exhibit widespread frameshifting at stop codons. 47 different codons preceding stop signals resulted in either +1 or +2 frameshifts, and +1 frameshifting at AAA was the most frequent. The frameshifts showed unusual plasticity and rapid evolution, and had little influence on translation rates. The proximity of a stop codon to the 3' mRNA end, rather than its occurrence or sequence context, appeared to designate termination. Thus, a 'stop codon' is not a sufficient signal for translation termination, and the default function of stop codons in Euplotes is frameshifting, whereas termination is specific to certain mRNA positions and probably requires additional factors.
authors.affiliation: Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusets, USA.
authors.forename: Alexei V
authors.initials: AV
authors.lastname: Lobanov
authors.affiliation: School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Heaphy
authors.affiliation: Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusets, USA.
authors.forename: Anton A
authors.initials: AA
authors.lastname: Turanov
authors.affiliation: Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusets, USA.
authors.forename: Maxim V
authors.initials: MV
authors.lastname: Gerashchenko
authors.affiliation: School of Biosciences and Biotechnology, University of Camerino, Camerino, Italy.
authors.forename: Sandra
authors.initials: S
authors.lastname: Pucciarelli
authors.affiliation: School of Biosciences and Biotechnology, University of Camerino, Camerino, Italy.
authors.forename: Raghul R
authors.initials: RR
authors.lastname: Devaraj
authors.affiliation: Pacific Northwest National Laboratory, Richland, Washington, USA.
authors.forename: Fang
authors.initials: F
authors.lastname: Xie
authors.affiliation: Pacific Northwest National Laboratory, Richland, Washington, USA.
authors.forename: Vladislav A
authors.initials: VA
authors.lastname: Petyuk
authors.affiliation: Pacific Northwest National Laboratory, Richland, Washington, USA.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Smith
authors.affiliation: Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, Connecticut, USA.
authors.forename: Lawrence A
authors.initials: LA
authors.lastname: Klobutcher
authors.affiliation: School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland.
authors.forename: John F
authors.initials: JF
authors.lastname: Atkins
authors.affiliation: School of Biosciences and Biotechnology, University of Camerino, Camerino, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Miceli
authors.affiliation: Molecular Biology of Selenium Section, Mouse Cancer Genetics Program, Center for Cancer Research, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Dolph L
authors.initials: DL
authors.lastname: Hatfield
authors.affiliation: School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland.
authors.forename: Pavel V
authors.initials: PV
authors.lastname: Baranov
authors.affiliation: Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusets, USA.
authors.forename: Vadim N
authors.initials: VN
authors.lastname: Gladyshev
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D016812:Euplotes / Q000235:genetics* / Q000378:metabolism; D016368:Frameshift Mutation; D010443:Peptide Chain Termination, Translational; D020543:Proteome / Q000235:genetics / Q000378:metabolism; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism; D059467:Transcriptome
chemical_list: D020543:Proteome; D015800:Protozoan Proteins