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oai:docta.ucm.es:20.500.14352/65742024-09-23T17:43:26Zcom_20.500.14352_14col_20.500.14352_15

Olombrada, Miriam Peña, Cohue Rodríguez Galán, Olga Klingauf Nerurkar, Purnima Portugal Calisto, Daniela Oborská Oplová, Michaela Altvater, Martin Gavilanes, José G. Martínez Del Pozo, Álvaro Cruz, Jesús de la García Ortega, Lucía Govind Panse, Vikram 2023-06-16T15:23:54Z 2023-06-16T15:23:54Z 2020 1362-4962 doi.org/10.1093/nar/gkaa315 https://hdl.handle.net/20.500.14352/6574 https://doi.org/10.1093/nar/gkaa315 https://academic.oup.com/nar/article/48/11/6210/5828919 The ribotoxin -sarcin belongs to a family of ribonucleases that cleave the sarcin/ricin loop (SRL), a critical functional rRNA element within the large ribosomal subunit (60S), thereby abolishing translation. Whether -sarcin targets the SRL only in mature 60S subunits remains unresolved. Here, we show that, in yeast, -sarcin can cleave SRLs within late 60S pre-ribosomes containing mature 25S rRNA but not nucleolar/nuclear 60S pre-ribosomes containing 27S pre-rRNA in vivo. Conditional expression of -sarcin is lethal, but does not impede early pre-rRNA processing, nuclear export and the cytoplasmic maturation of 60S pre-ribosomes. Thus, SRL-cleaved containing late 60S pre-ribosomes seem to escape cytoplasmic proofreading steps. Polysome analyses revealed that SRL-cleaved 60S ribosomal subunits form 80S initiation complexes, but fail to progress to the step of translation elongation. We suggest that the functional integrity of a -sarcin cleaved SRL might be assessed only during translation. eng https://creativecommons.org/licenses/by-nc/3.0/es/ open access Atribución-NoComercial 3.0 España The ribotoxin -sarcin can cleave the sarcin/ricin loop on late 60S pre-ribosomes journal article