RT Journal Article
T1 The ribotoxin α-sarcin can cleave the sarcin/ricin loop on late 60S pre-ribosomes.
A1 Olombrada, Miriam
A1 Peña, Cohue
A1 Rodríguez-Galán, Olga
A1 Klingauf-Nerurkar, Purnima
A1 Portugal-Calisto, Daniela
A1 Oborská-Oplová, Michaela
A1 Altvater, Martin
A1 Gavilanes, José G
A1 Martínez-Del-Pozo, Álvaro
A1 de la Cruz, Jesús
A1 García-Ortega, Lucía
A1 Panse, Vikram Govind
AB The ribotoxin α-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 α-sarcin targets the SRL only in mature 60S subunits remains unresolved. Here, we show that, in yeast, α-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 α-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 α-sarcin cleaved SRL might be assessed only during translation.
YR 2020
FD 2020
LK http://hdl.handle.net/10668/15496
UL http://hdl.handle.net/10668/15496
LA en
DS RISalud
RD Apr 6, 2025