title: The acidic ribosomal stalk proteins are not required for the highly specific inactivation exerted by α-sarcin of the eukaryotic ribosome.
abstract: The ribosomal sarcin/ricin loop (SRL) is the target of ribosome-inactivating proteins like the N-glycosidase ricin and the fungal ribotoxin α-sarcin. The eukaryotic ribosomal stalk directly interacts with several members of the N-glycosidase family, favoring their disruption of the SRL. Here we tested this hypothesis for the ribotoxin α-sarcin. Experiments with isolated ribosomes, cell-free translation systems, and viability assays with Saccharomyces cerevisiae strains defective in acidic stalk proteins showed that the inactivation exerted by α-sarcin is independent of the composition of the ribosomal stalk. Therefore, α-sarcin, with the same ribosomal target as ricin, seems to access the SRL by a different pathway.
authors.affiliation: Departamento de Bioquímica y Biología Molecular I, Facultad de Química, Universidad Complutense , 28040 Madrid, Spain.
authors.forename: Miriam
authors.initials: M
authors.lastname: Olombrada
authors.forename: María
authors.initials: M
authors.lastname: Rodríguez-Mateos
authors.forename: Daniel
authors.initials: D
authors.lastname: Prieto
authors.forename: Jesús
authors.initials: J
authors.lastname: Pla
authors.forename: Miguel
authors.initials: M
authors.lastname: Remacha
authors.forename: Alvaro
authors.initials: A
authors.lastname: Martínez-del-Pozo
authors.forename: José G
authors.initials: JG
authors.lastname: Gavilanes
authors.forename: Juan P G
authors.initials: JP
authors.lastname: Ballesta
authors.forename: Lucía
authors.initials: L
authors.lastname: García-Ortega
mesh_terms: D004722:Endoribonucleases / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism*; D014176:Protein Biosynthesis; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism*; D012270:Ribosomes / Q000235:genetics / Q000378:metabolism*; D012276:Ricin / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D005656:Fungal Proteins; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins; C014801:alpha-sarcin; D012276:Ricin; D004722:Endoribonucleases