The Essential Nucleolar Yeast Protein Nop8p Controls the Exosome Function during 60S Ribosomal Subunit Maturation

Autor(es)

Santos, Marcia C. T. ^[1] ; Goldfeder, Mauricio B. ^[1] ; Zanchin, Nilson I. T. ^{[2, 3]} ; Oliveira, Carla C. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Biochem, Inst Chem, Sao Paulo - Brazil

^[2] Univ Estadual Campinas, Ctr Biol Mol & Engn Genet, Sao Paulo - Brazil

^[3] Univ Estadual Campinas, Fac Ciencias Aplicadas, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: PLoS One; v. 6, n. 6 JUN 29 2011.
• Citações Web of Science: 1

Resumo

The yeast nucleolar protein Nop8p has previously been shown to interact with Nip7p and to be required for 60S ribosomal subunit formation. Although depletion of Nop8p in yeast cells leads to premature degradation of rRNAs, the biochemical mechanism responsible for this phenotype is still not known. In this work, we show that the Nop8p amino-terminal region mediates interaction with the 5.8S rRNA, while its carboxyl-terminal portion interacts with Nip7p and can partially complement the growth defect of the conditional mutant strain Dnop8/GAL::NOP8. Interestingly, Nop8p mediates association of Nip7p to pre-ribosomal particles. Nop8p also interacts with the exosome subunit Rrp6p and inhibits the complex activity in vitro, suggesting that the decrease in 60S ribosomal subunit levels detected upon depletion of Nop8p may result from degradation of pre-rRNAs by the exosome. These results strongly indicate that Nop8p may control the exosome function during pre-rRNA processing. (AU)

• Processo FAPESP: 09/52826-4 - Caracterizacao funcional das proteinas de saccharomyces cerevisiae, nop17p e cwc24p, que estao envolvidas em processamento de rna
• Beneficiário: Carla Columbano de Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Regular