Characterization of Saccharomyces cerevisiae Nop17p, a novel Nop58p-interacting pre-rRNA processing

Autor(es)

Gonzales, Fernando A. ; Zanchin, Nilson I. T. ; Luz, Juliana Silva da ^[3] ; Oliveira, Carla Columbano de

• Tipo de documento: Artigo Científico
• Fonte: Journal of Molecular Biology; v. 346, n. 2, p. 437-455, Feb. 2005.
• Área do conhecimento: Ciências Biológicas - Bioquímica
• Assunto(s): Proteínas Fenótipo

Resumo

In eukaryotes, pre-rRNA processing depends on cis-acting elements and on a large number of non-ribosomal trans-acting factors, including endonucleases and exonucleases, RNA helicases, rRNA modifying enzymes and components of snoRNPs. The exosome is a conserved eukaryotic protein complex containing multiple 3'-5' exonucleases, which has been implicated in pre-rRNA, snoRNA and snRNA processing, as well as in mRNA. degradation. In order to identify new proteins involved in rRNA processing, we have screened a yeast two-hybrid cDNA library, to isolate proteins interacting with the exosome subunit Rrp43p. In this screen, a novel nucleolar protein, Nop17p, was identified which also interacts with the box C/D snoRNP protein Nop58p. The NOP17 gene is not essential for cell viability but its deletion causes a temperature-sensitive phenotype. Pre-rRNA processing analyses revealed that rRNA formation is affected in the Deltanop17 strain subjected to the non-permissive temperature, although it is not blocked completely. In addition, primer extension analyses of RNA isolated from Nop17p-depleted cells subjected to the non-permissive temperature indicates that the pre-rRNA is undergoing different modification or degradation processes in these cells as compared to the parental strain. Nop17p was recently described in the same complex as Nop58p and, interestingly, its depletion leads to mislocalization of Nop1p, Nop56p, Nop58p and Snu13p, which are the core proteins of the box C/D ribonucleoprotein (snoRNP), indicating that Nop17p function is required either for nucleolar retention or for the proper assembly of the box C/D snoRNP. (AU)

• Processo FAPESP: 00/02788-4 - Determinação da estrutura tridimensional das proteínas TRIP-1 e INT6 e caracterização da função da INT6 no controle da proliferação celular e na iniciação da tradução
• Beneficiário: Nilson Ivo Tonin Zanchin
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 01/05469-0 - Caracterizacao do papel de proteinas que interegem com o exossomo no processamento de rna em sacchararomyces cerevisiae.
• Beneficiário: Carla Columbano de Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Regular