Identification of archaeal proteins that affect the exosome function in vitro

Autor(es)

Luz, Juliana S. ^[1] ; Ramos, Celso R. R. ^{[1, 2]} ; Santos, Marcia C. T. ^[1] ; Coltri, Patricia P. ^{[3, 4, 5]} ; Palhano, Fernando L. ^[6] ; Foguel, Debora ^[6] ; Zanchin, Nilson I. T. ^[3] ; Oliveira, Carla C. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Chem, Dept Biochem, BR-05508000 Sao Paulo - Brazil

^[2] Fiocruz MS, Dept Helminthol, BR-21045900 Rio De Janeiro - Brazil

^[3] LNLS, Brazilian Synchrotron Light Lab, Ctr Struct Mol Biol, BR-13083970 Campinas, SP - Brazil

^[4] Univ Calif Santa Cruz, Dept Mol Cell & Dev Biol, Santa Cruz, CA 95064 - USA

^[5] Univ Calif Santa Cruz, Ctr Mol Biol RNA, Santa Cruz, CA 95064 - USA

^[6] Univ Fed Rio de Janeiro, CCS, Inst Med Biochem, BR-21941590 Rio De Janeiro - Brazil

• Tipo de documento: Artigo Científico
• Fonte: BMC BIOCHEMISTRY; v. 11, MAY 27 2010.
• Citações Web of Science: 10

Resumo

Background: The archaeal exosome is formed by a hexameric RNase PH ring and three RNA binding subunits and has been shown to bind and degrade RNA in vitro. Despite extensive studies on the eukaryotic exosome and on the proteins interacting with this complex, little information is yet available on the identification and function of archaeal exosome regulatory factors. Results: Here, we show that the proteins PaSBDS and PaNip7, which bind preferentially to poly-A and AU-rich RNAs, respectively, affect the Pyrococcus abyssi exosome activity in vitro. PaSBDS inhibits slightly degradation of a poly-rA substrate, while PaNip7 strongly inhibits the degradation of poly-A and poly-AU by the exosome. The exosome inhibition by PaNip7 appears to depend at least partially on its interaction with RNA, since mutants of PaNip7 that no longer bind RNA, inhibit the exosome less strongly. We also show that FITC-labeled PaNip7 associates with the exosome in the absence of substrate RNA. Conclusions: Given the high structural homology between the archaeal and eukaryotic proteins, the effect of archaeal Nip7 and SBDS on the exosome provides a model for an evolutionarily conserved exosome control mechanism. (AU)

• Processo FAPESP: 05/56493-9 - Caracterização funcional de uma nova proteína de Saccharomyces cerevisiae potencialmente envolvida em processamento de RNA
• Beneficiário: Carla Columbano de Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 07/57096-9 - Caracterização funcional de novas proteínas de Saccharomyces cerevisiae envolvidas em processamento de RNA: papel de Nop8p e kr071p na maturação do pre-60s
• Beneficiário: Carla Columbano de Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Regular