The role of Rrp43p on assembly and stabilization of Saccharomyces cerevisiae exosome complex

Author(s)

Germano Alves Paiva

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Conjunto das Químicas (IQ e FCF) (CQ/DBDCQ)
• Defense date: 2012-04-16

Examining board members

Carla Columbano de Oliveira; Mário Henrique de Barros; Sandro Roberto Marana

• Advisor: Carla Columbano de Oliveira

Abstract

The exosome is a protein complex comprised of up to eleven subunits (Rrp4p, Rrp6p, Rrp40p, Rrp41p, Rrp42p, Rrp43p, Rrp44p, Rrp45p, Rrp46p, Csl4p and Mtr3p) that has 3`→5` exoribonucleolytic activity and is involved in degradation and processing pathways of several kinds of RNA in eukaryotes. This complex has also been identified in several organisms, such as yeast, insects, plants, humans and also many species of archaea. Despite the overall structure conservation of the complex throughout evolution and eight of the eukaryotic exosome subunits displaying RNase domains, only two proteins, Rrp6p and Rrp44p have catalytic activity. Although the exosome has been shown to be involved in many different aspects of RNA metabolism, the role that each subunit plays in the activity of the complex has not yet been determined. In this work we used of TAP-purified exosome complexes to study the effect of Rrp43p mutations on the assembly and stabilization of the complex in Saccharomyces cerevisiae. Co-immunoprecipitation assays revealed that Rrp43p mutants co-purify Mtr3p and Rrp44p subunits less efficiently. Besides, Rrp43p mutants also present decreased activity, indicating that an assembly defect may affect its enzymatic activity (AU)

• FAPESP's process: 10/04412-3 - The role of Rrp43p on assembly and stabilization of Saccharomyces cerevisiase exosome complex
• Grantee: Germano Alves Paiva
• Support Opportunities: Scholarships in Brazil - Master