Interactions between Splicing Factors and the small nuclear RNA (snRNA) U2 During Spliceosome Assembly in Saccharomyces cerevisiae.

• Grant number: 24/03395-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: August 01, 2024
• End date: February 28, 2026
• Field of knowledge: Biological Sciences - Biochemistry - Molecular Biology
• Principal Investigator: Carla Columbano de Oliveira
• Grantee: Emerson Fernando Balan
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 20/00901-1 - Posttranscriptional control of gene expression: pre-rRNA processing, mRNA degradation, splicing and snoRNP assembly in Saccharomyces cerevisiae, AP.TEM

Abstract

The small nuclear RNA (snRNA) U2 is an essential component of the spliceosome that interacts directly with conserved sequences in pre-mRNA during splicing. The role of U2 snRNA extends from the assembly of the pre-spliceosome, through its activation and catalysis, to the disassembling of the complex and involves various changes in its structure. The formation of the small nuclear ribonucleoprotein (snRNP) U2, the particle that effectively binds to the spliceosome, requires the association of different sub-complexes with snRNA-specific modules, transient proteins and RNA-dependent ATPases whose mechanism of action is not fully known. In addition to being evolutionarily conserved, most of these factors are essential for the pairing between snRNA U2 and the branch site (BS) in the pre-mRNA. Although the composition and structure of the active form of U2 snRNP have already been described, the formation of this ribonucleoprotein remains a poorly explored process. In addition, the function of various components of U2 snRNP during the spliceosome assembly is still insufficiently understood. This project aims to define the composition of stalled intermediate forms of U2 snRNP using thermo-sensitive mutants to identify and characterize auxiliary factors involved in its formation.