Poster abstracts
Poster number 46 submitted by Trevor Doiron
Dissecting the role of protein arginine methylation on the function of Snp1, the yeast homolog of human U1-70K
Trevor Doiron (Department of Biological Sciences, University at Buffalo), Michael C. Yu (Department of Biological Sciences, University at Buffalo)
Abstract:
Unlike mammalian systems, Saccharomyces cerevisiae expresses a single type I PRMT, Hmt1. Previous studies have shown that Hmt1 catalyzes arginine methylation on the U1 snRNP subunit, Snp1. This protein, along with its human homolog U1-70K, is involved in the association of the U1 snRNP with the 5’ splice site (SS). However, how arginine methylation affects Snp1 function remains largely unknown. In this study, we aim to dissect the functional role of specific methylation sites on Snp1 by analyzing the phenotypic consequence of arginine substitution mutants. Additionally, we use a genetic approach to investigate the effect of these mutations on the U1 snRNA association with the 5’SS. Two classes of Snp1 methylarginine substitution mutants were generated: arginine-to-lysine mutants, which preserves the amino acid charge, and arginine-to-alanine mutants. By assessing the combined effects of Snp1 methylarginine mutations and specific U1 snRNA point mutants on yeast growth phenotypes, we aim to gain insight into how Snp1 arginine methylation affects U1 association with pre-mRNA. Our findings indicate that methylation at these specific arginine sites does not significantly impact yeast growth phenotypes. However, when combined with specific U1 snRNA mutations, Snp1 methylarginine mutations do impact growth phenotype compared to either mutation alone. Current efforts are focused on uncovering the molecular basis underlying this observed interaction.
Keywords: Protein arginine methylation, Spliceosome, Snp1