Investigating splicing in two disparate organisms: a highly reduced spliceosome in Cyandioschyzon Merolae and additional functionality in Saccharomyces Cerevisiae's PRP24

Abstract

Splicing, the removal of non-protein coding introns from pre-mRNA, is a critical step in eukaryotic gene expression that is facilitated by a large, dynamic ribonucleoprotein complex known as the spliceosome. The spliceosome is composed of five subcomponents of small nuclear ribonucleoprotein particles consisting of a snRNA and their associated proteins; these "snRNPs" are referred to as U1, U2, U4, U5, and U6. Recently, the red alga Cyanidioschyzon merolae was found to be lacking the U1 snRNA, raising questions of whether U1 proteins are also absent and to what extent the rest of the spliceosome is reduced.To address this, I computationally searched for known splicing proteins in C. merolae. In doing so, I found no U1 proteins and a highly reduced spliceosome consisting of 69 splicing proteins in the organism. Additionally, I performed several investigations into Prp24 functionality and I submit that, in addition to U6 binding through electropositive residues in Prp24's second RNA recognition motif, there exists a secondary function based on the presence of cold-sensitive phenotypes in the region.iii