Shaping Spliceosome Dynamics Through Protein Arginine Methylation

Accurate removal of intervening intronic sequences from pre-mRNA is required for proper eukaryotic gene expression. This process, termed pre-mRNA splicing, is carried out by a spliceosome, a dynamic RNA-protein macromolecular machinery. Proteomic studies have shown that many spliceosomal components and associated factors harbor protein arginine methylation, a type of post-translational modification. These findings raise the question of how arginine methylation influences the process or outcome of pre-mRNA splicing. Although targeted studies have provided important molecular insights into how this modification regulates splicing protein subcellular localization, abundance, RNA/protein interactions, and snRNP biogenesis, much remains unknown, especially given the large number of methylated proteins identified that have known roles in regulating pre-mRNA splicing. In this review, we summarize current knowledge of how protein arginine methylation contributes to pre-mRNA splicing and discuss how this modification may help tune the structural and functional plasticity of the spliceosome.