The proteome of the eukaryotic pre-mRNA splicing cycle
Eukaryotic pre-mRNA splicing, i.e. removal of intron and ligation of exons is catalyzed by a highly dynamic macromolecular machinery, the spliceosome. Alternatively spliced pre-mRNAs are a major source for the protein diversity in higher eukaryotes furthermore, abberant alternative splicing is a source for several diseases. In the process of splicing the spliceosome assembles stepwise on the pre-mRNA and then passes through different functional stages until the mature mRNA is relaesed. In collaboration with the group of Reinhard Lührmann at the Max Planck Institute for Biophysical Chemistry we are analyzing the protein components of the single functional stages of the spliceosome, compare the relative quantities of protein factors in their different stages and decipher their phosphorylation states in the different stages by iTRAQ and SILAC labelling technologies and various phosphopeptide enrichment stragtegies, respectively.