Dynamic Protein-Protein Interaction Wiring of the Human Spliceosome

• DOI: 10.1016/j.molcel.2011.12.034
• Publication Date: 2012-02-23T19:40:54Z
• Authors: Anna Hegele; Atanas Kamburov; Arndt Grossmann; Chrysovalantis So...; Sylvia Wowro; Mareike Weimann; Cindy L. Will; Vlad Pena; Reinhard Lührmann; Ulrich Stelzl
• Keywords: Proteomics; 0303 health sciences; RNA Splicing; RNA-Binding Proteins; Cell Biology; Ribonucleoproteins, Small Nuclear; Binding, Competitive; DEAD-box RNA Helicases; 03 medical and health sciences; RNA Precursors; Spliceosomes; Cluster Analysis; Humans; Protein Interaction Domains and Motifs; Protein Interaction Maps; RNA Splicing Factors; RNA, Messenger; Carrier Proteins; Molecular Biology; RNA Helicases

More than 200 proteins copurify with spliceosomes, the compositionally dynamic RNPs catalyzing pre-mRNA splicing. To better understand protein - protein interactions governing splicing, we systematically investigated interactions between human spliceosomal proteins. A comprehensive Y2H interaction matrix screen generated a protein interaction map comprising 632 interactions between 196 proteins. Among these, 242 interactions were found between spliceosomal core proteins and largely validated by coimmunoprecipitation. To reveal dynamic changes in protein interactions, we integrated spliceosomal complex purification information with our interaction data and performed link clustering. These data, together with interaction competition experiments, suggest that during step 1 of splicing, hPRP8 interactions with SF3b proteins are replaced by hSLU7, positioning this second step factor close to the active site, and that the DEAH-box helicases hPRP2 and hPRP16 cooperate through ordered interactions with GPKOW. Our data provide extensive information about the spliceosomal protein interaction network and its dynamics.