title: CTNNBL1 facilitates the association of CWC15 with CDC5L and is required to maintain the abundance of the Prp19 spliceosomal complex.
abstract: In order to catalyse the splicing of messenger RNA, multiple proteins and RNA components associate and dissociate in a dynamic highly choreographed process. The Prp19 complex is a conserved essential part of the splicing machinery thought to facilitate the conformational changes the spliceosome undergoes during catalysis. Dynamic protein interactions often involve highly disordered regions that are difficult to study by structural methods. Using amine crosslinking and hydrogen-deuterium exchange coupled to mass spectrometry, we describe the architecture of the Prp19 sub-complex that contains CTNNBL1. Deficiency in CTNNBL1 leads to delayed initiation of cell division and embryonic lethality. Here we show that in vitro CTNNBL1 enhances the association of CWC15 and CDC5L, both core Prp19 complex proteins and identify an overlap in the region of CDC5L that binds either CTNNBL1 or CWC15 suggesting the two proteins might exchange places in the complex. Furthermore, in vivo, CTNNBL1 is required to maintain normal levels of the Prp19 complex and to facilitate the interaction of CWC15 with CDC5L. Our results identify a chaperone function for CTNNBL1 within the essential Prp19 complex, a function required to maintain the integrity of the complex and to support efficient splicing.
authors.affiliation: MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK Febe.vanMaldegem@crick.ac.uk.
authors.forename: Febe
authors.identifier: http://orcid.org/0000-0002-2544-544X
authors.initials: F
authors.lastname: van Maldegem
authors.affiliation: MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Maslen
authors.affiliation: MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Johnson
authors.affiliation: MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK.
authors.forename: Anita
authors.initials: A
authors.lastname: Chandra
authors.affiliation: Department of Medicine and Cancer Biology & Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
authors.forename: Karuna
authors.initials: K
authors.lastname: Ganesh
authors.affiliation: MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Skehel
authors.affiliation: MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK car@mrc-lmb.cam.ac.uk.
authors.forename: Cristina
authors.initials: C
authors.lastname: Rada
mesh_terms: D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000378:metabolism*; D045744:Cell Line, Tumor; D057809:HEK293 Cells; D006801:Humans; D051379:Mice; D008958:Models, Molecular; D034521:Nuclear Matrix-Associated Proteins / Q000378:metabolism*; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D000072260:RNA Splicing Factors; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D017381:Spliceosomes / Q000378:metabolism
chemical_list: D051017:Apoptosis Regulatory Proteins; C508357:CDC5L protein, human; C479429:CTNNBL1 protein, human; C000602891:CWC15 protein, human; D018797:Cell Cycle Proteins; D034521:Nuclear Matrix-Associated Proteins; D009687:Nuclear Proteins; C518638:Prpf19 protein, mouse; D000072260:RNA Splicing Factors; D016601:RNA-Binding Proteins