title: Small angle X-ray scattering studies of CTNNBL1 dimerization and CTNNBL1/CDC5L complex.
abstract: The hPrp19/CDC5L complex is a non-snRNP spliceosome complex that plays a key role in the spliceosome activation during pre-mRNA splicing, and CTNNBL1 and CDC5L are essential components of the complex. In this study, to investigate the oligomeric state of CTNNBL1 in solution, we performed small angle X-ray scattering experiments in various concentrations of NaCl. We observed that CTNNBL1 existed as a dimer in physiological NaCl concentrations. Site-directed mutagenesis experiment of CTNNBL1 confirmed that N-terminal capping region and the first four ARM repeats are important for dimerization of the protein. We also found that the positively-charged NLS3-containing region (residues 197-235) of CDC5L bound to the negatively-charged patch of CTNNBL1 and that the CTNNBL1/CDC5L complex formed a heterotetramer consisting of one CTNNBL1 dimer and one CDC5L dimer. Moreover, reconstruction of 3D models of CTNNBL1/CDC5L complexes containing CTNNBL1 and three different truncated forms of CDC5L showed that the CDC5L(141-196) region and the CDC5L(236-377) region were positioned at the top of the N-terminal capping region and at the bottom of ARM VII of CTNNBL1, respectively.
authors.affiliation: School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University, Daehak-ro 80, Buk-ku, Daegu 702-701, Korea.
authors.forename: Jae-Woo
authors.initials: JW
authors.lastname: Ahn
authors.affiliation: Pohang Accelerator Laboratory, Pohang University of Science and Technology, Jigok-ro 80, Pohang, Kyungbuk 790-784, Korea.
authors.forename: Kyeong Sik
authors.initials: KS
authors.lastname: Jin
authors.affiliation: School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University, Daehak-ro 80, Buk-ku, Daegu 702-701, Korea.
authors.forename: Hyeoncheol Francis
authors.initials: HF
authors.lastname: Son
authors.affiliation: Department of Biology, Teachers College, Kyungpook National University, Daehak-ro 80, Buk-ku, Daegu 702-701, Korea.
authors.forename: Jeong Ho
authors.initials: JH
authors.lastname: Chang
authors.affiliation: School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University, Daehak-ro 80, Buk-ku, Daegu 702-701, Korea.
authors.forename: Kyung-Jin
authors.initials: KJ
authors.lastname: Kim
mesh_terms: D051017:Apoptosis Regulatory Proteins / Q000737:chemistry* / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008958:Models, Molecular; D009687:Nuclear Proteins / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs; D055503:Protein Multimerization; D016601:RNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D053838:Scattering, Small Angle; D012996:Solutions; D014961:X-Ray Diffraction
chemical_list: D051017:Apoptosis Regulatory Proteins; C508357:CDC5L protein, human; C479429:CTNNBL1 protein, human; D018797:Cell Cycle Proteins; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; D012996:Solutions