title: Human UBL5 protein interacts with coilin and meets the Cajal bodies.
abstract: UBL5 protein, a structural homologue of ubiquitin, was shown to be involved in pre-mRNA splicing and transcription regulation in yeast and Caenorhabditis elegans, respectively. However, role of the UBL5 human orthologue is still elusive. In our study, we observed that endogenous human UBL5 that was localized in the nucleus, partially associates with Cajal bodies (CBs), nuclear domains where spliceosomal components are assembled. Simultaneous expression of exogenous UBL5 and coilin resulted in their nuclear colocalization in HeLa cells. The ability of UBL5 to interact with coilin was proved by GST pull-down assay using coilin that was either in vitro translated or extracted from HEK293T cells. Further, our results showed that the UBL5-coilin interaction was not influenced by coilin phosphorylation. These results suggest that UBL5 could be targeted to CBs via its interaction with coilin. Relation between human UBL5 protein and CBs is in the agreement with current observations about yeast orthologue Hub1 playing important role in alternative splicing.
authors.affiliation: Department of Biochemistry and Microbiology and Center of Applied Genomics, Institute of Chemical Technology, Technická 5, 16628 Prague 6, Prague, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Svéda
authors.forename: Markéta
authors.initials: M
authors.lastname: Castorálová
authors.forename: Jan
authors.initials: J
authors.lastname: Lipov
authors.forename: Tomáš
authors.initials: T
authors.lastname: Ruml
authors.forename: Zdeněk
authors.initials: Z
authors.lastname: Knejzlík
mesh_terms: D020541:Coiled Bodies / Q000378:metabolism*; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism*; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D008856:Microscopy, Fluorescence; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D014452:Ubiquitins / Q000235:genetics / Q000378:metabolism*
chemical_list: D005136:Eye Proteins; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; C429294:UBL5 protein, human; D014452:Ubiquitins; C068921:p80-coilin; D005982:Glutathione Transferase