Co-evolution of spliceosomal disassembly interologs: crowning J-protein component with moonlighting RNA-binding activity
- 197 Downloads
Spliceosome disassembly is catalyzed by the NineTeen-related (NTR) complex, which is constituted by several proteins, including Cwc23, Ntr1, and Ppr43. Cwc23 is an essential J-protein in Saccharomyces cerevisiae that recruits Ntr1, an NTC-related G-patch protein, to the spliceosome. Ntr1 interacts with Prp43, a DExD/H box RNA helicase protein, which facilitates the disassembly of spliceosomal intermediates. The interaction between Ntr1 and Prp43 is conserved and crucial for the disassembly process. However, the J-protein component of this complex is not studied in other eukaryotes. In silico analysis supported by results of yeast complementation and two-hybrid studies suggests that while Prp43 is highly conserved, both Ntr1 and Cwc23 are co-evolving components of the disassembly triad. The J-domain of Cwc23, which is otherwise dispensable for its function, is highly conserved, whereas the functionally critical C-terminus has significantly diverged in Cwc23 orthologs. Some eukaryotic orthologs of Cwc23 contain a distinct RNA recognition motif at their C-terminus and are able to bind RNA in vitro. Based on the results presented in this study, we propose that RNA-binding activity in some eukaryotic orthologs of Cwc23 might provide additional functional diversity or robustness to the J-protein/Hsp70 machine in spliceosomal remodelling processes.
KeywordsJ-proteins S. cerevisiae K. lactis S. pombe Spliceosome Co-evolution RRM
We would like to thank Prof. Elizabeth Craig (University of Wisconsin–Madison), and Prof. R.S. Tomar (Indian Institute of Science Education and Research, Bhopal) for yeast strains, plasmids, and antibodies. We thank C.S. lab members for critical comments. We thank the reviewers for their valuable suggestions which really helped in improving this manuscript. S.R. and A.K.V. thank the Indian Ministry of Human Resource Development for a Graduate Aptitude Test in Engineering fellowship; K.Y. and Y.T. thank Council of Scientific and Industrial Research, Government of India, for fellowship. This work was supported by project grants from the Department of Biotechnology (BT/PR12149/BRB/10/1348/2014), Government of India to C.S. We thank IISER Bhopal for intramural funds and the Central Instrumentation Facility.
- Hendrick JP, Hartl FU (1993) Molecular chaperone functions of heat-shock proteins. Annu Rev Biochem 62:349–384. https://doi.org/10.1146/annurev.bi.62.070193.002025 CrossRefGoogle Scholar
- Kim YE, Hipp MS, Bracher A, Hayer-Hartl M, Hartl FU (2013) Molecular chaperone functions in protein folding and proteostasis. Annu Rev Biochem 82:323–355. https://doi.org/10.1146/annurev-biochem-060208-092442 CrossRefGoogle Scholar
- Sicard H, Faubladier M, Noaillac-Depeyre J, Leger-Silvestre I, Gas N, Caizergues-Ferrer M (1998) The role of the Schizosaccharomyces pombe gar2 protein in nucleolar structure and function depends on the concerted action of its highly charged N terminus and its RNA-binding domains. Mol Biol Cell 9:2011–2023CrossRefGoogle Scholar
- Tizon B, Rodriguez-Torres AM, Cerdan ME (1999) Disruption of six novel Saccharomyces cerevisiae genes reveals that YGL129c is necessary for growth in non-fermentable carbon sources, YGL128c for growth at low or high temperatures and YGL125w is implicated in the biosynthesis of methionine. Yeast 15:145–154. https://doi.org/10.1002/(SICI)1097-0061(19990130)15:2%3C145::AID-YEA346%3E3.0.CO;2-J CrossRefGoogle Scholar