| Structural highlights
Function
[SYEP_HUMAN] Catalyzes the attachment of the cognate amino acid to the corresponding tRNA in a two-step reaction: the amino acid is first activated by ATP to form a covalent intermediate with AMP and is then transferred to the acceptor end of the cognate tRNA. Component of the GAIT (gamma interferon-activated inhibitor of translation) complex which mediates interferon-gamma-induced transcript-selective translation inhibition in inflammation processes. Upon interferon-gamma activation and subsequent phosphorylation dissociates from the multisynthetase complex and assembles into the GAIT complex which binds to stem loop-containing GAIT elements in the 3'-UTR of diverse inflammatory mRNAs (such as ceruplasmin) and suppresses their translation.[1] [2] [3]
Publication Abstract from PubMed
Prolyl-tRNA synthetase (PRS) is a member of the aminoacyl-tRNA synthetase family of enzymes and catalyzes the synthesis of prolyl-tRNAPro using ATP, l-proline, and tRNAPro as substrates. An ATP-dependent PRS inhibitor, halofuginone, was shown to suppress autoimmune responses, suggesting that the inhibition of PRS is a potential therapeutic approach for inflammatory diseases. Although a few PRS inhibitors have been derivatized from natural sources or substrate mimetics, small-molecule human PRS inhibitors have not been reported. In this study, we discovered a novel series of pyrazinamide PRS inhibitors from a compound library using pre-transfer editing activity of human PRS enzyme. Steady-state biochemical analysis on the inhibitory mode revealed its distinctive characteristics of inhibition with proline uncompetition and ATP competition. The binding activity of a representative compound was time-dependently potentiated by the presence of l-proline with Kd of 0.76 nM. Thermal shift assays demonstrated the stabilization of PRS in complex with l-proline and pyrazinamide PRS inhibitors. The binding mode of the PRS inhibitor to the ATP site of PRS enzyme was elucidated using the ternary complex crystal structure with l-proline. The results demonstrated the different inhibitory and binding mode of pyrazinamide PRS inhibitors from preceding halofuginone. Furthermore, the PRS inhibitor inhibited intracellular protein synthesis via a different mode than halofuginone. In conclusion, we have identified a novel drug-like PRS inhibitor with a distinctive binding mode. This inhibitor was effective in a cellular context. Thus, the series of PRS inhibitors are considered to be applicable to further development with differentiation from preceding halofuginone.
Discovery of a novel prolyl-tRNA synthetase inhibitor and elucidation of its binding mode to the ATP site in complex with l-proline.,Adachi R, Okada K, Skene R, Ogawa K, Miwa M, Tsuchinaga K, Ohkubo S, Henta T, Kawamoto T Biochem Biophys Res Commun. 2017 Jun 24;488(2):393-399. doi:, 10.1016/j.bbrc.2017.05.064. Epub 2017 May 10. PMID:28501621[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Cerini C, Kerjan P, Astier M, Gratecos D, Mirande M, Semeriva M. A component of the multisynthetase complex is a multifunctional aminoacyl-tRNA synthetase. EMBO J. 1991 Dec;10(13):4267-77. PMID:1756734
- ↑ Sampath P, Mazumder B, Seshadri V, Gerber CA, Chavatte L, Kinter M, Ting SM, Dignam JD, Kim S, Driscoll DM, Fox PL. Noncanonical function of glutamyl-prolyl-tRNA synthetase: gene-specific silencing of translation. Cell. 2004 Oct 15;119(2):195-208. PMID:15479637 doi:http://dx.doi.org/10.1016/j.cell.2004.09.030
- ↑ Arif A, Chatterjee P, Moodt RA, Fox PL. Heterotrimeric GAIT complex drives transcript-selective translation inhibition in murine macrophages. Mol Cell Biol. 2012 Dec;32(24):5046-55. doi: 10.1128/MCB.01168-12. Epub 2012 Oct , 15. PMID:23071094 doi:10.1128/MCB.01168-12
- ↑ Adachi R, Okada K, Skene R, Ogawa K, Miwa M, Tsuchinaga K, Ohkubo S, Henta T, Kawamoto T. Discovery of a novel prolyl-tRNA synthetase inhibitor and elucidation of its binding mode to the ATP site in complex with l-proline. Biochem Biophys Res Commun. 2017 Jun 24;488(2):393-399. doi:, 10.1016/j.bbrc.2017.05.064. Epub 2017 May 10. PMID:28501621 doi:http://dx.doi.org/10.1016/j.bbrc.2017.05.064
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