| Structural highlights
Function
[SYWC_HUMAN] Isoform 1, isoform 2 and T1-TrpRS have aminoacylation activity while T2-TrpRS lacks it. Isoform 2, T1-TrpRS and T2-TrpRS possess angiostatic activity whereas isoform 1 lacks it. T2-TrpRS inhibits fluid shear stress-activated responses of endothelial cells. Regulates ERK, Akt, and eNOS activation pathways that are associated with angiogenesis, cytoskeletal reorganization and shear stress-responsive gene expression.[1] [2] [3] [4]
Publication Abstract from PubMed
Tryptophanyl-tRNA synthetase (TrpRS) in vertebrates contains a N-terminal extension in front of the catalytic core. Proteolytic removal of the N-terminal 93 amino acids gives rise to T2-TrpRS, which has potent anti-angiogenic activity mediated through its extracellular interaction with VE-cadherin. Zinc has been shown to have anti-angiogenic effects and can bind to human TrpRS. However, the connection between zinc and the anti-angiogenic function of TrpRS has not been explored. Here we report that zinc binding can induce structural relaxation in human TrpRS to facilitate the proteolytic generation of a T2-TrpRS-like fragment. The zinc-binding site is likely to be contained within T2-TrpRS, and the zinc-bound conformation of T2-TrpRS is mimicked by mutation H130R. We determined the crystal structure of H130R T2-TrpRS at 2.8 A resolution, which reveals drastically different conformation from that of wild-type (WT) T2-TrpRS. The conformational change creates larger binding surfaces for VE-cadherin as suggested by molecular dynamic simulations. Surface plasmon resonance analysis indicates more than 50-fold increase in binding affinity of H130R T2-TrpRS for VE-cadherin, compared to WT T2-TrpRS. The enhanced interaction is also confirmed by a cell-based binding analysis. These results suggest that zinc plays an important role in activating TrpRS for angiogenesis regulation.
An alternative conformation of human TrpRS suggests a role of zinc in activating non-enzymatic function.,Xu X, Zhou H, Zhou Q, Hong F, Vo MN, Niu W, Wang Z, Xiong X, Nakamura K, Wakasugi K, Schimmel P, Yang XL RNA Biol. 2017 Sep 14:1-10. doi: 10.1080/15476286.2017.1377868. PMID:28910573[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Wakasugi K, Slike BM, Hood J, Otani A, Ewalt KL, Friedlander M, Cheresh DA, Schimmel P. A human aminoacyl-tRNA synthetase as a regulator of angiogenesis. Proc Natl Acad Sci U S A. 2002 Jan 8;99(1):173-7. Epub 2002 Jan 2. PMID:11773626 doi:10.1073/pnas.012602099
- ↑ Bange FC, Flohr T, Buwitt U, Bottger EC. An interferon-induced protein with release factor activity is a tryptophanyl-tRNA synthetase. FEBS Lett. 1992 Mar 30;300(2):162-6. PMID:1373391
- ↑ Otani A, Slike BM, Dorrell MI, Hood J, Kinder K, Ewalt KL, Cheresh D, Schimmel P, Friedlander M. A fragment of human TrpRS as a potent antagonist of ocular angiogenesis. Proc Natl Acad Sci U S A. 2002 Jan 8;99(1):178-83. Epub 2002 Jan 2. PMID:11773625 doi:10.1073/pnas.012601899
- ↑ Tzima E, Reader JS, Irani-Tehrani M, Ewalt KL, Schwartz MA, Schimmel P. Biologically active fragment of a human tRNA synthetase inhibits fluid shear stress-activated responses of endothelial cells. Proc Natl Acad Sci U S A. 2003 Dec 9;100(25):14903-7. Epub 2003 Nov 20. PMID:14630953 doi:10.1073/pnas.2436330100
- ↑ Xu X, Zhou H, Zhou Q, Hong F, Vo MN, Niu W, Wang Z, Xiong X, Nakamura K, Wakasugi K, Schimmel P, Yang XL. An alternative conformation of human TrpRS suggests a role of zinc in activating non-enzymatic function. RNA Biol. 2017 Sep 14:1-10. doi: 10.1080/15476286.2017.1377868. PMID:28910573 doi:http://dx.doi.org/10.1080/15476286.2017.1377868
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