Unique domain appended to vertebrate tRNA synthetase is essential for vascular development.
Xu, X., Shi, Y., Zhang, H.M., Swindell, E.C., Marshall, A.G., Guo, M., Kishi, S., Yang, X.L.(2012) Nat Commun 3: 681-681
- PubMed: 22353712 
- DOI: https://doi.org/10.1038/ncomms1686
- Primary Citation of Related Structures:  
3VBB - PubMed Abstract: 
New domains were progressively added to cytoplasmic aminoacyl transfer RNA (tRNA) synthetases during evolution. One example is the UNE-S domain, appended to seryl-tRNA synthetase (SerRS) in species that developed closed circulatory systems. Here we show using solution and crystal structure analyses and in vitro and in vivo functional studies that UNE-S harbours a robust nuclear localization signal (NLS) directing SerRS to the nucleus where it attenuates vascular endothelial growth factor A expression. We also show that SerRS mutants previously linked to vasculature abnormalities either deleted the NLS or have the NLS sequestered in an alternative conformation. A structure-based second-site mutation, designed to release the sequestered NLS, restored normal vasculature. Thus, the essential function of SerRS in vascular development depends on UNE-S. These results are the first to show an essential role for a tRNA synthetase-associated appended domain at the organism level, and suggest that acquisition of UNE-S has a role in the establishment of the closed circulatory systems of vertebrates.
Organizational Affiliation: 
Department of Chemical Physiology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.