Aminoacyl-tRNA synthetase dependent angiogenesis revealed by a bioengineered macrolide inhibitor.
Aminoacyl-tRNA synthetases (AARSs) catalyze an early step in protein synthesis, but also regulate diverse physiological processes in animal cells. These include angiogenesis, and human threonyl-tRNA synthetase (TARS) represents a potent pro-angiogenic AARS. Angiogenesis stimulation can be blocked by the macrolide antibiotic borrelidin (BN), which exhibits a broad spectrum toxicity that has discouraged deeper investigation. Recently, a less toxic variant (BC194) was identified that potently inhibits angiogenesis. Employing biochemical, cell biological, and biophysical approaches, we demonstrate that the toxicity of BN and its derivatives is linked to its competition with the threonine substrate at the molecular level, which stimulates amino acid starvation and apoptosis. By separating toxicity from the inhibition of angiogenesis, a direct role for TARS in vascular development in the zebrafish could be demonstrated. Bioengineered natural products are thus useful tools in unmasking the cryptic functions of conventional enzymes in the regulation of complex processes in higher metazoans.
Department of Biochemistry, University of Vermont.
Adam C
AC
Mirando
Department of Cancer Biology, The Scripps Research Institute, Scripps Florida.
Pengfei
P
Fang
Department of Pharmacology, University of Vermont.
Tamara F
TF
Williams
Department of Pharmacology, University of Vermont.
Linda C
LC
Baldor
Department of Pharmacology, University of Vermont.
Alan K
AK
Howe
Department of Biology, University of Vermont.
Alicia M
AM
Ebert
Isomerase Therapeutics Ltd, Science Village, Chesterford Research Park, Cambridge CB10 1XL, UK.
Barrie
B
Wilkinson
Department of Pharmacology, University of Vermont.
Karen M
KM
Lounsbury
Department of Cancer Biology, The Scripps Research Institute, Scripps Florida.
Min
M
Guo
Department of Biochemistry, University of Vermont.
Christopher S
CS
Francklyn
D000604:Amino Acyl-tRNA Synthetases / Q000378:metabolism*; D020533:Angiogenesis Inhibitors / Q000008:administration & dosage* / Q000737:chemistry; D042501:Angiogenic Proteins / Q000378:metabolism*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D018942:Macrolides / Q000037:antagonists & inhibitors*; D018919:Neovascularization, Physiologic / Q000187:drug effects* / Q000502:physiology*; D015027:Zebrafish
D020533:Angiogenesis Inhibitors; D042501:Angiogenic Proteins; D018942:Macrolides; D000604:Amino Acyl-tRNA Synthetases