Overexpression of mammalian phenylalanyl-tRNA synthetase upon phenylalanine restriction

Abstract The effect of phenylalanine restriction on the level of expression of phenylalanyl-tRNA synthetase from cultured Chinese hamster ovary cells was investigated. By lowering the phenylalanine concentration from 200 to 2 μM, cell growth was arrested, tRNA Phe aminoacylation level was rapidly and specifically decreased and phenylalanyl-tRNA synthetase was derepressed. The progressive 2-fold elevation of phenylalanyl- tRNA synthetase level was determined by activity measurement and immunotitration. None of the other aminoacyl-tRNA synthetases tested were significantly affected.