a, b, Effect of (a) BCAT1 knockdown or (b) Gbp treatment on the intracellular concentrations of glutamate and BCAAs in K562 cells. The shCtrl or PBS control values were set as 100%. Error bars, s.e.m. n = 10 each for (a) and n = 3 each for (b). *P < 0.05, **P < 0.01. NS, not statistically significant (P > 0.05). c, AKT activation status in BCAT1- or MSI2-knockdown K562 cells. K562 cells treated with shCtrl, shBCAT1 or shMSI2 were analysed by western blotting for pAKT (at Thr308 or Ser473), total AKT, hBCAT1, hMSI2 and HSP90 levels. d, Effect of α-ketoglutarate supplementation on the colony-forming ability of BCAT1-knockdown cells. K562 cells transduced with shCtrl (−) or shBCAT1-d (+) were plated in triplicate with or without 1 mM dimethyl-α-ketoglutarate (KG) and/or 4 mM BCAAs as indicated. n = 3 technical replicates. Error bars, s.e.m. *P < 0.05, **P < 0.01. NS, not statistically significant (P > 0.05).