Fig 4

(A, B) VEGFA levels in HEK293 (A) and HUVEC (B) cells stably transfected with SerRS^WT, SerRS^AA, or SerRS^DD under normoxia or hypoxia conditions were measured by ELISA and normalized to total proteins in cell lysates. (means ± SEM, n = 2 biological replicates, *p < 0.05, **p < 0.05, n.s., Student t test). The SerRS protein levels were shown by western blot below the bar graph. (C, D) Endothelial cell tube formation assay (C) and quantification (D) using HUVEC cells treated with indicated conditional medium from wild-type or mutant SerRS stably transfected donor HUVEC cells cultured under normoxia or hypoxia conditions. The cartoon describes the experimental setup. The total length of tubules was measured using Image J software (means ± SEM, n = 3, biological replicates, *p < 0.05, **p < 0.01, ***p < 0.001, n.s., Student t test). SeeS1 Data for quantitative data and statistical analysis. See S2 Data for original, uncropped images supporting blots and gel results. HUVEC, human umbilical vein endothelial cell; n.s., not significant; SerRS, seryl-tRNA synthetase; SerRS^AA, S101A/S241A; SerRS^DD, S101D/S241D; SerRS^WT, wild-type SerRS; VEGFA, vascular endothelial growth factor A.