The recognition of AUG start codon and selection of the open reading frame (ORF) is fundamental to protein biosynthesis. Defect in the start codon selection adversely affectproteome and have a pleiotropic effect on cellular function. Using proteomic techniques, we identified differential protein expression patterns in the translation initiation defectivehyper GTPaseeIF5G31R mutant cells. Consistently, we observed altered proteome involved in protein catabolism, nucleotide metabolism, fatty acid metabolism, glycolysis, and autophagy.The utilization of the upstream UUG codons by the eIF5G31R mutation caused downregulation of uridylate kinase expression and DNA damage. The eIF5G31R mutant cells showed lower Glutathione levels, high ROS activity, and sensitivity to H2O2.