Objective To identify the mechanisms underlying xCT deficiency by high-resolution proteomic analysis of differential protein expression in Sut and wild melanocytes .Methods The proteins,extracted from Sut and wild melano-cytes,were analyzed by two dimensional electrophoresis and PDQuest software .Subsequent MALDI-TOF mass spectrometry analysis was carried out .The protein identification was based on peptide mass fingerprint combined with the pI and the rela -tive molecular mass ( Mr) .Sequence coverage was performed with the Peptldent software on the NCBnlm website .Also,the autophagy marker protein LC3-Ⅱ, and the autophagic cell death marker protein Beclin 1 were detected by Western blotting . Results and Conclusion Twenty apparently upregulated or downregulated proteins were identified .Strikingly, important modifications in regulators of trafficking and organization of vesicles and autophagy ( Anxa3; Hist 1h2bk, NDRG1, and CaM) and in regulators of invasion and metastasis of carcinoma (S100A-4;S100A-6 and vimentin)are likely to account for dysfunctions in cell viability and cell-extracellular adhesion .These results indicate that the proteins regulating autophagy , vesicles trafficking and MAP kinase related pathways are activated and play a role in xCT-deficiency .