Human, melanoma, p62/SQSTM1, quantitative proteomics

p62/SQSTM1 was identified as a modulator of metastatic genes selectively enriched in melanoma in autophagy independent manner. iTRAQ quantitative proteomic approach was performed in melanoma cell lines (SK-Mel-103 and UACC-62) deficient for p62 to identify downstream effectors of p62. Similar studies were performed for ATG5, a core component of autophagy, as a reference for autophagy-associated changes in protein abundance. Additionally, melanoma cells were subjected to affinity purification (AP-MS) to identify the interactors of p62. Overall, these studies underscore a novel unexpected role of p62 regulating the stability of prometastatic factors via the interaction with RNA Binding Proteins, thus leading to the inhibition of protein translation.