diamide and Melanoma

Reversible oxidation sensitivity of N-Oct-3 DNA binding activity was seen when melanoma extracts and recombinant Brn-2 protein were treated with a variety of metals, hydrogen peroxide and the cysteine disulphide bond forming agent diamide. Western blot analysis of diamide-oxidized N-Oct-3 protein indicated that this was likely to be due to intramolecular disulphide bonding. The potential role of oxidative loss of N-Oct-3 DNA binding activity is discussed in relation to redox changes that may occur during the early phase of apoptosis in neuronal cell lines and tissues. Brn-2 C-terminal antibody Western blot analysis of melanoma cell line nuclear extracts prepared using a combination of sodium dodecyl sulphate and NP-40 detergent cell lysis procedures demonstrated the formation of N-Oct-5 DNA binding activity via N-terminal proteolytic clipping of Brn-2/N-Oct-3.

Topics: Animals; Blotting, Western; Cell Nucleus; COS Cells; Diamide; DNA-Binding Proteins; DNA, Neoplasm; Gene Expression Regulation, Neoplastic; HeLa Cells; Homeodomain Proteins; Humans; Hydrogen Peroxide; Melanoma; Melanoma, Experimental; Metals; Mice; Oxidation-Reduction; POU Domain Factors; Rabbits; Transcription Factors; Tumor Cells, Cultured