REDOX REGULATION OF BRN-2 N-OCT-3 POU DOMAIN DNA-BINDING ACTIVITY ANDPROTEOLYTIC FORMATION OF N-OCT-5 DURING MELANOMA CELL NUCLEAR EXTRACTION/

Reversible oxidation sensitivity of N-Oct-3 DNA binding activity was s een when melanoma extracts and recombinant Brn-2 protein were treated with a variety of metals, hydrogen peroxide and the cysteine disulphid e bond forming agent diamide. Western blot analysis of diamide-oxidize d N-Oct-3 protein indicated that this was likely to be due to intramol ecular disulphide bonding. The potential role of oxidative loss of N-O ct-3 DNA binding activity is discussed in relation to redox changes th at may occur during the early phase of apoptosis in neuronal cell line s and tissues. Brn-2 C-terminal antibody Western blot analysis of mela noma cell line nuclear extracts prepared using a combination of sodium dodecyl sulphate and NP-40 detergent cell lysis procedures demonstrat ed the formation of N-Oct-5 DNA binding activity via N-terminal proteo lytic clipping of Brn-2/N-Oct-3. (C) 1998 Rapid Science Ltd.