Modulation of Human DNA Topoisomerase IIα Function by Interaction with 14-3-3ε

摘要: Human DNA topoisomerase IIalpha (topo II), a ubiquitous nuclear enzyme, is essential for normal and neoplastic cellular proliferation survival. Several common anticancer drugs exert their cytotoxic effects through interaction with topo II. In experimental systems, altered II expression has been associated the appearance of drug resistance. This mechanism, however, does not adequately account clinical cases resistance to II-directed drugs. Modulation by protein-protein interactions represents one mechanism regulation that extensively defined. Our laboratory identified 14-3-3epsilon as II-interacting protein. this study, glutathione S-transferase co-precipitation, affinity column chromatography, immunoprecipitations confirm authenticity these interactions. Three assays evaluate impact on distinct functional properties. Using both modified alkaline comet assay cleavage assay, we demonstrate negatively affects ability chemotherapeutic, etoposide, trap in cleavable complexes DNA, thereby preventing strand breaks. By electrophoretic mobility shift appears be due reduced binding activity. The association 14-3-3 proteins extend all isoforms. No protein or disruption function was observed 14-3-3final sigma.