E1B-19k does not Localize in Mitochondria nor Dimerize Bax even with the Staurosporine

Abstract

Purpose: The subcellular localization of E1B-19k has been known cytosol or nuclear membrane by immuno-histochemical staining and could dimerize with Bax to regulate cell death also known by the in-vitro immunoprecipitation. We planed to confirm this dimerization of E1B-19k with Bax in vivo in Cos-7 cells by using green fluorescent protein. Material and Method: We cloned E1B-19k and Bax into C3-EGFP. C3-EGFP-E1B-19k, C3-EGFP-Bax, and C3-EGFP-E1B-19k and pcDNA3-Bax were transfected into Cos-7 cells. We explored location of E1B-19k and Bax, and confirmed its dimerization with Bax in transfected living healthy Cos-7 cells by following green fluorescent protein of E1B-19k on the confocal microscope. Results: E1B-19k was located diffusely in cytoplasm and in nucleus but not in mitochondria. It prevented cell death from the apoptosis by staurosporine but its location was not changed. GFP-E1B-19k is not changed its intracellular location with Bax even with staurosporine. Conclusion: These results support that E1B-19k does not localize in mitochondria nor dimerize with Bax even with staurosporine. We could anticipate E1B-19k prevent cell death via the other dimerizing partner or pathways.