Localization of overexpressed MDA-7/IL-24 protein

Objective To find out the role of GFP-tag on the localization of overexpressed MDA-7/IL-24 protein.Methods Recombinant plasmids pEGFP-C1-mda-7/IL-24 with GFP-tag at NH4-terminal and pEGFP-N3-mda-7/IL-24 with GFP-tag at COOH-terminal were constructed.After the recombinant plasmids were transfected transiently into monkey embryonic kidney cell of Cos7 for 48 hours,nucleus of Cos7 cells were dyed with Hoechst 33258.Distribution of the fusion proteins GFP-tag-MDA-7/IL-24 was observed under the fluorescence microscope.Results Sequential analysis proved that recombinant plasmids pEGFP-C1-mda-7/IL-24 and pEGFP-N3-mda-7/IL-24 were constructed successfully.In the positive cells for MDA-7/IL-24 fusion protein with GFP-tag at NH4-terminal,the GFP was found to be distributed equally both in the cytoplasm and the nucleus.The GFP in the positive cells for MDA-7/IL-24 fusion protein with GFP-tag at COOH-terminal was found to be localized around the outer part of the nuclear membrane and the cytoplasm.Conclusion The different position of GFP-tag in the fusion protein influenced the distribution of overexpressed MDA-7/IL-24 markedly.