Abstract: ObjectiveTo explore the subcellular localization of tumor-related gene MIP， the changes and the co-localization when MIP was co-transfected along with its interacting protein FASP1 or MafF into HeLa cells. MethodsUsing prediction and analysis softwares about protein structure and subcellular localization online, the possible structure and subcellular location of MIP protein were analyzed. Combined analysis results, fluorescent fusion protein tracer technique and confocal laser scanning microscope were used to observe and compare the subcellular localization of MIP in HeLa cells transfected with Pegfp-C1-MIP or Pegfp-N2-MIP alone. Then pDsRed-FASP1 or pDsRed-MafF was transfected alone， or co-transfected with MIP-GFP. After observing the distribution of green or red fluorescent proteins, the subcellular localization changes of each protein were compared and co-localization conditions were analyzed. ResultsWhen it was transfected alone, MIP was mainly distributed in cytoplasm unevenly. MIP’s subcellular location had a slight change as GFP was fused to its N-or C-terminal. The uneven distribution of MIP-GFP was more typical than GFP-MIP and showed a significant punctate accumulation in cytoplasm. When pDsRed-FASP1 was transfected alone, FASP1 dispersed in cytoplasm. After co-transfection, the subcellualr distributions of FASP1 and MIP had no major changes and they co-localized in cytoplasm. When pDsRed-MafF was transfected alone, MafF dispersed in nucleus. But the subcellular localizations were both significantly changed in HeLa cells co-transfected with MIP and MafF, and thus they could c-localize in multiple nucleoli. ConclusionThis study demonstrated that MIP could interact with FASP1 or MafF in different compartment of cells, which suggested that MIP could be an important signaling molecule to comply different function in cytoplasm

Key words: MIP gene, FASP1, MafF, Subcellular localization, Fluorescent fusion protein, Confocal laser scanning microscope