Identification of Nuclear Localization Signal Sequence of PNRC1

To identify nuclear localization signal sequence (NLS) of proline-rich nuclear receptor coregulator protein 1 (PNRC1), vectors expressing green fluorescence protein(GFP)-tagged PNRC1 and GFP-tagged PNRC1 mutant with the putative NLS(aa 94-101, PKKRRKKK) deletion were generated then transfected into mammalian cells. The subcellular localization of PNRC1 and putative NLS deleted PNRC1 were examined by confocal microscope. In addition, recombinants expressing GFP-tagged putative NLS and GFP-tagged cytoplasm protein fused to putative NLS were constructsed, the subcellular localization of these NLS fusion proteins were examined in the transfected cells accordingly. The results demonstrated the native PNRC1 localized to the nucleus as expected, whereas the PNRC1 mutant with the putative NLS deletion primarily localized in the cytoplasm. The putative NLS of PNRC1 was found to be able to drive GFP and other cytoplasm protein into nucleus when it was fused to these proteins. We conclude that the putative NLS within PNRC1 indeed has a potent activity to mediate protein nuclear transportation.