 This difference in location of the accessory proteins in the Ran cycle leads to a high RanGTP to RanGDP ratio inside the nucleus and an inversely low RanGTP to RanGDP ratio outside the nucleus.In addition to a gradient of the nucleotide bound state of Ran, there is a gradient of the protein itself, with a higher concentration of Ran in the nucleus than in the cytoplasm.Cytoplasmic RanGDP is imported into the nucleus by the small protein NUTF2 (Nuclear Transport Factor 2), where RCC1 can then catalyze exchange of GDP for GTP on Ran.