Recombinant Human GTP-binding nuclear protein Ran (RAN) fragment (residues 2-216) is a high-purity protein preparation encompassing the complete Small GTPase Ran-type domain. This fragment serves as an essential tool for investigating nucleocytoplasmic transport mechanisms, mitotic spindle regulation, and androgen receptor-mediated signaling pathways in cellular and biochemical assays.

The full-length GTP-binding nuclear protein Ran is a crucial GTPase that regulates nucleocytoplasmic transport by cycling between GDP-bound (cytoplasmic) and GTP-bound (nuclear) states. It directs both nuclear import and export processes by controlling cargo loading and release through interaction with transport receptors, ensuring directional transport specificity. Beyond its transport functions, Ran plays critical roles in mitotic progression by triggering microtubule assembly at chromosomes and facilitating normal spindle formation through complexes with survivin and TPX2. The protein also modulates androgen receptor-mediated transactivation and negatively regulates VRK1/VRK2 kinase activity. Ran localizes predominantly to the nucleus during interphase but disperses throughout the cytoplasm during mitosis, with additional presence at the nuclear envelope, cytosol, and melanosomes, reflecting its diverse cellular functions.