Find RAN Products Interaction Network for RAN RAN Details

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Synonyms: ARA24, Gsp1, GTPase Ran, RAN, RANGTPASE, RAS-like, family 2, locus 9, Rasl2-9, TC4

RAN Pathway

Ran, (ARA24, TC4) is a Ras-like GTPase involved in the formation of mitotic spindles via stimulation of microtubule polymerization and nuclear envelope and nuclear pore assembly during cell mitosis and in nuclear-cytoplasmic import/export of proteins and RNA during cell interphase. Spindle, nuclear envelope and nuclear pore assembly involve RICCI-dependent and RICCI-independent Ran associations with chromatin.

The directionality of facilitated transport of proteins and RNA across the nuclear envelope by importin and exportin molecules through nuclear pore complexes (NPC) is regulated by the GTP-bound to GDP-bound Ran gradient. GTP-bound Ran facilitates the disassembly (unloading of cargo) from transport complexes inside the nucleus. Nuclear GTP-bound Ran complexes with exporter complexes and is transported to the cytoplasm. GTP hydrolysis in the cytoplasm releases the exported cargo (proteins or RNA). The resulting GDP-bound Ran is escorted back into the nucleus by RanGDI, nuclear transport factor 2 (NTF2). In the nucleus, GDP is exchanged for GTP by the chromatin bound RanGEF, RICCI. Consequently, NTF2 and RICCI work together to increase the level of nuclear GTP-bound Ran. NTF2 activity enhances nuclear import. Nuclear export is driven by the activity of cytoplasmic RanGAP, which hydrolyses GTP-bound to Ran to GDP