File:Fig-8 The nucleocytoplasmic shuttling cycle of importin α.png

Fig-8:The nucleocytoplasmic shuttling cycle of importin α. (i) Importin α (α) forms a ternary complex with importin β (β) and cargo (blue circles). (ii) The ternary complex docks at the nuclear-pore complex (NPC) and (iii)translocates into the nucleus. (iv) Binding of Ran–GTP triggers the dissociation of the ternary complex. (v)Importin α binds to the exportin CAS–Ran–GTP complex and is exported to the cytoplasm. (vi) Ran–GAP-stimulated hydrolysis of GTP by Ran triggers the dissociation of the exportin complex and releases free importin α into the cytoplasm for another transport cycle. The recycling of importin β to the cytoplasm, and of Ran–GDP to the nucleus and its conversion to Ran–GTP are not shown.