What constitutes the driving force for transpo of proteins into and out of the nucleus?
No ATP is involved at any point in nuclear transpo. The driving force for the transpo comes indirectly from a gradient created by GTP hydrolysis. The key controlling factor is the allosteric GTPase, Ran. Ran is only able to hydrolyze GTP to GDP in the cytosol because this process must be activated by a GTPase-activating protein (GAP) that is only present in the cytosol. Reference: Harper; 30th edition
ATP hydrolysis within the cytosol
ATP hydrolysis within the nucleus
GTP hydrolysis within the cytosol
GTP hydrolysis within the nucleus
Structure and function of protein