What happens to Ran-GTP after it aids in cargo release during nuclear export?

After aiding in cargo release during nuclear export, Ran-GTP is hydrolyzed to Ran-GDP. This hydrolysis is a critical part of the nuclear transport cycle. When the export receptor, which is bound to the cargo, reaches the cytoplasm, the Ran-GTP is converted to Ran-GDP by the action of RanGAP (Ran GTPase-activating protein).

The conversion from Ran-GTP to Ran-GDP releases the cargo from the receptor, as the binding affinity between the receptor and the cargo is significantly lower when Ran is in its GDP-bound form. This step is essential because it allows the receptor to be recycled back into the nucleus to pick up more cargo.

Through this process, Ran-GTP's role in facilitating cargo release is concluded, and the hydrolysis to Ran-GDP ensures that the transport cycle can continue effectively by allowing the receptor to reset and prepare for another round of cargo transport.