How does the GTP-bound form of a GTP-binding protein switch to a GDP-bound form?
A. It releases GTP and takes up GDP from the mitochondrion.
B. In the presence of high concentrations of GDP, it trades GTP for GDP.
C. It releases GTP and takes up GDP from the cytosol.
D. It hydrolyzes GTP releasing a phosphate.
E. It interacts with a phosphatase, which removes a phosphate from GTP.