Following a large number of phosphorylation events at the cell membrane, the signal pathway culminates by releasing the GSV (GLUT4 storage vesicle) pool from its holding pattern. Clicking on each of the
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In this example AKT2 leaves the cell membrane and travels to the GLUT4 storage vesicle (GSV) pool.
The GSV pool is a group of membrane vesicles that contain GLUT4 transporter proteins. When embedded in the cell membrane, these transporters allow glucose to enter the cell.
The GSV pool is held in a recycling pattern near the cell membrane when glucose levels outside of the cell are low, and insulin is not present.
The GSVs are prevented from moving toward the cell membrane when the RAB proteins that control this movement are inactivated.
When AKT2 reaches the GSV pool,
it activates the RAB proteins by interacting with the kinase proteins that were responsible for keeping the RAB proteins inactive.
The vesicles in the GSV pool are then free to move to the cell's plasma membrane, where they merge and deposit a large number of GLUT4 transporters into the membrane.
The increase in GLUT4 transporters then allows a greatly increased level of glucose to be absorbed from outside the cell.