Insulin receptor tyrosine kinase autophosphorylation triggers a signalling cascade culminating in translocation of which glucose transporter to the plasma membrane of adipocytes and skeletal muscle?

• A GLUT1
• B GLUT2
• C GLUT3
• D GLUT4 ✓

Explanation

Insulin receptor autophosphorylation activates IRS-1 → PI3K → PDK1 → Akt (PKB). Akt phosphorylates and inactivates Akt substrate of 160 kDa (AS160), releasing GLUT4-containing vesicles from intracellular sequestration, causing translocation to the cell surface of adipocytes and skeletal muscle. GLUT1 is ubiquitous and constitutively expressed. GLUT2 is in hepatocytes and pancreatic β-cells (high Km, glucose sensor). GLUT3 is the high-affinity neuronal transporter.

Reference: Harper's Illustrated Biochemistry, 32nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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