A researcher discovers pancreatic beta cells expressing normal insulin receptors yet exhibiting reduced glucose-stimulated insulin secretion (GSIS). Which mechanism best explains this phenomenon, assuming normal insulin receptor signaling?

💡 Explanation

Reduced GLUT4 translocation to the cell membrane decreases glucose uptake, which reduces the glucose available for metabolism, thereby impairing GSIS. This occurs because GLUT4 is the primary glucose transporter in pancreatic beta cells; therefore, diminished translocation directly limits glucose-stimulated insulin secretion, rather than altering glucokinase activity or other downstream signaling components.

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