Transcriptional and posttranslational regulation of a membrane nutrient transporter

Abstract

A laboratory exercise illustrating the metabolic regulation of a plasma membrane transporter was devised. A simple colorimetric assay allows the determination of the yeast maltose permease activity under different conditions, and thus the induction of the transporter by maltose and its repression by glucose can be easily demonstrated. The laboratory exercise also shows that glucose regulates the expression of the transporter at the plasma membrane by promoting its inactivation and endocytosis. The intracellular trafficking of the transporter under these conditions can be further illustrated using a maltose permease tagged with the green fluorescent protein. © 2002 by The International Union of Biochemistry and Molecular Biology.