Glucose transport in the yeast Kluyveromyces lactis. II. Transcriptional regulation of the glucose transporter gene RAG1.

The RAG1 gene encodes a membrane protein involved in the low-affinity glucose/fructose transport system of the yeast Kluyveromyees lactis. Analysis of steady-state mRNA levels analysis and quantitation of expression by β-galactosidase from RAG1-lacZ fusions assays revealed that the RAG1 gene was poorly expressed in cells grown under gluconeogenesis conditions, but was induced more than ten-fold when they were grown on various sugars. These sugars included glucose, fructose, mannose, sucrose, raffinose, as well as galactose