Regulation of a heterologous glucose transporter promoter in chicken embryo fibroblasts.

GLUT1 is a glucose transporter responsible for increased cellular glucose uptake upon oncogenic transformation or mitogenic stimulation. This is associated with transcriptional activation of the GLUT1 gene. Three regions in the mouse GLUT1 gene mediate this regulation (the promoter and two enhancers). In contrast, chicken GLUT1 transcription is completely uninducible, suggesting either avian signal transduction events are different or the chicken GLUT1 gene lacks these transcriptional control elements. To distinguish between these possibilities, reporter plasmids containing mouse GLUT1 control elements in rodent and avian fibroblasts were compared. These elements function within chicken cells, suggesting that signaling pathways are similar to mouse cells but that the avian GLUT1 gene lacks the control elements necessary to respond to them.