REGULATION OF A HETEROLOGOUS GLUCOSE-TRANSPORTER PROMOTER IN CHICKEN-EMBRYO FIBROBLASTS

GLUT1 is a glucose transporter responsible for increased cellular gluc ose uptake upon oncogenic transformation or mitogenic stimulation. Thi s is associated with transcriptional activation of the GLUT1 gene. Thr ee regions in the mouse GLUT1 gene mediate this regulation (the promot er and two enhancers). In contrast, chicken GLUT1 transcription is com pletely uninducible, suggesting either avian signal transduction event s 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 cell s, suggesting that signaling pathways are similar to mouse cells but t hat the avian GLUT1 gene lacks the control elements necessary to respo nd to them. (C) 1998 Academic Press.