Increased glucose transport in ras-transformed fibroblasts: a possible role for N-glycosylation of GLUT1.
2-Deoxyglucose uptake was enhanced in ts371 KiMuSV-NRK cells when growing at the permissive temperature to allow the expression of a transforming p21 ras protein. This change is due to a decrease in the K(m) by approximately 2.5-fold without affecting the V(max) of the transporter. The amount of the GLUT1 glucose transporter dit not increase as deduced from immunoblot experiments on total membranes. Nevertheless, ras-transformed GLUT1 displays a higher molecular mass due to an increased N-glycosylation of the protein. Experiments made in tunicamycin-treated cells indicates that a higher glycosylation is responsible for the increase in 2-deoxyglucose uptake in ras-transformed cells.
Onetti
R
R
Departament de Bioquímica i Biologia Molecular, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra, Spain.
Baulida
J
J
Bassols
A
A
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects / Q000235:genetics; D002461:Cell Line, Transformed; D003847:Deoxyglucose / Q000378:metabolism; D011905:Genes, ras; D005947:Glucose / Q000378:metabolism*; D051272:Glucose Transporter Type 1; D006031:Glycosylation; D007700:Kinetics; D009004:Monosaccharide Transport Proteins / Q000737:chemistry / Q000378:metabolism*; D051381:Rats; D013696:Temperature; D014415:Tunicamycin / Q000494:pharmacology
D051272:Glucose Transporter Type 1; D009004:Monosaccharide Transport Proteins; C495679:Slc2a1 protein, rat; D014415:Tunicamycin; D003847:Deoxyglucose; D005947:Glucose