The effect of serum on the transport and phosphorylation of 2‐deoxyglucose by untransformed and transformed mouse 3T3 cells

Serum starvation of growing and nongrowing (density-inhibited) mouse 3T3 cells resulted in decreased phosphorylation of 2-deoxy--D-glucose, while the time course of transport of this sugar remained unchanged. Serum starvation of SV40 transformed 3T3 cells (SV101) and spontaneously transformed 3T6 cells did not alter either the time course of transport, or phosphorylation of the sugar. Treatment of SV101 cells with 10(-4) M dibutyryl adenosine cyclic 3':5' monophosphate and 10(-3) M theophylline did not restore the capacity to regulate 2-deoxy-D-glucose phosphorylation when these cells were serum deprived. We conclude that serum factors are involved in the modulation of phosphorylation of 2-deoxy-D-glucose in 3T3 cells rather than its transport. This regulation is operative both in growing as well as nongrowing 3T3 cells. In contrast, transformed cells do not respond to this regulation of 2-deoxy-D-glucose phosphorylation.