The relationship between high-affinity binding of cytochalasin B to 3T3 cells and inhibition of sugar transport and cell motility.
Transport and motility inhibitors have been used to classify different types of high-affinity cytochalasin B (CB) binding sites in 3T3 cells. The potency of phloretin and phlorizin as inhibitors of sugar uptake paralleled their effectiveness in displacing high-affinity bound CB from the cells, indicating that the two compounds compete with CB for binding to sites associated with sugar transport proteins. On the other hand, cytochalasins D and E, which did not inhibit sugar uptake, inhibited binding of CB to a portion of the high-affinity sites, most probably those associated with actin-containing cytoskeletal-contractile structures. A small amount of high-affinity CB binding remained in the presence of both phloretin and cytochalasin E, indicating that the cells have a third class of sites which is not related to either sugar transport or cell motility, When isolated membranes were examined, it was found that a fraction of each class of high-affinity CB binding sites were associated with the fraction. In contrast, only sites sensitive to cytochalasin D were recovered in a soluble extract of the cells.
D000818:Animals; D001667:Binding, Competitive; D001692:Biological Transport / Q000187:drug effects; D050260:Carbohydrate Metabolism; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects; D003571:Cytochalasin B / Q000378:metabolism*; D003572:Cytochalasins / Q000494:pharmacology; D003847:Deoxyglucose / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D010693:Phloretin / Q000494:pharmacology; D010695:Phlorhizin / Q000494:pharmacology
D003572:Cytochalasins; D003571:Cytochalasin B; D003847:Deoxyglucose; D010695:Phlorhizin; D010693:Phloretin