RELATIONSHIP BETWEEN PHOSPHATIDYLCHOLINE BIOSYNTHESIS AND CELLULAR COMMITMENT IN CONCANAVALIN A-STIMULATED LYMPHOCYTES

The incorporation of [14C]choline into phosphatidylcholine was studied in lymphocyte cultures exposed to concanavalin A (ConA). The lectin was found to induce an increase in the incorporation of the label with following features: 1. 1. It occurs very promptly after exposure. 2. 2. It is not elicited by a non-mitogenic lectin. 3. 3. The increase in the early stage is proportional to lectin concentration. 4. 4. It can be terminated by a competitive inhibitor of ConA binding. 5. 5. The extent of the increase shows a correlation with the rate of cellular commitment to initiate DNA synthesis. These results suggest that in the mitogenic stimulation of T lymphocytes enhanced synthesis of membrane phospholipids is a precommitment event. © 1979.