DOWN-REGULATION OF CYCLIN-F LEVELS DURING NERVE GROWTH FACTOR-INDUCEDDIFFERENTIATION OF PC12 CELLS

Treatment with nerve growth factor (NGF) produces a marked decrease of cyclin F levels in PC12EY cells. This decrease is prevented by the si multaneous addition of K-252a. A smaller decrease is observed when the cells are treated with fibroblast growth factor, but the addition of epidermal growth factor has no comparable effect; Time course studies show that the decrease in cyclin F precedes the changes produced by NG F in the distribution of cells within the cell cycle. The data suggest that cyclin F is involved in NGF-mediated cell cycle events during th e differentiation of PC12EY cells. (C) 1996 Academic Press, Inc.