Differences in intracellular distribution of plasminogen activator in growing, confluent, and transformed 3T3 cells.

Abstract

The intracellular distribution of plasminogen activator in growing, confluent and [SV-40] transformed [mouse neoplastic fibroblast] 3T3 cells was investigated by using sucrose density gradient centrifugation. In confluent cells, which do not release plasminogen activator extracellularly, most of the activity was found in a heavy membrane fraction. In growing and transformed 3T3 cells, which do release plasminogen activator extracellularly in large amounts, most of the activity was found in lighter, plasma membrane-enriched fractions. A correlation between its presence in the light membrane fractions and the ability of the cells to release the plasminogen activator extracellularly is made.