Hormonal regulation of protein synthesis in cultured kidney cells

Calcitonin-induced changes in gene expression at the level of protein synthesis were examined in cultured porcine kidney cells (LLC-PK1) using two-dimensional gel electrophoresis of [35S]methionine-labeled polypeptides. Twelve intracellular polypeptides showed reproducible changes in the relative intensity of labeling. From that set of polypeptides ten showed an increase and two a decrease in the labeling intensity after calcitonin treatment. One of the induced polypeptides was identified as plasminogen activator and two others were shown to be related to cytokeratins. The labeling of two induced and well-separated polypeptides of 70K and 95K Mr was quantitated and correlated with an increase in secretion of plasminogen activator.