Protein folding. Translational tuning optimizes nascent protein folding in cells.

In cells, biosynthetic machinery coordinates protein synthesis and folding to optimize efficiency and minimize off-pathway outcomes. However, it has been difficult to delineate experimentally the mechanisms responsible. Using fluorescence resonance energy transfer, we studied cotranslational folding of the first nucleotide-binding domain from the cystic fibrosis transmembrane conductance regulator.

Tryptase's potent mitogenic effects in human airway smooth muscle cells are via nonproteolytic actions.

We reported previously that mast cell tryptase is a growth factor for dog tracheal smooth muscle cells. The goals of our current experiments were to determine if tryptase also is mitogenic in cultured human airway smooth muscle cells, to compare its strength as a growth factor with that of other mitogenic serine proteases, and to determine whether its proteolytic actions are required for mitogenesis. Highly purified preparations of human lung beta-tryptase (1-30 nM) caused dose-dependent increases in DNA synthesis in human airway smooth muscle cells.