FIG. 13.

Modes of substrate recognition by JNK. Active JNK appears likely to use at least three different modes of substrate recognition. For direct substrate recognition, the amino acids surrounding the residue to be phosphorylated in the substrate protein are recognized at the active site of the kinase. For both docking domain substrates and scaffolded substrates, this requirement for direct substrate recognition at the active site must also be fulfilled, but there are additional sites for substrate recognition. A docking domain on the substrate itself may enhance the interaction with the kinase, and similarly, the interaction with a scaffold protein that can also interact with the kinase will also increase the recognition of the substrate by the kinase.