Kinase Family MAPK
The MAPKs (Mitogen Activated Protein Kinase) are the final kinases of the MAPK cascade, which relay signals from the cell surface for growth, stress and other responses. The best-known MAPKs include Erk, which relays growth signals from the ras/raf pathway and receptor kinases, and the JNK and p38 subfamilies, which relay various stress signals.
Most MAPKs have a specific TxY motif in their activation loop, in which both the T and Y are phosphorylated by MEK (MAP2K) kinases in order to activate them. Erk3 (~SeG) and nmo (TxE) are variants that lack the Y.
MAPK subfamilies include