Kinase Group STE
Kinase Classification: STE Group
This group consists of three main families which sequentially activate each other to then activate the MAPK family. The Ste7 family directly phosphorylate MAPKs, and are also known as MAP2K, MEK, or MKKs; Ste11 members phosphorylate Ste7 kinases and are called MAP3K, while many Ste20 members (MAP4K) act on Ste11 kinases. These families are named after members of the canonical pheromone-responsive MAPK cascade in yeast. Distinct sets of Ste7 and Ste11 kinases are linked with specific classes of MAPK (Erk, Jnk, p38 and others) but some cross-talk is also seen.
MAP3K activity is also found in members of the TKL group, in kinases such as Raf and MLK, as well as in the 'Other' kinase, MOS.
The Ste20 (MAP4K) family is the largest of the three and is divided into many subfamilies. Some are implicated in MAPK cascades, while others are not and may have completely distinct functions.