MAP kinase cascade

The MAP kinase cascade is made up of three components:

1. MAP kinase kinase kinase (MAPKKK) or otherwise known as Raf.
2. MAP kinase kinase (MAPKK) or otherwise known as Mek.
3. MAP kinase (MAPK) or otherwise known as Erk.
   

Firstly an activated Ras protein triggers the Map kinase cascade and then the signal is passed on from one component to the next by phosphorylating the next component in line and therefore activating it. This is the step by step process:

1. MAPKKK 'receives the signal' from the Ras and then phosphorylates and activates MAPKK.
2. MAPKK then phosphorylates and activates MAPK.
3. The MAPK can then pass on the signal to other appropriate proteins so that it is carried to its final destination and eventually lead to a response to the initial signal .