Module 2: Figure MAPK signalling
Organization of the main mitogen-activated protein kinase (MAPK) signalling pathways.
The generic pathway on the left summarizes the sequential organization of the mitogen-activated protein kinase (MAPK) signalling system. External stimuli act through a variety of transducers to stimulate the first element of the signalling pathway, which is one of the 14 different MAPK kinase kinases (MAPKKKs). These MAPKKKs then phosphorylate the next element, which is one of the seven MAPK kinases (MAPKKs). This MAPKK then phosphorylates one of the 12 MAPKs, the names of which define the different signalling pathways. The three main pathways are the ERK pathway (Module 2: Figure ERK signalling), the JNK pathway (Module 2: Figure JNK signalling) and the p38 pathway. The components that make up these different signalling pathways are summarized in the MAPK signalling toolkit (Module 2: Table MAPK signalling toolkit).