Mitogen-activated protein kinase

Function

Mitogen-activated protein kinase (MAPK) also known as Extracellular Signal-Regulated Kinase (ERK) are serine/threonine kinases which regulate various cellular activities in response to extracellular stimuli by mitogens, heat shock and more. MAPK is part of the MAPK cascade which consists of MAPK, MAP2K and MAP3K which are activated by phosphorylation^[1].

• MAPK1 or ERK2 and MAPK3 are activated in response to growth factors. For MAPK1 representations see Michael Roberts/BIOL115/ERK2.
  
• MAPK6 is activated by phorbol esters.
  
• MAPK7 is activated by stress stimuli.
  
• MAPK8 (called also c-Jun N-terminal kinase 1 or JNK1), MAPK9, MAPK10 (called also c-Jun N-terminal kinase 3 or JNK3), MAPK11, MAPK12, MAPK13, MAPK14 are stress-activated.
  
• MAPK11 (also called p38-β MAPK), MAPK12 (also called p38-γ MAPK), MAPK13 (also called p38-δ MAPK), MAPK14 (also called p38-α MAPK) belongs to the class called p38 MAPK.

Relevance

MAPK cascade is elevated in cancer cells, hence MAPK inhibitors are tested as potential cancer therapy.

Disease

MAPK14 is associated with acquired hyperkeratosis and prostate transitional cell carcinoma.

Structural highlights

Inhibitors of MAPK bind in its ATP-binding site^[2].