MAPK

Mitogen-activated protein kinase
Identifiers
EC number	2.7.11.24
CAS number	142243-02-5
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

Mitogen-activated protein kinase (MAPK) is a type of enzyme involved in directing cellular responses to a diverse array of stimuli, such as mitogens, osmotic stress, heat shock and proinflammatory cytokines. They regulate cell functions including proliferation, gene expression, differentiation, mitosis, cell survival, and apoptosis.

Function

MAPKs are involved in directing cellular responses to a variety of external stress signals. They play a role in the control of cell functions including proliferation, gene expression, differentiation, mitosis, cell survival, and apoptosis. The MAPK family consists of several subfamilies, including the extracellular signal-regulated kinases (ERKs), the c-Jun N-terminal kinases (JNKs), and the p38 MAP kinases.

Pathway

The MAPK pathway is a signal transduction pathway that begins with the activation of a receptor on the cell surface and ends with a change in the function of the cell. This pathway includes several steps involving various protein kinases that activate one another in sequence:

1. A receptor on the cell surface receives a signal.
2. An adaptor molecule in the cell membrane responds by activating a G protein.
3. The G protein activates a MAP kinase kinase kinase (MAPKKK).
4. The MAPKKK activates a MAP kinase kinase (MAPKK).
5. The MAPKK activates a MAP kinase (MAPK).

Once activated, MAPKs translocate to the nucleus of the cell where they phosphorylate various transcription factors, thus influencing gene expression.

Clinical Significance

MAPKs are crucial in the development and progression of many diseases, including cancer, diabetes, and inflammatory diseases. Inhibitors of the MAPK signaling pathway are being studied for the treatment of these diseases.

See Also

• Signal transduction
• Protein kinase
• Cell signaling
• Extracellular signal-regulated kinases
• c-Jun N-terminal kinases
• p38 MAP kinases