Reactome: A Curated Pathway Database

JNK (c-Jun kinases) phosphorylation and activation mediated by activated human TAK1 (R-HSA-450321)

Species Homo sapiens


C-Jun NH2 terminal kinases (JNKs) are an evolutionarily conserved family of serine/threonine protein kinases, that belong to mitogen activated protein kinase family (MAPKs - also known as stress-activated protein kinases, SAPKs). The JNK pathway is activated by heat shock, or inflammatory cytokines, or UV radiation.

The JNKs are encoded by at least three genes: JNK1/SAPK-gamma, JNK2/SAPK-alpha and JNK3/ SAPK-beta. The first two are ubiquitously expressed, whereas the JNK3 protein is found mainly in brain and to a lesser extent in heart and testes. As a result of alternative gene splicing all cells express distinct active forms of JNK from 46 to 55 kDa in size. Sequence alignment of these different products shows homologies of >80%. In spite of this similarity, the multiple JNK isoforms differ in their ability to bind and phosphorylate different target proteins, thus leading to the distinctive cellular processes: induction of apoptosis, or enhancment of cell survival, or proliferation.

Activation of JNKs is mediated by activated TAK1 which phosphorylates two dual specificity enzymes MKK4 (MAPK kinase 4) and MKK7(MAPK kinase 7).

Locations in the PathwayBrowser
Immune System(Homo sapiens)

TRAF6 Mediated Induction of proinflammatory cytokines(Homo sapiens)
Additional Information
Compartment cytosol , nucleoplasm
GO Biological Process JNK cascade (0007254)
Cross References
Database Identifier
BioModels Database BIOMD0000000468, BIOMD0000000466, BIOMD0000000477, BIOMD0000000504
Inferred Entries
Orthologous events