C-Jun N-terminal kinases

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Main article: Mitogen-activated protein kinase

mitogen-activated protein kinase 8
Identifiers
Symbol	MAPK8
Alt. Symbols	PRKM8
Entrez	5599
HUGO	6881
OMIM	601158
RefSeq	NM_002750
UniProt	P45983
Other data
Locus	Chr. 10 q11.2

mitogen-activated protein kinase 9
Identifiers
Symbol	MAPK9
Alt. Symbols	PRKM9
Entrez	5601
HUGO	6886
OMIM	602896
RefSeq	NM_002752
UniProt	P45984
Other data
Locus	Chr. 5 q35

mitogen-activated protein kinase 10
Identifiers
Symbol	MAPK10
Alt. Symbols	PRKM10
Entrez	5602
HUGO	6872
OMIM	602897
RefSeq	NM_002753
UniProt	P53779
Other data
Locus	Chr. 4 q22-q23

C-Jun N-terminal kinases (JNKs), originally identified as kinases that bind and phosphosphorylate c-Jun on Ser63 and Ser73 within its transcriptional activation domain, are mitogen-activated protein kinases which are responsive to stress stimuli, such as cytokines, ultraviolet irradiation, heat shock, and osmotic shock, and are involved in T cell differentiation and apoptosis.

Contents 1 Isoforms 2 Functions 3 External links 4 References

[edit] Isoforms

The c-Jun N-terminal kinases consist of ten isoforms deriving from the three genes JNK1, JNK2 and JNK3^[1]:

• JNK1 and JNK2 are ubiquitously distributed.
• By contrast, JNK3 is found mainly in neuronal tissue and testes.

[edit] Functions

JNK1 is involved in apoptosis, neurodegeneration, cell differentiation and proliferation, inflammatory conditions and cytokine production mediated by AP-1 (Activation Protein 1) such as RANTES, IL-8 and GM-CSF. ^[2]

Recently, JNK1 has been found to regulate Jun protein turnover by phosphorylation and activation of the ubiquitin ligase Itch.

JNKs can associate with scaffold proteins JNK Interacting Proteins as well as their upstream kinases JNKK1 and JNKK2 following their activation.

JNK, by phosphorylation, modifies the activity of numerous proteins that reside at the mitochondria or act in the nucleus. This way, JNK activity regulates several important cellular functions. Inflammatory signals, changes in levels of reactive oxygen species, Ultraviolet radiation, protein synthesis inhibitors, and a variety of stress stimuli can activate JNK. One way this activation may occur is through disruption of the conformation of sensitive protein phosphatase enzymes; specific phosphatases normally inhibit the activity of JNK itself and the activity of proteins linked to JNK activation.^[3]

[edit] External links

• MeSH JNK+Mitogen-Activated+Protein+Kinases

[edit] References

1. ^ Waetzig V, Herdegen T (2005). "Context-specific inhibition of JNKs: overcoming the dilemma of protection and damage". Br. J. Pharmacol 26 (9): 455–61. PMID 16054242. 
2. ^ Oltmanns U, Issa R, Sukkar M, John M, Chung K (2003). "Role of c-jun N-terminal kinase in the induced release of GM-CSF, RANTES and IL-8 from human airway smooth muscle cells". Br. J. Pharmacol. 139 (6): 1228–1234. doi:10.1038/sj.bjp.0705345. PMID 12871843. 
3. ^ Vlahopoulos S, Zoumpourlis V, (2004). "JNK: a key modulator of intracellular signaling". Biochemistry (Mosc). 69 (8): 844–854. doi:10.1023/B:BIRY.0000040215.02460.45. PMID 15377263. 

v • d • e Kinases: Serine/threonine-specific protein kinases (primarily EC 2.7.11) 2.7.11 Pyruvate dehydrogenase kinase - Protein kinase A - Protein kinase G Protein kinase C (Protein kinase Mζ) G-protein coupled receptor kinases (Rhodopsin, Beta adrenergic receptor) Ca2+/calmodulin-dependent (Elongation factor 2 kinase, Myosin light-chain) Phosphorylase - Cyclin-dependent Mitogen-activated (Extracellular signal-regulated, C-Jun N-terminal (MAPK8, MAPK9), P38 mitogen-activated protein) MAP3K - GSK-3 - AMP-activated 2.7.12 MAP2K (1, 2, 3, 4, 5, 6, 7) 2.7.1.37, or unknown Anti-Mullerian hormone receptor - Ataxia telangiectasia mutated - Aurora (A, B) - Mammalian target of rapamycin - Bone morphogenetic protein receptors (1, 2) - CDKL5 - c-Raf - EIF-2 - Ribosomal s6 - Protein kinase B - PDK1