MAPK8 Research Reagents

MAPK8 Background

The MAPK8 gene encodes mitogen-activated protein kinase 8, an enzyme also known as JNK1 ^[1][2]. JNK1 is ubiquitously expressed ^[2]. As a serine/threonine-protein kinase, MAPK8/JNK1 is involved in various processes such as cell proliferation, differentiation, migration, transformation, and apoptosis. Extracellular stimuli such as proinflammatory cytokines or physical stress stimulate the stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) signaling pathway. In this cascade, two dual specificity kinases MAP2K4/MKK4 and MAP2K7/MKK7 phosphorylate and activate MAPK8/JNK1. In turn, MAPK8/JNK1 phosphorylates many transcription factors, primarily components of AP-1 such as JUN, JDP2, and ATF2 and thus regulates AP-1 transcriptional activity, eventually inducing cell proliferation, differentiation and stress responses ^[3-6]. Recently, it was demonstrated that JNK1 signaling plays a crucial role in the central nervous system (CNS) and in the pituitary to control systemic glucose and lipid metabolism partially through regulation of hormones involved in growth and energy expenditure ^[7].

[1] Dérijard B, Hibi M, et al. JNK1: a protein kinase stimulated by UV light and Ha-Ras that binds and phosphorylates the c-Jun activation domain [J]. Cell. 1994, 76 (6): 1025–37.
[2] Davis RJ. Signal transduction by the JNK group of MAP kinases [J]. Cell 2000;103:239–252.
[3] Gupta S, Barrett T, et al. Selective interaction of JNK protein kinase isoforms with transcription factors [J]. EMBO J. 1996, 15 (11): 2760–70.
[4] Dérijard B, Hibi M, et al. JNK1: a protein kinase stimulated by UV light and Ha-Ras that binds and phosphorylates the c-Jun activation domain [J]. Cell 1994, 76: 1025–1037.
[5] Kyriakis J, Banerjee P, The stress-activated protein kinase subfamily of c-Jun kinases [J]. Nature 1994, 369: 156–160.
[6] Nishina H, Wada T, et al. Physiological roles of SAPK/JNK signaling pathway [J]. J Biochem. 2004 Aug;136(2):123-6.
[7] Belgardt BF1, Mauer J, et al. Novel roles for JNK1 in metabolism [J]. Aging (Albany NY). 2010 Sep;2(9):621-6.