Erk3 and Erk4
Extracellular signal-regulated kinase 3 (Erk3) and Erk4 are atypical members of the mitogen-activated protein (MAP) kinase family of serine/threonine kinases. The Erk3 and Erk4 genes were originally identified in 1991 and 1992, by homology cloning with probes derived from the MAP kinase Erk1 (Boulton et al. 1991; Gonzalez et al. 1992). In human, Erk3 is encoded by the MAPK6 gene located on chromosome 15q21.2. The MAPK4 gene present on chromosome 18q21.1 encodes Erk4. The high sequence identity of Erk3 and Erk4 proteins and the similar organization of their genes indicate that the two proteins are true paralogs. It is noteworthy that MAPK6 and MAPK4 are the only MAP kinase genes that are restricted to the vertebrate lineage.
Structure of Erk3 and Erk4
- Boulton TG, Nye SH, Robbins DJ, Ip NY, Radziejewska E, Morgenbesser SD, DePinho RA, Panayotatos N, Cobb MH, Yancopoulos GD. ERKs: a family of protein-serine/threonine kinases that are activated and tyrosine phosphorylated in response to insulin and NGF. Cell. 1991;65:663–75.PubMedCrossRefGoogle Scholar
- Coulombe P, Rodier G, Pelletier S, Pellerin J, Meloche S. Rapid turnover of extracellular signal-regulated kinase 3 by the ubiquitin-proteasome pathway defines a novel paradigm of mitogen-activated protein kinase regulation during cellular differentiation. Mol Cell Biol. 2003;23:4542–58.PubMedCrossRefGoogle Scholar
- Rousseau J, Klinger S, Rachalski A, Turgeon B, Deleris P, Vigneault E, Poirier-Heon JF, Davoli MA, Mechawar N, El Mestikawy S, Cermakian N, Meloche S. Targeted inactivation of Mapk4 in mice reveals specific non-redundant unctions of Erk3/Erk4 subfamily mitogen-activated protein kinases. Mol Cell Biol. 2010;30:5752–63.PubMedCrossRefGoogle Scholar