MAPK signaling pathway

The mitogen-activated protein kinase (MAPK) cascade is a highly conserved module that is involved in various cellular functions, including cell proliferation, differentiation and migration. Mammals express at least four distinctly regulated groups of MAPKs, extracellular signal-related kinases (ERK)-1/2, Jun amino-terminal kinases (JNK1/2/3), p38 proteins (p38alpha/beta/gamma/delta) and ERK5, that are activated by specific MAPKKs: MEK1/2 for ERK1/2, MKK3/6 for the p38, MKK4/7 (JNKK1/2) for the JNKs, and MEK5 for ERK5. Each MAPKK, however, can be activated by more than one MAPKKK, increasing the complexity and diversity of MAPK signalling. Presumably each MAPKKK confers responsiveness to distinct stimuli. For example, activation of ERK1/2 by growth factors depends on the MAPKKK c-Raf, but other MAPKKKs may activate ERK1/2 in response to pro-inflammatory stimuli. Source: KEGG http://www.genome.jp/dbget-bin/www_bget?pathway:map04010

丝裂原活化蛋白激酶（MAPK）级联反应是一种高度保守的模块，它参与多种细胞功能，包括细胞增殖、分化和迁移。哺乳动物表达至少四组受严格调控的MAPK，即细胞外信号相关激酶（ERK）-1/2、Jun 氨基末端激酶（JNK1/2/3）、p38 蛋白（p38alpha/beta/gamma/delta）以及ERK5，这些激酶由特定的MAPKK激活：MEK1/2 激活ERK1/2，MKK3/6 激活p38，MKK4/7（JNKK1/2）激活JNKs，MEK5 激活ERK5。然而，每个MAPKK均可被多个MAPKKK激活，这增加了MAPK信号传导的复杂性和多样性。推测每个MAPKKK赋予了对不同刺激的响应能力。例如，生长因子激活ERK1/2依赖于MAPKKK c-Raf，但其他MAPKKKs可能在促炎刺激下激活ERK1/2。来源：KEGG http://www.genome.jp/dbget-bin/www_bget?pathway:map04010