MAPK3（mitogen-activated protein kinase 3），癌症关联基因，基因ID：5595，这个基因编码的蛋白质是MAP激酶家族的一员。MAP激酶，也称为细胞外信号调节激酶（ERK），作用于一个信号级联，调节各种细胞过程，如增殖、分化和细胞周期进程，以响应各种细胞外信号。这种激酶被上游激酶激活，导致其移位到核，在那里它磷酸化核靶点。已经描述了编码不同蛋白质亚型的选择性剪接转录变体。[由RefSeq提供，2008年7月]The protein encoded by this gene is a member of the MAP kinase family. MAP kinases， also known as extracellular signal-regulated kinases (ERKs)， act in a signaling cascade that regulates various cellular processes such as proliferation， differentiation， and cell cycle progression in response to a variety of extracellular signals. This kinase is activated by upstream kinases， resulting in its translocation to the nucleus where it phosphorylates nuclear targets. Alternatively spliced transcript variants encoding different protein isoforms have been described. [provided by RefSeq， Jul 2008]。