Lechner C, Zahalka M A, Giot J F, Møller N P, Ullrich A
Department of Molecular Biology, Max-Planck-Institut für Biochemie, Martinsried, Germany.
Proc Natl Acad Sci U S A. 1996 Apr 30;93(9):4355-9. doi: 10.1073/pnas.93.9.4355.
ERK6, a mitogen-activated protein (MAP) kinase-related serine/threonine kinase, is highly expressed in human skeletal muscle and appears to function as a signal transducer during differentiation of myoblasts to myotubes. In transfected 293 cells, activation of the 45-kDa enzyme results in tyrosine-phosphorylated 46- and 56-kDa forms, which phosphorylate myelin basic protein. Overexpression of wild-type ERK6 or the inactive mutant Y185F has no effect on fibroblast and myoblast proliferation, but it enhances or inhibits C2C12 cell differentiation to myotubes, respectively. Our findings suggest ERK6 to be a tissue-specific, differentiation signal-transducing factor that is connected to phosphotyrosine-mediated signaling pathways distinct from those activating other members of the MAP kinase family such as LRK1 and ERK2.
ERK6是一种丝裂原活化蛋白（MAP）激酶相关的丝氨酸/苏氨酸激酶，在人类骨骼肌中高度表达，并且在成肌细胞向肌管分化过程中似乎作为信号转导分子发挥作用。在转染的293细胞中，45 kDa酶的激活导致酪氨酸磷酸化的46 kDa和56 kDa形式，它们可使髓鞘碱性蛋白磷酸化。野生型ERK6或无活性突变体Y185F的过表达对成纤维细胞和成肌细胞的增殖没有影响，但分别增强或抑制C2C12细胞向肌管的分化。我们的研究结果表明ERK6是一种组织特异性的分化信号转导因子，它与磷酸酪氨酸介导的信号通路相关，这些信号通路不同于激活MAP激酶家族其他成员（如LRK1和ERK2）的信号通路。
