Atherfold P A, Norris M S, Robinson P J, Gelfand E W, Franklin R A
Department of Microbiology and Immunology, East Carolina University School of Medicine, Greenville, NC 27858, USA.
Mol Immunol. 1999 Jun;36(8):543-9. doi: 10.1016/s0161-5890(99)00076-0.
We have previously shown that stimulation of B lymphocytes with calcium ionophores lead to the phosphorylation and enzymatic activation of ERK2. We have now determined that stimulation of human primary and Jurkat T lymphocytes with ionomycin also results in the activation of ERK1 and 2 as determined by; shifts in the mobility of this enzyme on SDS PAGE gels, the binding of an antibody that recognizes only the activated form of this enzyme, and increased ability to phosphorylate myelin basic protein (MBP). Another calcium ionophore, A23187, also induced activation of ERK1 and 2 in human primary and Jurkat T lymphocytes demonstrating that this is a general effect of calcium ionophores and is not limited to ionomycin. The activation of ERK1 and 2 by calcium ionophores was rapid, transient, and occurred in a dose-dependent manner. Activation of ERK1 and 2 by increases in intracellular calcium were blocked by the MEK inhibitor PD98059. These data point to a new role for calcium fluxes in T lymphocytes.
我们之前已经表明，用钙离子载体刺激B淋巴细胞会导致ERK2的磷酸化和酶活性激活。我们现在已经确定，用离子霉素刺激人原代T淋巴细胞和Jurkat T淋巴细胞也会导致ERK1和ERK2的激活，这是通过以下方式确定的：该酶在SDS-PAGE凝胶上迁移率的变化、仅识别该酶激活形式的抗体的结合以及磷酸化髓鞘碱性蛋白（MBP）能力的增强。另一种钙离子载体A23187也能在人原代T淋巴细胞和Jurkat T淋巴细胞中诱导ERK1和ERK2的激活，这表明这是钙离子载体的普遍作用，并不局限于离子霉素。钙离子载体对ERK1和ERK2的激活迅速、短暂，且呈剂量依赖性。细胞内钙离子增加对ERK1和ERK2的激活可被MEK抑制剂PD98059阻断。这些数据表明钙离子通量在T淋巴细胞中具有新的作用。
