Appel A, Kracht M, Petersen K, Resch K, Szamel M
Institute of Molecular Pharmacology, Medical School Hannover, Germany.
Eur Cytokine Netw. 1996 Dec;7(4):775-84.
Results of this study document a biphasic activation of protein kinases of the MAP kinase cascade-MEK and MAP kinases-upon interleukin-1 stimulation in human HeLa cells. The specific activities of both MEK and MAP kinases were increased within 1 min, declined rapidly to control levels and increased again after 15 min of interleukin-1 stimulation. Inhibition by okadaic acid of serine/threonine specific phosphatases resulted in a marked increase in interleukin-1 stimulated MEK and MAP kinase activities. Elevation by interleukin-1 of the specific activities of MEK and MAP kinases correlated with suppression of serine/threonine phosphatases in the late phase of stimulation. The data indicate, that enhanced phosphorylation of cellular proteins by enzymes of the MAP kinase cascade might represent a fine balance between activated protein kinases and repressed phosphoprotein phosphatase 2A in interleukin-1 stimulated HeLa cells.
本研究结果表明，在人宫颈癌细胞系HeLa细胞中，白细胞介素-1刺激后丝裂原活化蛋白激酶（MAPK）级联反应中的蛋白激酶——MEK和MAPK会出现双相激活。MEK和MAPK的比活性在1分钟内升高，迅速下降至对照水平，并在白细胞介素-1刺激15分钟后再次升高。冈田酸对丝氨酸/苏氨酸特异性磷酸酶的抑制导致白细胞介素-1刺激的MEK和MAPK活性显著增加。白细胞介素-1引起的MEK和MAPK比活性升高与刺激后期丝氨酸/苏氨酸磷酸酶的抑制相关。数据表明，在白细胞介素-1刺激的HeLa细胞中，MAPK级联反应中的酶对细胞蛋白的磷酸化增强可能代表了活化蛋白激酶和受抑制的蛋白磷酸酶2A之间的精细平衡。
