Interleukin 2 induces rapid phosphorylation of cellular proteins in murine T-lymphocytes

AbstractWhen quiescent murine T-lymphocyte cells were stimulated by the addition of interleukin 2 (IL-2), they reinitiated DNA synthesis after a lag period of 5 h. Under these conditions, rapid but transient phosphorylation of two cellular proteins with Mr, values of 27000 and 26000 was detected; maximal phosphorylation occurred within 10–15 min after the addition of IL-2. The protein of Mr, 27 000 contained phosphoserine, while the protein of Mr 26000 contained phosphothreonine

〓

種々の細胞増殖因子によってNa^+/H^+アンチポーターのCキナーゼによる活性化(その結果細胞質内pHが上昇する), あるいはリボゾームS6蛋白, 細胞質41K, 43K蛋白のリン酸化が急速に促進される。それらはいずれも増殖因子によってもたらされた細胞増殖促進情報の細胞核への伝達過程において不可欠の重要な役割を果たしていると考えられる。Many growth-promoting agents have been shown to activate the amiloride-sensitive Na^+/ H^+ antiporter, leading to a rapid rise in cytoplasmic pH (pH_I) of 0.1-0.3 unit; it seems very likely that protein kinase C is involved in this activation process. Phosphorylation of cellular proteins such as ribosomal protein S6,and two 43000-Mr and two 41000-Mr proteins revealed by two-dimensional polyacrylamide-gel electrophoresis, has also been commonly observed after activation of quiescent fibroblasts with a variety of growth factors. The close correlation between mitogen action and the increased phosphorylation of these proteins is consistent with the notion that phosphorylation of such a common set of specific cellular proteins in limited number might be important for some early steps of the mitogenic-signalling pathway