Facchimi A, Astaldi G C, Cocco L, Wisermans P, Manzoli G A, Astaldi A
J Immunol. 1979 Oct;123(4):1577-85.
Previously, it has been shown that a human thymus-dependent serum factor (SF), isolated from peripheral blood and acting on precursors of mature T lymphocytes, induces an increase in the synthesis of cyclic AMP and proteins in thymocytes. We have now investigated the action of SF on the incorporation of 3H-leucine and 32P-orthophosphate into nuclear proteins of thymocytes after 15 to 240 min of culture. SF induced a rapid increase in the synthesis and phosphorylation of nuclear proteins, especially in the phosphorylated nonhistone chromatin proteins (P-NHCP). Electrophoretic patterns in polyacrylamide gels of the P-NHCP fractions, extracted from the chromatin of the stimulated cells, showed that proteins with m.w. higher than 50 x 10(3) were synthesized to a larger extent as compared with unstimulated cells. These data suggest that SF acts specifically on the synthesis of P-NHCP and may in this way control DNA-template activity.
以前的研究表明，从外周血中分离出的一种依赖人胸腺的血清因子（SF），作用于成熟T淋巴细胞的前体细胞，可诱导胸腺细胞中环磷酸腺苷（cAMP）和蛋白质合成增加。我们现在研究了在培养15至240分钟后，SF对3H-亮氨酸和32P-正磷酸盐掺入胸腺细胞核蛋白的作用。SF诱导核蛋白的合成和磷酸化迅速增加，尤其是在磷酸化的非组蛋白染色质蛋白（P-NHCP）中。从受刺激细胞的染色质中提取的P-NHCP组分在聚丙烯酰胺凝胶中的电泳图谱显示，与未受刺激的细胞相比，分子量高于50×10³的蛋白质合成量更大。这些数据表明，SF特异性作用于P-NHCP的合成，并可能以此方式控制DNA模板活性。
