主动脉平滑肌细胞增殖周期中磷酸酪氨酸蛋白的研究

以人工合成的磷酸酪氨酸牛血清白蛋白为抗原免疫家兔,得到抗TPK 天然磷酸化底物(P-tyr-Pr)的特异性抗体。P-tyr-Pr ELISA测定结果显示:ASMC 胞浆和核内颗粒部分P-tyr-Pr 的最高含量均出现于G_1晚期(9 h),且核内P-tyr-Pr 的含量远高于胞浆。免疫组织化学显示:ASMC 中P-tyr-Pr 的总量也以G_1晚期为最高,在G_1晚期ASMC 中,P-tyr-Pr 主要分布于细胞核及其周围的胞浆中。

STUDIES ON THE PHOSPHO-TYROSINE PROTEINS DURING THE PROLIFERATION CYCLE OF CULTURED AORTIC SMOOTH MUSCLE CELLS

The dynamic change and distributionof phospho-tyrosine proteins(P-tyr-Pr)during the cell cycle of cultured rabbitaortic smooth muscle cells(ASMC)werestudied by ELISA and immunohistochemi-cal technique.The antibody which wasspecific for P-tyr-Pr was prepared by im-munizing California white rabbits withsynthesized phospho-tyrosine bovine serumalbumin,and then the IgG obtained waspurified and coupled to horseradish pero-xidase to make it ready for use in ELISA.We find that the content of particle P-tyr-Pr fluctuated in G_1 stage,both in thecytosol and in the nucleus,being the hi-ghest at late G_1 stage(9h after G_0),andthe content of particle P-tyr-Pr was muchhigher in the nucleus than in the cytosolthroughout G_1 stage.The immunohistoche-mical study,which locates the distributionof P-tyr-Pr in ASMC,also revealed thatthe nuclei were stained much darker thanthe cytosol,and the total P-tyr-Pr con-tent(including both particle and solubleP-tyr-Pr)was the highest at late G_1 stage,or higher than at G_0 and before S stage(12h after G_0).But the distribution be-fore S stage was similar to that at lateG_1 stage,and although the total contentbefore S stage was lower than at late G_1stage,it was evidently higher than thatat G_0 stage.This last finding might havesome bearing on the role of tyrosine pro-tein kinase in the events of a cell cycle.