Waitz W, Loidl P
Institut für Pathologische Anatomie, Universität Innsbruck, Austria.
Oncogene. 1991 Jan;6(1):29-35.
We demonstrate the presence of a c-myc protein with an apparent molecular weight of 67 kd in the lower eukaryote Physarum polycephalum with polyclonal and monoclonal anti-c-myc-antibodies. It is shown that the amount of myc protein present in the nucleus does not fluctuate during the naturally synchronous cell cycle of Physarum. The myc protein remains firmly associated with the nuclear matrix after a variety of matrix preparation procedures. Although the level of c-myc protein is invariant during the cell cycle, the matrix-bound portion of c-myc protein is higher during S-phase as compared to G2-period. In immunoelectron microscopy the immunosignal was considerably stronger in the nuclear matrix compared with unfractionated nuclei, indicating increased accessibility of c-myc protein in nuclear scaffold structures. We show that the nuclear localization of c-myc protein changes during the cell cycle, being transiently but specifically bound to the periphery of the nuclear matrix structure during S-phase.
我们使用多克隆和单克隆抗c-myc抗体，证实在低等真核生物多头绒泡菌中存在一种表观分子量为67kd的c-myc蛋白。结果表明，在多头绒泡菌自然同步的细胞周期中，细胞核中存在的myc蛋白量不会波动。经过各种核基质制备程序后，myc蛋白仍与核基质紧密结合。尽管c-myc蛋白水平在细胞周期中不变，但与G2期相比，c-myc蛋白与核基质结合的部分在S期更高。在免疫电子显微镜下，与未分级的细胞核相比，核基质中的免疫信号要强得多，这表明c-myc蛋白在核支架结构中的可及性增加。我们表明，c-myc蛋白的核定位在细胞周期中发生变化，在S期短暂但特异性地结合到核基质结构的周边。
