Moss D, Powell L W, Arosio P, Halliday J W
Liver Unit, Queensland Institute of Medical Research, Bancroft Centre, Herston, Australia.
J Lab Clin Med. 1992 Aug;120(2):239-43.
We have previously demonstrated the presence of receptors specific for human recombinant H ferritin (HrHF) on human T lymphoid cells (MOLT-4), and changes in receptor number and binding affinity with growth and cell cycling have now been examined. Specific binding of HrHF was maximal in MOLT-4 cells harvested during exponential growth with the cells in the DNA synthesis phase of the cell cycle. Specific binding decreased progressively to the plateau phase of growth with the cells in the resting phase of the cell cycle. Scatchard analysis of the competitive binding data for HrHF demonstrated that this decrease in binding was associated with a reduction in receptor number, from 42,140 per cell to 10,306 per cell. Receptor binding affinity increased only minimally over this period, from 7.1 x 10(7) L/mol to 14.9 x 10(7) L/mol. These results indicate that growth- and cell cycle-induced changes in H-ferritin receptor expression are primarily associated with changes in receptor number rather than receptor binding affinity. The present study demonstrates that the expression of this receptor is associated with the proliferative status of the cell and suggests that the H-ferritin receptor may mediate the putative regulatory role of H-ferritin.
我们之前已证实在人T淋巴细胞（MOLT-4）上存在对人重组H铁蛋白（HrHF）特异的受体，现在已检测了受体数量以及与生长和细胞周期相关的结合亲和力的变化。在指数生长期收获的处于细胞周期DNA合成期的MOLT-4细胞中，HrHF的特异性结合最大。随着细胞进入细胞周期的静止期并进入生长的平台期，特异性结合逐渐降低。对HrHF竞争性结合数据的Scatchard分析表明，这种结合的降低与受体数量的减少有关，从每个细胞42,140个降至每个细胞10,306个。在此期间，受体结合亲和力仅略有增加，从7.1×10⁷L/mol增至14.9×10⁷L/mol。这些结果表明，生长和细胞周期诱导的H铁蛋白受体表达变化主要与受体数量的变化有关，而非受体结合亲和力的变化。本研究表明该受体的表达与细胞的增殖状态相关，并提示H铁蛋白受体可能介导H铁蛋白的假定调节作用。
