Hilton C J, Berridge M V
Malaghan Institute of Medical Research, Wellington School of Medicine, New Zealand.
Growth Factors. 1995;12(4):263-76. doi: 10.3109/08977199509028965.
Recent studies have suggested that the membrane proximal region of the cytoplasmic domain of the erythropoietin receptor and other members of the cytokine receptor superfamily may be required for signal transduction. Expression of several deletion mutants of the erythropoietin receptor in Ba/F3 cells showed that a region with homology to the interleukin-2 receptor beta-chain which includes Box 2 is not essential for erythropoietin-dependent cell proliferation. However, a region between Box 1 and Box 2 contains essential residues for proliferative response. Expression of mutant receptors was confirmed by reverse transcriptase-PCR analysis and by Western blotting, which also showed no evidence for expression of endogenous wild-type receptor. These findings are in direct conflict with previously reported mutagenesis studies of the erythropoietin receptor suggesting that mitogenesis may be channelled through more than one pathway depending on the complement of signaling molecules expressed in the cell.
最近的研究表明，促红细胞生成素受体胞质结构域的膜近端区域以及细胞因子受体超家族的其他成员可能是信号转导所必需的。在Ba/F3细胞中促红细胞生成素受体的几种缺失突变体的表达表明，与白细胞介素-2受体β链具有同源性的一个区域（包括Box 2）对于促红细胞生成素依赖的细胞增殖并非必需。然而，Box 1和Box 2之间的一个区域包含增殖反应的必需残基。通过逆转录酶-PCR分析和蛋白质免疫印迹证实了突变受体的表达，蛋白质免疫印迹也未显示内源性野生型受体表达的证据。这些发现与先前报道的促红细胞生成素受体诱变研究直接冲突，表明有丝分裂可能通过不止一条途径进行，这取决于细胞中表达的信号分子的互补情况。
