Erythropoietin rapidly induces tyrosine phosphorylation in the human erythropoietin-dependent cell line, UT-7.
Erythropoietin rapidly induces tyrosine phosphorylation in the human erythropoietin-dependent cell line, UT-7.
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DOI：
10.1182/blood.v80.1.53.bloodjournal80153
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发表时间：
1992-07
期刊：
影响因子：
20.3
通讯作者：
Norio Komatsu;John W. Adamson;Kyohei Yamamoto;Daniel Altschuler;M. Torti;Riccardo Marzocchini;E. Lapetina
中科院分区：
文献类型：
--
作者：
Norio Komatsu;John W. Adamson;Kyohei Yamamoto;Daniel Altschuler;M. Torti;Riccardo Marzocchini;E. Lapetina
UT-7是一种人巨核细胞系，能够在白细胞介素3、粒细胞-巨噬细胞集落刺激因子或促红细胞生成素(EPO)中生长(癌症资源51：341,1991)。我们利用该细胞系和一个EPO依赖的亚细胞系(UT-7/EPO)研究了EPO诱导的早期信号转导事件。当UT-7细胞暴露于EPO时，观察到几种蛋白质(其分子量相当于p85、p110和p145)的酪氨酸磷酸化。蛋白质的磷酸化以剂量和时间依赖的方式发生。P85蛋白在30秒内磷酸化酪氨酸含量显著增加，1分钟时达到最大磷酸化水平。随后观察到p110和p145的酪氨酸磷酸化，1分钟开始，5分钟达到平台期。此后，这三种蛋白质的磷酸化程度逐渐降低。此外，在UT-7/EPO细胞中，EPO诱导了其他蛋白质的酪氨酸磷酸化，这在EPO诱导的UT-7细胞中没有观察到。诱导酪氨酸磷酸化所需的EPO浓度与刺激细胞生长所需的浓度范围相同。通过鸟苷二磷酸与鸟苷三磷酸的交换，EPO也能激活p21ras。这些数据表明，酪氨酸磷酸化和P21ras激活是EPO诱导的有丝分裂途径中的早期信号。
UT-7 is a human megakaryoblastic cell line capable of growing in interleukin-3, granulocyte-macrophage colony-stimulating factor, or erythropoietin (Epo) (Cancer Res 51:341, 1991). We used this cell line and a selected Epo-dependent subcell line (UT-7/Epo) to study the early signal transduction events induced by Epo. When UT-7 cells were exposed to Epo, tyrosine phosphorylation of several proteins (with molecular weight equivalent to that of p85, p110, and p145) was observed. Protein phosphorylation occurred in both a dose- and time-dependent manner. p85 showed a marked increase in phosphotyrosine content within 30 seconds; maximal phosphorylation was observed at 1 minute. Subsequently, tyrosine phosphorylation of p110 and p145 was observed, beginning at 1 minute and reaching plateau at 5 minutes. The degree of phosphorylation of these three proteins gradually decreased thereafter. In addition, in UT-7/Epo cells, Epo induced tyrosine phosphorylation of other proteins that were not observed in Epo-induced UT-7 cells. The concentration of Epo required to induce tyrosine phosphorylation was in the same range of concentration required to stimulate cell growth. Epo was also able to activate p21ras as measured by exchange of guanosine diphosphate for guanosine triphosphate. These data show that tyrosine phosphorylation and P21ras activation are early signals in the Epo-induced mitogenic pathway.