Yu Wen-Mei, Hawley Teresa S, Hawley Robert G, Qu Cheng-Kui
Department of Hematopoiesis, Jerome H Holland Laboratory for the Biomedical Sciences, American Red Cross, 15601 Crabbs Branch Way, Rockville, MD 20855, USA.
Oncogene. 2003 Sep 4;22(38):5995-6004. doi: 10.1038/sj.onc.1206846.
SHP-2 tyrosine phosphatase is highly expressed in hematopoietic cells, however, the function of SHP-2 in hematopoietic cell signaling is not well understood. Here we focus on the role of SHP-2 phosphatase in the signal transduction of interleukin (IL)-3, a cytokine involved in hematopoietic cell survival, proliferation, and differentiation. We established immortalized SHP-2(-/-) hematopoietic cell pools and showed that IL-3-induced proliferative response was diminished in SHP-2(-/-) cells. Moreover, inhibition of the catalytic activity of SHP-2 in wild-type (WT) bone marrow hematopoietic progenitor cells and Ba/F3 cells by overexpression of catalytically inactive SHP-2 mutant suppressed their differentiative and proliferative responses to IL-3, demonstrating an important positive role for SHP-2 in IL-3 signal transduction. Further biochemical analyses revealed that IL-3-induced Jak/Stat, Erk, and PI3 kinase pathways in SHP-2(-/-) cells were impaired and reintroduction of WT SHP-2 into mutant cells partially restored IL-3 signaling. Interestingly, in catalytically inactive SHP-2-overexpressing Ba/F3 cells, although IL-3-induced activation of Jak2 and Erk kinases was reduced and shortened, PI3 kinase activation remained unaltered. Taken together, these results suggest that SHP-2 tyrosine phosphatase plays multiple roles in IL-3 signal transduction, functioning in both catalytic-dependent and -independent manners in the Jak/Stat, Erk, and PI3 kinase pathways.
SHP-2 酪氨酸磷酸酶在造血细胞中高表达,然而,SHP-2 在造血细胞信号传导中的功能尚未完全明确。在此,我们聚焦于 SHP-2 磷酸酶在白细胞介素(IL)-3 信号转导中的作用,IL-3 是一种参与造血细胞存活、增殖和分化的细胞因子。我们建立了永生化的 SHP-2(-/-)造血细胞库,并发现 IL-3 诱导的增殖反应在 SHP-2(-/-)细胞中减弱。此外,通过过表达催化失活的 SHP-2 突变体抑制野生型(WT)骨髓造血祖细胞和 Ba/F3 细胞中 SHP-2 的催化活性,可抑制它们对 IL-3 的分化和增殖反应,这表明 SHP-2 在 IL-3 信号转导中具有重要的正向作用。进一步的生化分析表明,IL-3 诱导的 SHP-2(-/-)细胞中的 Jak/Stat、Erk 和 PI3 激酶途径受损,将 WT SHP-2 重新引入突变细胞可部分恢复 IL-3 信号传导。有趣的是,在过表达催化失活的 SHP-2 的 Ba/F3 细胞中,尽管 IL-3 诱导的 Jak2 和 Erk 激酶激活减少且持续时间缩短,但 PI3 激酶激活保持不变。综上所述,这些结果表明 SHP-2 酪氨酸磷酸酶在 IL-3 信号转导中发挥多种作用,在 Jak/Stat、Erk 和 PI3 激酶途径中以催化依赖和非依赖的方式发挥功能。