MITOGENIC SIGNALING AND SUBSTRATE-SPECIFICITY OF THE FLK2/FLT3 RECEPTOR TYROSINE KINASE IN FIBROBLASTS AND INTERLEUKIN 3-DEPENDENT HEMATOPOIETIC-CELLS
MITOGENIC SIGNALING AND SUBSTRATE-SPECIFICITY OF THE FLK2/FLT3 RECEPTOR TYROSINE KINASE IN FIBROBLASTS AND INTERLEUKIN 3-DEPENDENT HEMATOPOIETIC-CELLS
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DOI：
10.1128/mcb.13.10.6572
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发表时间：
1993-10-01
影响因子：
5.3
通讯作者：
LEMISCHKA, IR
中科院分区：
文献类型：
--
作者：
DOSIL, M;WANG, SL;LEMISCHKA, IR
Flk 2/Flt 3是最近发现的一种受体酪氨酸激酶，在脑、胎盘、睾丸和原始造血细胞中表达。Flk 2/Flt 3的促有丝分裂信号传导潜力和生物化学特性已通过使用由人集落刺激因子1受体的胞外结构域和鼠Flk 2/Flt 3的跨膜和胞质结构域组成的嵌合受体进行了分析。我们证明，在转染NIH 3 T3成纤维细胞的Flk 2/Flt 3激酶的集落刺激因子1刺激导致转化的表型，并在没有其他生长因子的情况下产生完全的增殖反应。在转染的白细胞介素3（IL-3）依赖性Ba/F3淋巴样细胞中，嵌合受体的激活可以消除IL-3的需求，并维持长期增殖。我们发现，磷脂酶C-γ 1，Ras GTP酶激活蛋白，磷脂酰肌醇3 '-激酶的p85亚基，Shc，Grb 2，Vav，Fyn和Src是Flk 2/Flt 3信号转导途径的组成部分。此外，我们证明，磷脂酶C-γ 1，磷脂酰肌醇3 '-激酶的p85亚基，Shc，Grb 2和Src家族酪氨酸激酶，但不是Ras GTP酶激活蛋白，Vav，或Nck，物理上与Flk 2/Flt 3胞质结构域。观察到p85和Shc酪氨酸磷酸化的细胞类型特异性差异。Flk 2/Flt 3信号级联与内源性血小板衍生生长因子和IL-3受体的信号级联的比较分析表明，Flk 2/Flt 3显示特定的底物偏好。此外，在相同的细胞背景下，p85和Shc的酪氨酸磷酸化同样受到完全不同的生长因子的影响。
Flk2/Flt3 is a recently identified receptor tyrosine kinase expressed in brain, placenta, testis, and primitive hematopoietic cells. The mitogenic signalling potential and biochemical properties of Flk2/Flt3 have been analyzed by using a chimeric receptor composed of the extracellular domain of the human colony-stimulating factor 1 receptor and the transmembrane and cytoplasmic domains of murine Flk2/Flt3. We demonstrate that colony-stimulating factor 1 stimulation of the Flk2/Flt3 kinase in transfected NIH 3T3 fibroblasts leads to a transformed phenotype and generates a full proliferative response in the absence of other growth factors. In transfected interleukin 3 (IL-3)-dependent Ba/F3 lymphoid cells, activation of the chimeric receptor can abrogate IL-3 requirement and sustain long-term proliferation. We show that phospholipase C-gamma1, Ras GTPase-activating protein, the p85 subunit of phosphatidylinositol 3'-kinase, Shc, Grb2, Vav, Fyn, and Src are components of the Flk2/Flt3 signal transduction pathway. In addition, we demonstrate that phospholipase C-gamma1, the p85 subunit of phosphatidylinositol 3'-kinase, Shc, Grb2, and Src family tyrosine kinases, but not Ras GTPase-activating protein, Vav, or Nck, physically associate with the Flk2/Flt3 cytoplasmic domain. Cell-type-specific differences in tyrosine phosphorylation of p85 and Shc are observed. A comparative analysis of the Flk2/Flt3 signal cascade with those of the endogenous platelet-derived growth factor and IL-3 receptors indicates that Flk2/Flt3 displays specific substrate preferences. Furthermore, tyrosine phosphorylation of p85 and Shc is similarly affected by totally different growth factors in the same cellular background.