GRANULOCYTE-COLONY-STIMULATING FACTOR-RECEPTOR SIGNALING INVOLVES THE FORMATION OF A 3-COMPONENT COMPLEX WITH LYN AND SYK PROTEIN-TYROSINE KINASES
GRANULOCYTE-COLONY-STIMULATING FACTOR-RECEPTOR SIGNALING INVOLVES THE FORMATION OF A 3-COMPONENT COMPLEX WITH LYN AND SYK PROTEIN-TYROSINE KINASES
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DOI：
10.1073/pnas.91.11.4683
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发表时间：
1994-05-24
影响因子：
11.1
通讯作者：
TWEARDY, DJ
中科院分区：
文献类型：
--
作者：
COREY, SJ;BURKHARDT, AL;TWEARDY, DJ
粒细胞集落刺激因子（G-CSF）是一种糖蛋白，其通过其受体的信号传导关键性地调节粒细胞前体的活力、增殖和分化以及中性粒细胞的功能。人G-CSF受体（G-CSFR）cDNA的克隆已证明与造血/细胞因子受体超家族的其他成员的序列同源性。G-CSF刺激几种类型的人和鼠骨髓细胞中磷酸酪氨酸蛋白的出现。由于该受体不具有内在的酪氨酸激酶活性，我们假设G-CSFR与细胞溶质蛋白酪氨酸激酶（PTKs）相互作用并激活PTKs。人G-CSFR免疫沉淀物的体外蛋白激酶测定证明至少有两种酪氨酸磷蛋白，pp55和pp70。我们观察到G-CSF激活了Src相关的PTK p53/p56 lyn和非Src相关的PTK p72 syk。在抗G-CSFR免疫沉淀物中回收林恩和Syk;在不存在配体的情况下检测到林恩。此外，在G-CSF刺激后，林恩与Syk共免疫沉淀。G-CSFR氨基酸序列的分析揭示了Syk的潜在受体激活基序。免疫沉淀和序列分析数据的基础上，我们提出，人类G-CSFR形成一个三组分的信号复合物与林恩和Syk。它们依次募集到G-CSFR信号复合物中，证明了两个PTK与造血/细胞因子受体超家族成员的协调参与。
Granulocyte colony-stimulating factor (G-CSF) is a glycoprotein that critically regulates the viability, proliferation, and differentiation of granulocytic precursors and the function of neutrophils by signaling through its receptor. Cloning of the human G-CSF receptor (G-CSFR) cDNA has demonstrated sequence homology with other members of the hematopoietic/cytokine receptor superfamily. G-CSF stimulates the appearance of phosphotyrosine proteins in several types of human and murine myeloid cells. Since the receptor does not possess intrinsic tyrosine kinase activity, we hypothesized that G-CSFR interacts with and activates cytosolic protein-tyrosine kinases (PTKs). In vitro protein kinase assay of human G-CSFR immunoprecipitates demonstrated at least two tyrosine phosphoproteins, pp55 and pp70. We observed that G-CSF activated p53/p56lyn, a Src-related PTK, and p72syk, a non-Src-related PTK. Lyn and Syk were recovered in anti-G-CSFR immunoprecipitates; Lyn was detected in the absence of ligand. In addition, upon G-CSF stimulation, Lyn coimmunoprecipitated with Syk. Analysis of the G-CSFR amino acid sequence revealed a potential receptor activation motif for Syk. On the basis of immunoprecipitation and sequence analysis data, we propose that the human G-CSFR forms a three-component signaling complex with Lyn and Syk. Their sequential recruitment into the G-CSFR signaling complex demonstrates the coordinated involvement of two PTKs with a member of the hematopoietic/cytokine receptor superfamily.