SHP-1 regulation of p62DOK tyrosine phosphorylation in macrophages
SHP-1 regulation of p62DOK tyrosine phosphorylation in macrophages
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DOI：
10.1074/jbc.274.50.35855
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发表时间：
1999-12-10
影响因子：
4.8
通讯作者：
Stanley, ER
中科院分区：
文献类型：
--
作者：
Berg, KL;Siminovitch, KA;Stanley, ER
SHP-1在造血细胞信号传导的调节中起关键作用。为了确定SHP-1对集落刺激因子-1（CSF-1）介导的存活和增殖信号传导的影响，我们比较了野生型和SHP-1缺陷型Motheaten（me/me）小鼠的原代骨髓巨噬细胞（BMM）的CSF-1反应。CSF-1诱导的蛋白酪氨酸磷酸化水平在野生型和me/me BMM中相似，除了me/me巨噬细胞中62-kDa磷蛋白（pp 62）的组成性过度磷酸化。pp 62被鉴定为RASGAP相关p62（DOK），并且被证明是CSF-1处理的BMM中主要的CSF-1 R相关酪氨酸磷酸化蛋白，发现p62 DOK与BMM和293 T细胞中的SHP-1组成性相关，共表达p62（dok）和野生型或催化惰性SHP-1（SHP-1 C453 S）。在两种细胞类型中，SHP-1与p62 DOK的相互作用独立于p62（DOK）酪氨酸磷酸化而发生，但在远Western分析中，只有酪氨酸磷酸化的p62 DOK被SHP-1 C4535结合。这些研究结果表明SHP-1和p62 DOK的组成性关联是构象依赖性的或间接的，以及SHP-1催化结构域与酪氨酸磷酸化的p62（DOK）的直接的、可诱导的关联。P62（DOK）过度磷酸化与CSF-1诱导的RAS信号传导或增殖改变无关。然而，野生型巨噬细胞在CSF-1去除后经历细胞死亡，而me/me巨噬细胞在生长因子不存在下表现出延长的存活。因此，p62（DOK）是SHP-1的主要底物，其酪氨酸磷酸化与巨噬细胞中生长因子非依赖性存活相关。
SHP-1 plays key roles in the modulation of hematopoietic cell signaling. To ascertain the impact of SHP-1 on colony-stimulating factor-1 (CSF-1)-mediated survival and proliferative signaling, we compared the CSF-1 responses of primary bone marrow macrophages (BMM) from wild-type and SHP-1-deficient motheaten (me/me) mice. CSF-1-induced protein tyrosine phosphorylation levels were similar in wild-type and me/me BMM, except for the constitutive hyperphosphoryIation of a 62-kDa phosphoprotein (pp62) in me/me macrophages. pp62 was identified as the RASGAP-associated p62(DOK) and was shown to be the major CSF-1R-associated tyrosine-phosphorylated protein in CSF-1-treated BMM, p62DOK was found to be constitutively associated with SHP-1 in BMM and in 293T cells, co-expressing p62(dok) and either wild-type or catalytically inert SHP-1 (SHP-1 C453S). In both cell types, the interaction of SHP-1 with p62DOK occurred independently of p62(DOK) tyrosine phosphorylation, but only the tyrosine-phosphorylated p62DOK was bound by SHP-1 C4535 in a far Western analysis. These findings suggest a constitutive association of SHP-1 and p62DOK that is either conformation-dependent or indirect as well as a direct, inducible association of the SHP-1 catalytic domain with tyrosine-phosphorylated p62(DOK). P62(DOK) hyperphosphorylation is not associated with altered CSF-1-induced RAS signaling or proliferation. However, whereas wild-type macrophages undergo cell death following CSF-1 removal, me/me macrophages exhibit prolonged survival in the absence of growth factor. Thus, p62(DOK) is a major SHP-1 substrate whose tyrosine phosphorylation correlates with growth factor-independent survival in macrophages.