Identification of molecules involved in inactivation of mast cells.

鉴定参与肥大细胞失活的分子。

• 批准号: 13557040
• 负责人: KITAMURA Toshio
• 金额: $ 8.83万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13557040/
• 关键词: mast cell; NK receptor; allergy; paired Ig receptor; phosphatase; signal sequence trap; ITIMモチーフ; シグナルシークエンストラップ; 膜蛋白質; シグナル伝達

We searched for secreted and membrane proteins from cultured bone marrow-derived mouse mast cells using retrovirus-mediated signal sequence trap method SST-REX. From this screening, we identified a novel membrane protein harboring a homology with inhibitory NK receptors. This protein harbors a single immunoglobulin like domain in the extracellular domein and three or four ITIM inhibitory motifs in the intracellular domain, and was designated as LMIRl that stands for Jeukocyte-associated mono Ig receptor-l. From the data base search, we also identified LMIR-2-6 that resemble LMIR1, and isolated full-length cDNAs for these proteins. LMIRl and 3 harbors ITIM motifs in the intracellular domain, and upon ligation, they induced phosphorylation of phosphatases SHP1, SHP2, and SHIP, thereby inducing inhibitory signals. On the other hand, LMIR2, 4, 5, and 6 have short intracellular domain, and associate with activating receptors including DAP10, DAP12 and FcRg through the transmembrane domains. We have developed monoclonal antibodies against LMIR-1-6. To clarify the physiological roles of these molecules especially in the control of mast cell activation, we are now trying to identify the ligands for LMIR1 and 3, and to generate the knockout mice for LMIRI-3.

我们使用逆转录病毒介导的信号序列捕获方法 SST-REX 从培养的骨髓来源的小鼠肥大细胞中寻找分泌蛋白和膜蛋白。通过这次筛选，我们鉴定出了一种与抑制性 NK 受体具有同源性的新型膜蛋白。该蛋白质在细胞外域蛋白中具有单个免疫球蛋白样结构域，在细胞内结构域中具有三个或四个ITIM抑制基序，并且被指定为LMIR1，其代表白细胞相关单Ig受体-1。从数据库搜索中，我们还鉴定了与 LMIR1 相似的 LMIR-2-6，并分离了这些蛋白质的全长 cDNA。 LMIR1和3在胞内结构域中含有ITIM基序，并且在连接后，它们诱导磷酸酶SHP1、SHP2和SHIP的磷酸化，从而诱导抑制信号。另一方面，LMIR2、4、5和6具有短的胞内结构域，并通过跨膜结构域与包括DAP10、DAP12和FcRg在内的激活受体结合。我们开发了针对 LMIR-1-6 的单克隆抗体。为了阐明这些分子的生理作用，特别是在控制肥大细胞激活方面的作用，我们现在正在尝试鉴定 LMIR1 和 3 的配体，并生成 LMIRI-3 的敲除小鼠。

项目成果

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