An unusual inhibitory receptor - the mast cell function-associated antigen (MAFA)
An unusual inhibitory receptor - the mast cell function-associated antigen (MAFA)
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DOI：
10.1016/s0161-5890(02)00080-9
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发表时间：
2002-09-01
影响因子：
3.6
通讯作者：
Pecht, I
中科院分区：
文献类型：
--
作者：
Abramson, J;Xu, R;Pecht, I
肥大细胞功能相关抗原（MAFA）是一种II型膜糖蛋白，首次在RBL-2 H3系大鼠粘膜型肥大细胞表面发现。MAFA的胞外和胞内结构域分别含有一个C型凝集素结构域和一个基于免疫受体酪氨酸的抑制基序（ITIM）。最近发现了MAFA的人类和小鼠同源物。然而，它们也或仅由NK细胞和T细胞表达，它们在其中很可能发挥不同的作用。MAFA通过其特异性抗体mAb G63的聚集先前已显示引起这些细胞对Fc ε RI刺激的分泌应答的剂量依赖性抑制。最近的研究结果表明，MAFA的抑制作用涉及至少两种不同的酶：在PTK林恩对MAFA ITIM进行酪氨酰磷酸化后，两种磷酸酶SHIP和SHP 2在质膜上被招募到它那里，在那里它们传播抑制信号。以下是关于这种不寻常的抑制性受体及其功能活性的简要报告。(C)2002爱思唯尔科技有限公司版权所有。
The mast cell function-associated antigen (MAFA) is a type II membranal glycoprotein that was first identified on the surface of rat mucosal-type mast cells of the RBL-2H3 line. A C-type lectin domain and an immunoreceptor tyrosine-based inhibitory motif (ITIM) are located in the extracellular and intracellular domains of MAFA, respectively. Human and mouse homologues of MAFA have been discovered recently. However, they are expressed also or only by NK and T-cells, where they most probably play different roles. MAFA clustering by its specific antibody mAb G63 has been previously shown to cause a dose-dependent inhibition of the secretory response of these cells to the FcepsilonRI stimulus. More recent results established that MAFA's inhibitory action involves at least two different enzymes: Following the tyrosyl-phosphorylation of MAFA ITIM by the PTK Lyn, two phosphatases SHIP and SHP2 are recruited to it at the plasma membrane where they propagate the inhibitory signals. The following is a brief report on this unusual inhibitory receptor and its functional activities. (C) 2002 Elsevier Science Ltd. All rights reserved.