The paired Ig-like receptor PIR-B is an inhibitory receptor that recruits the protein-tyrosine phosphatase SHP-1
The paired Ig-like receptor PIR-B is an inhibitory receptor that recruits the protein-tyrosine phosphatase SHP-1
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DOI：
10.1073/pnas.95.5.2446
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发表时间：
1998-03-03
影响因子：
11.1
通讯作者：
Vivier, E
中科院分区：
文献类型：
--
作者：
Bléry, M;Kubagawa, H;Vivier, E
一个新兴的细胞表面抑制性受体家族的特征在于胞浆内免疫受体酪氨酸基序（ITIM）的存在。这些携带ITIM的抑制性受体通常与活化亚型配对，在ITIM酪氨酸磷酸化后与含Src同源结构域2的磷酸酶结合。携带ITIM的受体募集两类磷酸酶：蛋白酪氨酸磷酸酶SHP-1和SHP-2，以及多磷酸肌醇5-磷酸酶SHIP。B细胞活化的动态平衡部分由两种众所周知的携带ITIM的受体CD 22和Fc γ RIIB（IgG的低亲和力受体）控制。我们在这里描述了一种鼠ITIM携带分子PIR-B，也可以负调控B细胞活化。酪氨酸磷酸化的ITIM允许PIR-B与SHP-1结合，但不与SHIP结合。因此，PIR-B的参与启动了SHP-1依赖性抑制途径，该途径可能在调节B淋巴细胞活化中起重要作用。
An emerging family of cell surface inhibitory receptors is characterized by the presence of intracytoplasmic immunoreceptor tyrosine-based inhibition motifs (ITIM). These ITIM-bearing inhibitory receptors, which are typically paired with activating isoforms, associate with Src homology domain 2-containing phosphatases following ITIM tyrosine phosphorylation. Two categories of phosphatases are recruited by the ITIM-bearing receptors: the protein-tyrosine phosphatases, SHP-1 and SHP-2, and the polyphosphate inositol 5-phosphatase, SHIP. The dynamic equilibrium of B cell activation is partially controlled by two well known ITIM-bearing receptors, CD22 and Fc gamma RIIB, a low affinity receptor for IgG. We describe here that a murine ITIM-bearing molecule, PIR-B, can also negatively regulate B cell activation. Tyrosine-phosphorylated ITIMs allow PIR-B to associate with SHP-1 but not with SHIP. Engagement of PIR-B thereby initiates a SHP-1-dependent inhibitory pathway that may play an important role in regulating B lymphocyte activation.