The chicken leukocyte receptor complex:: A highly diverse multigene family encoding at least six structurally distinct receptor types
The chicken leukocyte receptor complex:: A highly diverse multigene family encoding at least six structurally distinct receptor types
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DOI：
10.4049/jimmunol.175.1.385
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发表时间：
2005-07-01
影响因子：
4.4
通讯作者：
Göbel, TW
中科院分区：
文献类型：
--
作者：
Viertlboeck, BC;Habermann, FA;Göbel, TW
鸡igg样受体（CHIR）被描述为两个含有抑制基序的长细胞质尾部的Ig结构域分子。在这项研究中，我们证明了CHIR形成了一个大家族，多个成员在成员之间表现出很大的序列变异性，并且在跨膜和细胞质段的结构域组织和性质上也有很大的多样性。我们描述了各种新的受体类型与基序指示抑制，激活，或两者的功能。除了具有两个ITIM的抑制受体外，还分离了具有单个免疫受体酪氨酸基开关基序或缺乏细胞质结构域的受体。激活具有短胞质结构域和跨膜精氨酸与新鉴定的鸡Fc组装的受体是RI γ链的一个元件。三种双功能受体类型的特征是由一个或两个c2型igg样结构域，一个带正电荷残基的跨膜区域和细胞质基序（如ITIM，基于免疫受体酪氨酸的开关基序和YXXM）的组合组成。RT-PCR显示个体CHIR有不同的表达模式。所有受体类型共享保守的基因组结构，并且在单个Ig结构域受体中，假外显子取代了第二个Ig外显子。特异Ig1结构域探针的Southern blot分析表明存在一个大的多基因家族。从单个动物的Ig1结构域的103个序列中，获得了41个独特的序列，这些序列在受限的Ig区域内显示出广泛的变异性。荧光原位杂交将CHIR基因簇定位在微染色体31上，并鉴定该区域与人类白细胞受体复合体同源。
The chicken Ig-like receptors (CHIR) have been described as two Ig domain molecules with long cytoplasmic tails containing inhibitory motifs. In this study, we demonstrate that CHIR form a large family, with multiple members showing great sequence variability among members as well as a great diversity in domain organization and properties of the transmembrane and cytoplasmic segments. We characterize various novel receptor types with motifs indicative of inhibitory, activating, or both functions. In addition to the inhibitory receptors with two ITIM, receptors with a single immunoreceptor tyrosine-based switch motif or receptors lacking a cytoplasmic domain were isolated. Activating receptors with a short cytoplasmic domain and a transmembrane arginine assembled with the newly identified chicken Fc is an element of RI gamma chain. Three bifunctional receptor types were characterized composed of one or two C2-type Ig-like domains, a transmembrane region with a positively charged residue and combinations of cytoplasmic motifs such as ITIM, immunoreceptor tyrosine-based switch motif, and YXXM. RT-PCR revealed distinct expression patterns of individual CHIR. All receptor types shared a conserved genomic architecture, and in single Ig domain receptors a pseudoexon replaced the second Ig exon. Southern blot analyses with probes specific for the Ig1 domain were indicative of a large multigene family. Of 103 sequences from the Ig1 domain of a single animal, 41 unique sequences were obtained that displayed extensive variability within restricted Ig regions. Fluorescence in situ hybridization localized the CHIR gene cluster to microchromosome 31 and identified this region as orthologous to the human leukocyte receptor complex.