Davis R S, Wang Y H, Kubagawa H, Cooper M D
Divisions of Hematology/Oncology, Department of Medicine, University of Alabama, Birmingham 35294-3300, USA.
Proc Natl Acad Sci U S A. 2001 Aug 14;98(17):9772-7. doi: 10.1073/pnas.171308498. Epub 2001 Aug 7.
Investigation of human genome sequences with a consensus sequence derived from receptors for the Fc region of Igs (FcR) led to the identification of a subfamily of five Ig superfamily members that we term the Fc receptor homologs (FcRHs). The closely linked FcRH genes are located in a chromosome 1q21 region in the midst of previously recognized FcR genes. This report focuses on the FcRH1, FcRH2, and FcRH3 members of this gene family. Their cDNAs encode type I transmembrane glycoproteins with 3-6 Ig-like extracellular domains and cytoplasmic domains containing consensus immunoreceptor tyrosine-based activating and/or inhibitory signaling motifs. The five FcRH genes are structurally related, and their protein products share 28-60% extracellular identity with each other. They also share 15-31% identity with their closest FcR relatives. The FcRH genes are expressed primarily, although not exclusively, by mature B lineage cells. Their conserved structural features, patterns of cellular expression, and the inhibitory and activating signaling potential of their transmembrane protein products suggest that the members of this FcRH multigene family may serve important regulatory roles in normal and neoplastic B cell development.
利用源自免疫球蛋白（Ig）Fc区受体（FcR）的共有序列对人类基因组序列进行研究，从而鉴定出一个由五个Ig超家族成员组成的亚家族，我们将其称为Fc受体同源物（FcRHs）。紧密连锁的FcRH基因位于1号染色体1q21区域，处于先前已识别的FcR基因中间。本报告聚焦于该基因家族的FcRH1、FcRH2和FcRH3成员。它们的cDNA编码I型跨膜糖蛋白，具有3至6个Ig样细胞外结构域以及包含共有免疫受体酪氨酸激活和/或抑制信号基序的细胞质结构域。这五个FcRH基因在结构上相关，它们的蛋白质产物彼此之间细胞外区域的同源性为28%至60%。它们与其最接近的FcR亲属也有15%至31%的同源性。FcRH基因主要（尽管并非唯一）由成熟B淋巴细胞系细胞表达。它们保守的结构特征、细胞表达模式以及跨膜蛋白产物的抑制和激活信号潜力表明，这个FcRH多基因家族的成员可能在正常和肿瘤性B细胞发育中发挥重要的调节作用。
