Miller Ira, Hatzivassiliou Georgia, Cattoretti Giorgio, Mendelsohn Cathy, Dalla-Favera Riccardo
Institute of Cancer Genetics and the Department of Pathology, Columbia University, New York, NY 10032, USA.
Blood. 2002 Apr 15;99(8):2662-9. doi: 10.1182/blood.v99.8.2662.
The IRTA1 and IRTA2 genes encode immunoglobulinlike cell surface receptors expressed in B cells and involved in chromosome 1q21 translocations in B-cell malignancy. We have now characterized and comparatively analyzed the structure and expression pattern of the entire family of IRTA genes, which includes 5 members contiguously located on chromosome 1q21. The IRTA messenger RNAs are expressed predominantly in the B-cell lineage within discrete B-cell compartments: IRTA1 is specific to the marginal zone, IRTA2 and IRTA3 are found in the germinal center light zone and in intraepithelial and interfollicular regions, and IRTA4 and IRTA5 are expressed predominantly in the mantle zone. All IRTA genes code for transmembrane receptors that are closely related to Fc receptors in their most amino-terminal extracellular domains and that possess cytoplasmic domains containing ITIM (immunotyrosine inhibition motifs)- and, possibly, ITAM (immunotyrosine activation motifs)-like motifs. These structural features suggest that the IRTA receptors may play a role in regulating activation of normal B cells and possibly in the development of neoplasia.
IRTA1和IRTA2基因编码在B细胞中表达的免疫球蛋白样细胞表面受体，并参与B细胞恶性肿瘤中的1q21染色体易位。我们现在已经对IRTA基因整个家族的结构和表达模式进行了表征和比较分析，该家族包括5个成员，它们在染色体1q21上连续定位。IRTA信使核糖核酸主要在离散B细胞区室的B细胞谱系中表达：IRTA1特异性表达于边缘区，IRTA2和IRTA3在生发中心浅区以及上皮内和滤泡间区域中发现，而IRTA4和IRTA5主要在套区表达。所有IRTA基因编码跨膜受体，这些受体在其最氨基末端的细胞外结构域中与Fc受体密切相关，并且其胞质结构域含有ITIM（免疫酪氨酸抑制基序）以及可能的ITAM（免疫酪氨酸激活基序）样基序。这些结构特征表明，IRTA受体可能在调节正常B细胞的激活中发挥作用，并可能在肿瘤形成过程中发挥作用。
