Evenhuis Jason, Bengtén Eva, Snell Cecile, Quiniou Sylvie M, Miller Norman W, Wilson Melanie
Department of Microbiology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216-4505, USA.
Immunogenetics. 2007 Aug;59(8):661-71. doi: 10.1007/s00251-007-0230-x. Epub 2007 May 30.
Mining of channel catfish (Ictalurus punctatus) expressed sequence tag databases identified seven new novel immune type receptors (IpNITRs). These differed in sequence, but not structure, from previously described IpNITR1-11. IpNITR12a, 12b, 13, and 14 encode proteins containing a single variable (V)-like immunoglobulin (Ig) domain. IpNITR12a and 13 encode a transmembrane (TM) region and cytoplasmic tail (CYT) containing immunoreceptor tyrosine inhibition motifs (ITIMs). IpNITR14 contains a TM and short CYT devoid of signaling motifs and is similar in structure to IpNITR7. IpNITR12b lacks a TM and may represent an IpNITR12a splice variant. In contrast, IpNITR15a, 15b, and 16 encode two Ig domains (V-like domain 1 and V/C2-like domain 2). IpNITR15a and 15b contain TM and CYT with ITIMs. IpNITR16 appears to be a secreted form. The first V-like domains of IpNITR12-16 (except a/b pairs) share 17-32% amino acid identity with each other and with V domains of IpNITR1-11. They therefore represent five additional IpNITR V families (defined as possessing 70% or more amino acid identity). The V/C2 domains of IpNITR15a, 15b and 16 have 94-98% amino acid identity, but share 37-50% amino acid identity with corresponding V/C2 domains found in IpNITR1-4. Phylogenetic analyses indicate IpNITR12-16 are more closely related to other teleost NITRs than to IpNITR1-11. Gene mapping indicates that IpNITRs are linked, and members of the ten known IpNITR families are interspersed. IpNITR12-16 are differentially expressed in various catfish immune-type cells and preferentially up regulated in peripheral blood leukocytes by allogeneic stimulation.
对斑点叉尾鮰（Ictalurus punctatus）表达序列标签数据库的挖掘鉴定出7种新的新型免疫型受体（IpNITRs）。这些受体在序列上与先前描述的IpNITR1 - 11不同，但结构上并无差异。IpNITR12a、12b、13和14编码的蛋白质含有单个可变（V）样免疫球蛋白（Ig）结构域。IpNITR12a和13编码一个跨膜（TM）区域和含有免疫受体酪氨酸抑制基序（ITIMs）的细胞质尾巴（CYT）。IpNITR14含有一个TM和不含信号基序的短CYT，其结构与IpNITR7相似。IpNITR12b缺乏TM，可能是IpNITR12a的剪接变体。相比之下，IpNITR15a、15b和16编码两个Ig结构域（V样结构域1和V/C2样结构域2）。IpNITR15a和15b含有带有ITIMs的TM和CYT。IpNITR16似乎是一种分泌形式。IpNITR12 - 16（除a/b对）的第一个V样结构域彼此之间以及与IpNITR1 - 11的V结构域具有17 - 32%的氨基酸同一性。因此，它们代表另外五个IpNITR V家族（定义为具有70%或更多的氨基酸同一性）。IpNITR15a、15b和16的V/C2结构域具有94 - 98%的氨基酸同一性，但与在IpNITR1 - 4中发现的相应V/C2结构域具有37 - 50%的氨基酸同一性。系统发育分析表明，IpNITR12 - 16与其他硬骨鱼NITRs的关系比与IpNITR1 - 11的关系更密切。基因定位表明IpNITRs是连锁的，并且十个已知IpNITR家族的成员相互穿插。IpNITR12 - 16在各种鲶鱼免疫型细胞中差异表达，并在同种异体刺激下在外周血白细胞中优先上调。
