Identification and characterization of a second CD4-like gene in teleost fish
Identification and characterization of a second CD4-like gene in teleost fish
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DOI：
10.1016/j.molimm.2005.03.005
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发表时间：
2006-02-01
影响因子：
3.6
通讯作者：
Fischer, U
中科院分区：
文献类型：
--
作者：
Dijkstra, JM;Somamoto, T;Fischer, U
在FISH中，T细胞的细分尚未得到很好的研究，尽管已有CD8和CD4同源物的报道。这项研究描述了第二个硬骨鱼类CD4基因，CD4L-2(CD4L-2)。发现了该基因的两个彩虹鲑鱼拷贝，-2a和-2b，编码的分子具有81%的氨基酸同源性。这种2a/2b的重复可能与鲑科鱼类的四倍体祖先有关。在河豚基因组中，CD4L-2与先前报道的非常不同的类CD4基因首尾相连[Suetake，H.，Araki，K.，Suzuki，Y.，2004]。首例体外动物CD4基因的克隆、表达及鉴定。免疫遗传学56,368-374]，本文命名为CD4L-1。河豚CD4L-1和CD4L-2的侧翼基因让人想起哺乳动物中围绕CD4和LAG-3的基因。然而，无论是共线分析还是系统发育分析都不能确定鱼类CD4L基因的CD4和LAG-3同源性。CD4L-1和CD4L-2在胞浆尾部与CD4有相同的酪氨酸蛋白激酶p56(Lck)结合基序，但与LAG-3不同。Trout的CD4L-2在胸腺中的表达最高，与哺乳动物和鸡的CD4相似，而Fugu CD4L-1在脾中的表达最高。然而，CD4L-2只编码两个类免疫球蛋白结构域，而CD4L-1、CD4和LAG-3编码四个。鱼类中的类CD4基因1和2显然经历了与高等脊椎动物中的Lag-3和CD4不同的进化。(C)2005爱思唯尔有限公司。保留所有权利。
In fish, T cell subdivision is not well studied, although CD8 and CD4 homologues have been reported. This study describes a second teleost CD4-like gene, CD4-like 2 (CD4L-2). Two rainbow trout copies of this gene were found, -2a and -2b, encoding molecules sharing 81% aa identity. The 2a/2b duplication may be related to tetraploid ancestry of salmonid fishes. In the Fugu genome CD4L-2 lies head to tail with an earlier reported, very different CD4-like gene [Suetake, H., Araki, K., Suzuki, Y., 2004. Cloning, expression, and characterization of fugu CD4, the first ectothermic animal CD4. Immunogenetics 56, 368-374], which was designated CD4L-1 in the present article. The flanking genes of the Fugu CD4L-1 and CD4L-2 are reminiscent of the genes surrounding CD4 and LAG-3 in mammals. However, neither synteny nor phylogenetic analysis could decide between CD4 and LAG-3 identity for the fish CD4L genes. CD4L-1 and CD4L-2 share a tyrosine protein kinase p56(lck) binding motif in the cytoplasmic tail with CD4 but not with LAG-3. Trout CD4L-2 expression is highest in the thymus, similar to mammalian and chicken CD4, whereas Fugu CD4L-1 expression was highest in the spleen. However, CD4L-2 encodes only two IG-like domains, whereas CD4L-1, CD4 and LAG-3 encode four. The CD4-like genes 1 and 2 in fish apparently went through an evolution different from that of LAG-3 and CD4 in higher vertebrates. (c) 2005 Elsevier Ltd. All rights reserved.