Structure, chromosomal localization and expression of mouse genes encoding type III Reg, RegIII alpha, RegIII beta, RegIII gamma
Structure, chromosomal localization and expression of mouse genes encoding type III Reg, RegIII alpha, RegIII beta, RegIII gamma
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DOI：
10.1016/s0378-1119(96)00589-6
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发表时间：
1997-02-07
期刊：
影响因子：
3.5
通讯作者：
Okamoto, H
中科院分区：
文献类型：
--
作者：
Narushima, Y;Unno, M;Okamoto, H
Reg（再生基因）首次从大鼠再生胰岛cDNA文库中分离出来，在再生胰岛β细胞中表达。近年来，研究发现Reg及其相关基因组成了一个多基因家族，即Reg家族，根据基因编码蛋白的一级结构，Reg家族可分为I、II、III型三个亚型。在小鼠中，目前已分离到I型和II型regg基因（即RegI和RegII基因）。本研究测定了小鼠III型Reg（再生基因产物）、RegIII α、RegIII β和RegIII γ编码的cdna和基因的全核苷酸序列。RegIII α、RegIII β和RegIII γ分别编码175、175和174个氨基酸（aa）的蛋白，同源性为60-70%。这三个基因都由6个外显子和5个内含子组成。3 kb，并表现出Reg基因家族成员特有的独特结构特征。通过荧光原位杂交（fluorescence in situ hybridization， FISH）将小鼠所有的regg基因RegIII α、RegIII β、RegIII γ、RegI和RegII定位到6C染色体的相邻位点。RegIII α、RegIII β和RegIII γ在胰腺中表达弱，在肠道中表达强，而在增生性胰岛中不表达，而RegI和RegII在增生性胰岛中均表达。这些结果表明，小鼠Reg家族的基因是由一个共同的祖先基因经过多次基因复制而来，并在遗传进化过程中获得了表达和功能上的差异。
Reg (regenerating gene), first isolated from a rat regenerating islet cDNA library, is expressed in regenerating islet beta-cells. Recently, it has been revealed that Reg and Reg-related genes constitute a multigene family, Reg family, which consists of three subtypes (type I, II, III) based on the primary structures of the encoded proteins of the genes. In mouse, type I and type II Reg genes (i.e. RegI and RegII gene) have so far been isolated. In the present study, the complete nucleotide (nt) sequences of the cDNAs and genes encoding murine type III Reg (regenerating gene product), RegIII alpha, RegIII beta and RegIII gamma were determined. RegIII alpha, RegIII beta and RegIII gamma encode 175-, 175- and 174-amino acid (aa) proteins, respectively, with 60-70% homology. All three genes are composed of six exons and five introns spanning approx. 3 kb, and exhibit distinctive structural features unique for members of the Reg gene family. All the mouse Reg genes, RegIII alpha, RegIII beta, RegIII gamma, RegI and RegII, are assigned to the adjacent site of chromosome 6C by fluorescence in situ hybridization (FISH). RegIII alpha, RegIII beta and RegIII gamma were expressed weakly in pancreas, strongly in intestinal tract, but not in hyperplastic islets, whereas both RegI and RegII were expressed in hyperplastic islets. These results suggest that genes of the mouse Reg family are derived from a common ancestor gene by several gene duplications, and have obtained divergency in expression and function in the process of genetic evolution.