GP2/THP gene family of self-binding, GPI-anchored proteins forms a cluster at chromosome 7F1 region in mouse genome
GP2/THP gene family of self-binding, GPI-anchored proteins forms a cluster at chromosome 7F1 region in mouse genome
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DOI：
10.1016/j.bbrc.2004.07.197
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发表时间：
2004-09-17
影响因子：
3.1
通讯作者：
Fukuoka, S
中科院分区：
文献类型：
--
作者：
Kobayashi, K;Yanagihara, K;Fukuoka, S
我们研究了胰腺酶原颗粒膜相关蛋白 GP2（一种在酸性 pH 下表现出自我聚集的 GPI 锚定蛋白）的基因组组织，以构建基因敲除小鼠。对来自 129 个 Svj 小鼠基因组 DNA 文库的编码 GP2 的 lambda 克隆进行克隆和分析表明，GP2 基因跨度约为 16.8 kb，包含 11 个外显子。可识别的功能域包括信号序列、EGF 样基序、推定的压缩 ZP 结构域、GPI 锚附着位点和用于 GPI 锚定的跨膜序列，均编码在单独的外显子中。使用 FISH，将 GP2 基因定位到小鼠 7F1 号染色体上 THP 基因附近，THP 是一种 GP2 同源物，在肾脏厚升环 (TALH) 细胞中表达。对小鼠基因组的进一步分析表明，THP 和 GP2 基因彼此相邻，并且在 7F1 基因座中仅相距 3.5 kb。此外，THP 基因的整体结构为 16.2 kb，有 11 个外显子，与 GP2 的结构惊人地相似。这一发现表明，GP2 和 THP 基因是通过基因复制产生的，并分别进化以获得导致组织特异性表达的调控元件。比较分析表明，THP 基因的 5' 侧翼区域与 TALH 细胞特异性离子转运蛋白基因 NKCC2 的第一个内含子相似。 GP2 基因的启动子区域共享其他胰腺特异性基因中发现的顺式元件。利用该遗传信息，成功地将 GP2 无效突变引入 ES 细胞系，并在不破坏 THP 表达的情况下建立了动物模型。 (C) 2004 Elsevier Inc. 保留所有权利。
We investigated the genomic organization of pancreatic zymogen granule membrane-associated protein GP2, a GPI-anchored protein exhibiting self-aggregation at acidic pH, in order to construct a gene-knockout mouse. Cloning and analysis of lambda clones encoding GP2 from 129 Svj mouse genomic DNA libraries showed that the GP2 gene spans about 16.8 kb and includes 11 exons. Identifiable functional domains including a signal sequence, an EGF-like motif, a putative condensing ZP domain, a GPI-anchor attachment site, and a transmembrane sequence for GPI anchoring are encoded in separate exons. Using FISH, the GP2 gene was mapped to mouse chromosome 7F1 near the gene for THP, a GP2 homolog expressed in the cells of thick ascending loop of Henle (TALH) in the kidney. Further analysis of the mouse genome revealed that the THP and GP2 genes are adjacent to one another and are separated by only 3.5 kb in the 7F1 locus. Additionally, the overall structure of the THP gene, 16.2 kb with 11 exons, was strikingly similar to that of GP2. This finding suggests that the GP2 and THP genes were generated by gene duplication and evolved separately to acquire regulatory elements leading to tissue-specific expression. Comparative analysis revealed that the 5' flanking region of the THP gene is similar to the first intron of NKCC2, a TALH cell-specific ion-transporter gene. The promoter region of the GP2 gene shares cis-elements found in other pancreas-specific genes. Using this genetic information, a GP2 null mutation was successfully introduced into an ES cell line, and an animal model was established without disruption of THP expression. (C) 2004 Elsevier Inc. All rights reserved.