Analyses of polymorphisms in the FUT2 and FUT3 and mechanism of synthesis of Lewis blood group antigens

FUT2和FUT3多态性分析及Lewis血型抗原合成机制

基本信息

批准号：
18590647
负责人：
SOEJIMA Mikiko
金额：
$ 2.57万
依托单位：
Kurume University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18590647/
关键词：
FUT2 FUT3 Lewis blood groups glycosyltransferase 細胞内局在

项目摘要

We identified 24 SNPs containing seven novel SNPs (three of them are inactivating mutations) in the coding region of the FUT2 in Ovambos, Turks, and Mongolian populations. The genetic variations observed in these populations were similar to that of neighboring ones and seemed to reflect the geographic background and history of human migration. During screening of the se^<fus>, a Sec1-FUT2-Sec1 hybrid allele was identified in a Mongolian sample. This result implies that we need to be careful in choosing PCR primers otherwise make false-positive typing of se^<fus> because of recombinant alleles, while this allele is rare. By analysis the promoter region of the FUT2, we found African-specific SNPs with high incidence that affected transcriptional activity in culture cells. It is possible that long linkage disequilibrium (LD) block containing this region in African populations and the upstream region is also under balancing selection as an independent block of coding region.To elucidate the location of the Lewis and Se enzymes that regulate the synthesis of Lewis antigens in Golgi apparatus, we constructed chimeric genes, FUT23 and FUT32 that exchanged the N-terminal cytoplasmic regions of the FUT2 and FUT3. We observed higher expression of the Le^a than that of Le^b antigens on the COS-7 transfectants of FUT23 and FUT32 comparing to which of FUT2 and FUT3. This observation suggests that the localization of two enzymes is important for the expression of the Lewis antigens and the cytoplasmic domains contain the signal of that. We are under investigation of subcellular localization of the enzymes encoded by the fusion proteins with fluorescent proteins and the variations of the coding region of the FUT3 in several human populations.

我们在奥万博人、土耳其人和蒙古人群体的 FUT2 编码区中鉴定了 24 个 SNP，其中包含 7 个新的 SNP（其中三个是失活突变）。在这些种群中观察到的遗传变异与邻近种群相似，似乎反映了人类迁徙的地理背景和历史。在筛选 se^<fus> 的过程中，在蒙古样本中鉴定出了 Sec1-FUT2-Sec1 杂交等位基因。这一结果意味着我们在选择PCR引物时需要小心，否则会因为重组等位基因而造成se^<fus>的假阳性分型，而这种等位基因很少见。通过分析FUT2的启动子区域，我们发现了非洲特有的高发生率的SNPs，这些SNPs影响了培养细胞中的转录活性。有可能非洲人群中包含该区域的长连锁不平衡（LD）区及其上游区域也作为独立的编码区区处于平衡选择之下。阐明调节Lewis合成的Lewis和Se酶的位置利用高尔基体中的抗原，我们构建了嵌合基因 FUT23 和 FUT32，它们交换了 FUT2 和 FUT3 的 N 端细胞质区域。与 FUT2 和 FUT3 相比，我们观察到 FUT23 和 FUT32 的 COS-7 转染子上 Le^a 抗原的表达高于 Le^b 抗原的表达。这一观察结果表明，两种酶的定位对于路易斯抗原的表达很重要，并且细胞质结构域包含该信号。我们正在研究荧光蛋白融合蛋白编码的酶的亚细胞定位以及几个人群中 FUT3 编码区的变异。