The rat intrinsic factor gene: its 5'-upstream region and chief cell-specific transcription.
The rat intrinsic factor gene: its 5'-upstream region and chief cell-specific transcription.
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大鼠内因子基因：其 5-上游区域和主要细胞特异性转录。
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
M. Futai
中科院分区：
文献类型：
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作者：
M. Maeda;S. Asahara;T. Nishi;S. Mushiake;T. Oka;S. Shimada;T. Chiba;M. Tohyama;M. Futai
从大鼠体内克隆了含有胃内因子基因5'上游区和氨基末端阅读框的DNA片段，并测定了其核苷酸序列。 S1 作图表明转录起始位点位于第二个 TATA-box 序列的下游。在推导的序列中发现了与胃主细胞中转录的胃蛋白酶原基因相似的序列基序，表明大鼠内因子基因在这些细胞中转录。内因子及其同源蛋白转钴胺素 I 的基因显然源自共同的祖先基因，因为它们的内含子插入位置以及氨基酸残基是保守的。 Northern印迹杂交显示内因子基因在胃中转录，但在肠、肾、睾丸、脑、心脏、肝、肺或脾中检测不到。使用放射性互补RNA的原位杂交清楚地表明胃腺体中的主要转录位点是主细胞。先前使用抗体观察到各种哺乳动物中内因子蛋白表达的不同位置：在大鼠壁细胞和主细胞中、在小鼠主细胞中和在人壁细胞中。目前的结果清楚地表明，内因子 mRNA 主要存在于成年大鼠的主细胞中，与小鼠一样，这表明内因子基因的转录调控在啮齿类动物中基本相同。
A DNA segment containing the 5'-upstream region and amino terminal reading frame of the gastric intrinsic factor gene was cloned from rat and its nucleotide sequence was determined. S1 mapping demonstrated that the transcription initiation site is located downstream of the second TATA-box sequence. Similar sequence motifs to those in the pepsinogen genes transcribed in gastric chief cells were found in the deduced sequence, suggesting that the rat intrinsic factor gene is transcribed in these cells. The genes for the intrinsic factor and its homologous protein transcobalamin I were apparently derived from a common ancestoral gene, since the positions of their intron insertions as well as the amino acid residues are conserved. Northern blot hybridization showed that the gene for the intrinsic factor is transcribed in the stomach but not detectably in the intestine, kidney, testis, brain, heart, liver, lung, or spleen. In situ hybridization using radioactive complementary RNA clearly indicated that the major transcription site in gastric glands is chief cells. Different locations of expression of intrinsic factor proteins in various mammals were observed previously using antibodies: in rat parietal cells and chief cells, in mouse chief cells, and in human parietal cells. The present results clearly demonstrated the intrinsic factor mRNA mainly in chief cells of adult rats, as in mice, suggesting that transcriptional regulation of the intrinsic factor gene is essentially the same in rodents.