人苯乙醇胺N-甲基转移酶基因的结构：存在两种具有不同转录起始位点的mRNA

Structure of human phenylethanolamine n-methyltransferase gene: existence of two types of mRNA with different transcription initiation sites.

作者信息

Sasaoka T, Kaneda N, Kurosawa Y, Fujita K, Nagatsu T

机构信息

Department of Biochemistry, Nagoya University School of Medicine, Nagoya 466, Japan.

出版信息

Neurochem Int. 1989;15(4):555-65. doi: 10.1016/0197-0186(89)90176-9.

DOI:10.1016/0197-0186(89)90176-9

PMID:20504532

Abstract

The chromosomal gene for human phenylethanolamine N-methyltransferase (PNMT; EC 2.1.1.28) was isolated from a human genomic library using a cloned human PNMT cDNA as a probe, and the nucleotide sequence was determined. PNMT is encoded in a single gene which consists of three exons. We observed newly the presence of minor PNMT mRNA (type B) besides the major mRNA (type A) as reported previously (Kaneda et al., J. Biol. Chem. 263, 7672-7677, 1988) by Northern hybridization. Type B mRNA carries an approximately 700 nucleotide-long untranslated region in the 5? terminus. This suggests that two types of mRNA are produced from a single gene through the use of two alternative promoters. A TATA-like sequence locates 30 base pair upstream from the cap site of type A mRNA. Upstream of the cap site, there are several sequences resembling Spl binding sites and glucocorticoid responsive elements, with the latter also found in the first intron.

摘要

利用克隆的人苯乙醇胺N-甲基转移酶（PNMT；EC 2.1.1.28）cDNA作为探针，从人基因组文库中分离出人类PNMT的染色体基因，并测定了其核苷酸序列。PNMT由一个包含三个外显子的单一基因编码。通过Northern杂交，我们如之前报道（Kaneda等人，《生物化学杂志》263, 7672 - 7677, 1988）那样，新观察到除了主要mRNA（A型）之外还存在次要的PNMT mRNA（B型）。B型mRNA在5′末端带有一个约700个核苷酸长的非翻译区。这表明通过使用两个替代启动子，从单个基因产生了两种类型的mRNA。一个类似TATA的序列位于A型mRNA帽位点上游30个碱基对处。在帽位点上游，有几个类似于Spl结合位点和糖皮质激素反应元件的序列，后者也存在于第一个内含子中。