MAMMALIAN PANCREATIC PREPROGLUCAGON CONTAINS 3 GLUCAGON-RELATED PEPTIDES
MAMMALIAN PANCREATIC PREPROGLUCAGON CONTAINS 3 GLUCAGON-RELATED PEPTIDES
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DOI：
10.1073/pnas.80.18.5485
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发表时间：
1983-01-01
期刊：
影响因子：
--
通讯作者：
SAUNDERS, GF
中科院分区：
文献类型：
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作者：
LOPEZ, LC;FRAZIER, ML;SAUNDERS, GF
c分离了牛胰腺胰高血糖素前原的互补DNA克隆。利用人工合成的寡脱氧核苷酸探针对3100个胎牛胰腺cDNA文库进行筛选，筛选出25个推测的胰高血糖素前体细胞克隆。探针是合成的17碱基DNA低聚物的混合物，与成熟胰高血糖素的6个羧基末端氨基酸（残基24-29）相对应。其中6个克隆的限制性内切图谱表明它们代表一个单一的mRNA物种。对含有1200碱基对DNA插入的1个克隆进行初级序列分析，发现其含有胰高血糖素mRNA的全长拷贝。分析结果表明，该基因的编码序列为540个核苷酸，5‘’和3‘’非翻译区分别为90个和471个核苷酸。这个cDNA序列编码了一个20个氨基酸的信号序列，然后是一个glicentin的信号序列，glicentin是一种含有69个氨基酸的多肽，含有猪肠中发现的内部胰高血糖素片段。Glicentin之后是2个额外的胰高血糖素样肽，每个肽的两侧是激素原加工特征的成对碱性氨基酸（Lys, Arg）。这些多肽序列与胰高血糖素和其他胰高血糖素家族成员的序列具有惊人的同源性。
c[complementary]DNA clones encoding bovine pancreatic preproglucagon were isolated. A total of 25 putative preproglucagon clones were selected by screening 3100 clones of a fetal bovine pancreas cDNA library with a synthetic oligodeoxynucleotide probe. The probe was a mixture of synthetic 17-base DNA oligomers constructed to correspond to the 6 carboxyl-terminal amino acids (residues 24-29) of mature glucagon. Restriction mapping of 6 of these clones suggested that they represented a single mRNA species. Primary sequence analysis of 1 clone containing a 1200 base-pair DNA insert revealed that it contained an essentially full-length copy of glucagon mRNA. Analysis of the cDNA suggested a protein coding sequence of 540 nucleotides and 5''- and 3''-untranslated regions of 90 and 471 nucleotides, respectively. This cDNA sequence encoded a 20 amino acid signal sequence followed by one for glicentin, a 69-amino acid polypeptide containing an internal glucagon moiety that was found in porcine intestines. Glicentin is followed by 2 additional glucagon-like peptides, each flanked by paired basic amino acids (Lys, Arg) characteristics of prohormone processing. These polypeptide sequences show striking homology with those for glucagon and other members of the glucagon family of peptides.