Glucose-dependent insulinotropic peptide: structure of the precursor and tissue-specific expression in rat.
Glucose-dependent insulinotropic peptide: structure of the precursor and tissue-specific expression in rat.
复制标题
葡萄糖依赖性促胰岛素肽：前体结构和大鼠组织特异性表达。
DOI：
10.1073/pnas.90.5.1992
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发表时间：
1993
影响因子：
11.1
通讯作者：
Wolfe,MM
中科院分区：
文献类型：
--
作者：
Tseng,CC;Jarboe,LA;Landau,SB;Williams,EK;Wolfe,MM
葡萄糖依赖性促胰岛素肽（GIP）是一种42个氨基酸的胃肠调节肽，在葡萄糖存在下刺激胰腺β细胞分泌胰岛素。用噬斑杂交法从新生大鼠小肠cDNA文库中筛选出约7.8 × 10（5）个重组克隆，用双脱氧核苷酸链终止法鉴定了3个克隆并测序。从cDNA的核苷酸序列推导的翻译的氨基酸序列表明，大鼠GIP是由144个氨基酸的前体多肽的蛋白水解加工。成熟肽的侧翼是含有21个氨基酸的信号肽的43个氨基酸的NH 2-末端肽和59个氨基酸的COOH-末端肽。对大鼠GIP的核苷酸和氨基酸序列的分析显示，已知的人GIP肽仅有两个取代。从各种器官中提取的总RNA的高严格RNA印迹杂交分析表明，GIP基因在十二指肠和空肠中表达，在较小程度上，在回肠中表达。此外，通过RNA分析和放射免疫分析，GIP基因的表达在下颌下唾液腺观察。在十二指肠灌注20%Lipomul餐60分钟，十二指肠粘膜GIP mRNA浓度增加42.8%和48.2%，分别在30和60分钟。
Glucose-dependent insulinotropic peptide (GIP) is a 42-amino acid gastrointestinal regulatory peptide that stimulates insulin secretion from pancreatic beta cells in the presence of glucose. Approximately 7.8 x 10(5) recombinant clones of a neonatal rat intestinal cDNA library were screened by using plaque hybridization, and three clones were identified and sequenced with the dideoxynucleotide chain-termination method. The translated amino acid sequence deduced from the nucleotide sequence of the cDNA indicated that rat GIP was derived by proteolytic processing of a 144-amino acid precursor polypeptide. The mature peptide is flanked by a 43-amino acid NH2-terminal peptide that contains a 21-amino acid signal peptide and by a 59-amino acid COOH-terminal peptide. Analysis of the nucleotide and amino acid sequence of rat GIP revealed only two substitutions from the known human GIP peptide. The use of high-stringency RNA blot-hybridization analysis of total RNA extracted from various organs demonstrated expression of the GIP gene in the duodenum and jejunum and, to a lesser extent, in the ileum. In addition, expression of the GIP gene was observed in the submandibular salivary gland both by RNA analysis and RIA. In response to duodenal perfusion of a 20% Lipomul meal for 60 min, duodenal mucosal GIP mRNA concentrations increased by 42.8% and 48.2% at 30 and 60 min, respectively.