Production of n-octanoyl-modified ghrelin in cultured cells requires prohormone processing protease and ghrelin O-acyltransferase, as well as n-octanoic acid.
Production of n-octanoyl-modified ghrelin in cultured cells requires prohormone processing protease and ghrelin O-acyltransferase, as well as n-octanoic acid.
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DOI：
10.1093/jb/mvp112
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发表时间：
2009-11
影响因子：
2.7
通讯作者：
Tomoko Takahashi;T. Ida;Takahiro Sato;Yoshiki Nakashima;Yuki Nakamura;A. Tsuji;M. Kojima
中科院分区：
文献类型：
--
作者：
Tomoko Takahashi;T. Ida;Takahiro Sato;Yoshiki Nakashima;Yuki Nakamura;A. Tsuji;M. Kojima
生长素释放肽最初是从大鼠胃中分离出来的，作为 GH 促分泌素受体的内源性配体。生长素释放肽的主要活性形式是由丝氨酸3残基上的正辛酸修饰的28个氨基酸肽，这种脂质修饰对于生长素释放肽的生物活性至关重要。然而，尚不清楚激素原转化酶（PC）和生长素释放肽O-酰基转移酶（GOAT）是否是培养细胞中合成酰基修饰的生长素释放肽的最低要求。通过使用加工蛋白酶和 GOAT 表达水平不同的 TT、AtT20 和 COS-7 三种培养细胞系，我们检查了 ghrelin 前体的加工模式。我们发现不仅PC1/3而且PC2和弗林蛋白酶都可以将proghrelin加工成28个氨基酸的ghrelin。此外，细胞中存在PC和GOAT，以及培养基中存在正辛酸，对于产生正辛酰生长素释放肽是必要的。
Ghrelin was originally isolated from rat stomach as an endogenous ligand for the GH secretagogue receptor. The major active form of ghrelin is a 28-amino acid peptide modified by an n-octanoic acid on the serine 3 residue, and this lipid modification is essential for the biological activity of ghrelin. However, it is not clear whether prohormone convertase (PC) and ghrelin O-acyltransferase (GOAT) are the minimal requirements for synthesis of acyl-modified ghrelin in cultured cells. By using three cultured cell lines, TT, AtT20 and COS-7, in which the expression levels of processing proteases and GOAT vary, we examined the processing patterns of ghrelin precursor. We found that not only PC1/3 but also both PC2 and furin could process proghrelin to the 28-amino acid ghrelin. Moreover, the presence of PC and GOAT in the cells, as well as n-octanoic acid in the culture medium, was necessary to produce n-octanoyl ghrelin.