Molecular basis of recognition by the glycoprotein hormone-specific N-acetylgalactosamine-transferase.
Molecular basis of recognition by the glycoprotein hormone-specific N-acetylgalactosamine-transferase.
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糖蛋白激素特异性 N-乙酰半乳糖胺转移酶识别的分子基础。
DOI：
10.1073/pnas.89.1.329
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发表时间：
1992
影响因子：
11.1
通讯作者：
Baenziger,JU
中科院分区：
文献类型：
--
作者：
Smith,PL;Baenziger,JU
促黄体生成素（LH）带有以独特序列SO 4 -4GalNAc β 1-4GlcNAc β 1- 2 Man α终止的天冬酰胺连接的寡糖，而促卵泡素（FSH）带有主要以序列Sia α-Gal β 1-4GlcNAc β 1- 2 Man α终止的寡糖，其中Sia是唾液酸。我们先前鉴定了一种糖蛋白激素特异性N-乙酰半乳糖胺转移酶（GalNAc-转移酶），其识别存在于人绒毛膜促性腺激素和LH的共同糖蛋白激素α亚基和β亚基上的肽识别标记，但不识别FSH的β亚基上的肽识别标记。我们现在已经确定了一个氨基酸序列基序，Pro-Leu-Arg，这是必不可少的识别GalNAc-转移酶。该三肽序列存在于LH和人绒毛膜促性腺激素α亚基和β亚基上糖基化天冬酰胺氨基末端侧的6-9个残基上，但不存在于FSH的β亚基上。该基序的存在解释了LH和FSH寡糖结构的差异。含有该识别基序的其他蛋白质已被鉴定，并确定其具有与糖蛋白激素相同结构的硫酸化寡糖，表明这些结构不限于糖蛋白激素。
Lutropin (LH) bears asparagine-linked oligosaccharides terminating with the unique sequence SO4-4GalNAc beta 1-4GlcNAc beta 1-2Man alpha, whereas follitropin (FSH) bears oligosaccharides terminating predominantly with the sequence Sia alpha-Gal beta 1-4GlcNAc beta 1-2Man alpha, where Sia is sialic acid. We previously identified a glycoprotein-hormone-specific N-acetylgalactosamine-transferase (GalNAc-transferase) that recognizes a peptide-recognition marker(s) present on the common glycoprotein hormone alpha subunit and beta subunits of human chorionic gonadotropin and LH but not on the beta subunit of FSH. We have now identified an amino acid sequence motif, Pro-Leu-Arg, that is essential for recognition by the GalNAc-transferase. This tripeptide sequence is found 6-9 residues on the amino-terminal side of a glycosylated asparagine on the alpha subunit and beta subunits of LH and human chorionic gonadotropin but is not present on the beta subunit of FSH. The presence of this motif accounts for the differences in LH and FSH oligosaccharide structures. Additional proteins containing this recognition motif have been identified and were determined to bear sulfated oligosaccharides with the same structures as those on the glycoprotein hormones, indicating that these structures are not restricted to the glycoprotein hormones.