The human collagen beta(1-O)galactosyltransferase, GLT25D1, is a soluble endoplasmic reticulum localized protein.
The human collagen beta(1-O)galactosyltransferase, GLT25D1, is a soluble endoplasmic reticulum localized protein.
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人类胶原蛋白β（1-O）半乳糖基转移酶GLT25D1是一种可溶性内质网局部蛋白质。
DOI：
10.1186/1471-2121-11-33
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发表时间：
2010-05-14
期刊：
影响因子：
--
通讯作者：
van Leeuwen, Hans C.
中科院分区：
文献类型：
--
作者：
Liefhebber, Jolanda M. P.;Punt, Simone;Spaan, Willy J. M.;van Leeuwen, Hans C.
糖基转移酶将糖基转移到其底物上。本地化部分地定义了它们的功能。糖基转移酶25结构域1（GLT 25 D1）最近被证明对胶原和另一种众所周知的底物甘露糖结合凝集素（MBL）具有半乳糖基转移酶活性。为了更深入地了解胶原蛋白的Gly-X-Lys重复序列中赖氨酸的半乳糖基化作用，我们研究了GLT 25 D1的亚细胞定位。在人肝癌细胞系（Huh 7）中表达的GLT 25 D1的免疫荧光分析揭示了核周晶格样染色，类似于定位于内质网（ER）。使用预测程序鉴定可能的靶向信号，N-末端信号序列和C-末端ER保留信号。然后通过构建一系列表位标记形式的GLT 25 D1来研究这些信号，通过免疫荧光和蛋白质印迹法分析这些信号。与预测一致，我们的结果表明，GLT 25 D1作为可溶性蛋白被定向到ER腔并保留在那里。此外，使用两种内切糖苷酶EndoH和EndoF，我们证明了推定的双功能糖基转移酶本身是一种糖蛋白。此外，我们检查了GLT 25 D1与MBL和赖氨酰羟化酶3（LH 3，PLOD 3）的共定位，赖氨酰羟化酶3是一种能够在赖氨酸残基被糖基化之前催化其羟基化的蛋白质。我们展示了GLT 25 D1，MBL和LH 3的重叠定位模式。综上所述，我们的数据表明，半乳糖基化的胶原蛋白的可溶性GLT 25 D1发生在早期分泌途径。
Glycosyl transferases transfer glycosyl groups onto their substrate. Localization partially defines their function. Glycosyl transferase 25 domain 1 (GLT25D1) was recently shown to have galactosyltransferase activity towards collagens and another well known substrate, mannose binding lectin (MBL). To gain more insight in the role of galactosylation of lysines in the Gly-X-Lys repeats of collagenous proteins, we investigated the subcellular localization of GLT25D1. Immunofluorescence analysis of GLT25D1 expressed in the human hepatoma cell line (Huh7), revealed a perinuclear lattice like staining, resembling localization to the endoplasmic reticulum (ER). Possible targeting signals, an N-terminal signal sequence and a C-terminal ER-retention signal, were identified using prediction programs. These signals were then investigated by constructing a series of epitope-tagged forms of GLT25D1 that were analyzed by immunofluorescence and western blotting. In agreement with the predictions our results show that GLT25D1 is directed to the ER lumen as a soluble protein and retained there. Moreover, using two endoglycosidase enzymes EndoH and EndoF, we demonstrate that the putative bi-functional glycosyl transferase itself is a glycoprotein. Additionally we examined co-localization of GLT25D1 with MBL and lysyl hydroxylase 3 (LH3, PLOD3), which is a protein able to catalyze hydroxylation of lysine residues before they can be glycosylated. We demonstrate overlapping localization patterns of GLT25D1, MBL and LH3. Taken together our data indicate that galactosylation of collagenous proteins by the soluble GLT25D1 occurs in the early secretory pathway.
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影响因子：
4.4
作者：
Heise, CT;Nicholls, JR;Wallis, R
通讯作者：
Wallis, R
影响因子：
3.8
作者：
Ji, X;Olinger, GG;Spear, GT
通讯作者：
Spear, GT
影响因子：
16.8
作者：
Jinek, Martin;Chen, Ya-Wen;Conti, Elena
通讯作者：
Conti, Elena
DOI：
10.1016/j.bbrc.2003.09.031
发表时间：
2003-10-17
影响因子：
3.1
作者：
Kikuchi, N;Kwon, YD;Narimatsu, H
通讯作者：
Narimatsu, H
影响因子：
5.3
作者：
Schegg, Belinda;Huelsmeier, Andreas J.;Hennet, Thierry
通讯作者：
Hennet, Thierry