SLC35A2 deficiency reduces protein levels of core 1 β-1,3-galactosyltransferase 1 (C1GalT1) and its chaperone Cosmc and affects their subcellular localization - yet unpublished supplementary data

The upload contains raw data files used for the article "SLC35A2 deficiency reduces protein levels of core 1 β-1,3-galactosyltransferase 1 (C1GalT1) and its chaperone Cosmc and affects their subcellular localization". Article abstract Nucleotide sugar transporters (NSTs) are multitransmembrane proteins, localized in the Golgi apparatus and/or endoplasmic reticulum, which provide glycosylation enzymes with their substrates. It has been demonstrated that NSTs may form complexes with functionally related glycosyltransferases, especially in the N-glycosylation pathway. However, potential interactions of NSTs with enzymes mediating the biosynthesis of mucin-type O-glycans have not been addressed to date. Here we report that UDP-galactose transporter (UGT; SLC35A2) associates with core 1 β-1,3-galactosyltransferase 1 (C1GalT1; T-synthase). This provides the first example of an interaction between an enzyme that acts exclusively in the O-glycosylation pathway and an NST. We also found that SLC35A2 associated with the C1GalT1-specific chaperone Cosmc, and that the endogenous Cosmc was localized in both the endoplasmic reticulum and Golgi apparatus of wild-type HEK293T cells. Furthermore, in SLC35A2-deficient cells protein levels of C1GalT1 and Cosmc were decreased and their Golgi localization was less pronounced. Finally, we identified SLC35A2 as a novel molecular target for the antifungal agent itraconazole. Based on our findings we propose that NSTs may contribute to the stabilization of their interaction partners and help them to achieve target localization in the cell, most likely by facilitating their assembly into larger functional units. The Word document (Data description.docx) contains a description of each file.本上传文件包含用于论文《SLC35A2缺陷可降低核心1 β-1,3-半乳糖基转移酶1（core 1 β-1,3-galactosyltransferase 1，C1GalT1）及其伴侣蛋白Cosmc的蛋白水平并影响二者的亚细胞定位》的原始数据文件。 论文摘要 核苷酸糖转运蛋白（nucleotide sugar transporters，NSTs）是定位于高尔基体和/或内质网的多跨膜蛋白，可为糖基化酶提供其底物。已有研究表明，NSTs可与功能相关的糖基转移酶形成复合物，尤其是在N-糖基化通路中。但迄今为止，尚未有关于NSTs与介导黏蛋白型O-糖链生物合成的酶之间潜在相互作用的相关研究。本研究报道，UDP-半乳糖转运蛋白（UDP-galactose transporter，UGT；SLC35A2）可与核心1 β-1,3-半乳糖基转移酶1（core 1 β-1,3-galactosyltransferase 1，C1GalT1，又称T合酶（T-synthase））结合，这是首次报道仅在O-糖基化通路中发挥作用的酶与NST之间的相互作用。本研究还发现，SLC35A2可与C1GalT1特异性伴侣蛋白Cosmc结合，且在内源野生型HEK293T细胞中，Cosmc同时定位于内质网与高尔基体。此外，在SLC35A2缺陷细胞中，C1GalT1与Cosmc的蛋白水平均有所降低，且二者在高尔基体的定位显著性下降。最后，本研究证实SLC35A2是抗真菌药物伊曲康唑（itraconazole）的新型分子靶点。基于上述研究结果，我们提出假说：NSTs可通过促进其互作蛋白组装为更大的功能复合物，从而稳定这些互作蛋白并协助其在细胞内实现靶定位。 本配套Word文档（Data description.docx）中包含各数据文件的详细说明。