真核微藻因具有生产成本低、下游产物提取方便、糖基化修饰复杂等优点而成为新的很有潜力的糖蛋白药物表达系统。然而，真核微藻蛋白质的N-糖基化途径及其修饰途径中的关键酶岩藻糖转移酶（FucT）的功能尚不清楚。我们最近发现模式生物硅藻三角褐指藻（Phaeodactylum tricornutum）基因组编码3个PtFucTs，其中PtFucT1定位于反面高尔基体，生物信息学及营养盐胁迫分析显示，PtFucTs在蛋白质N-糖基化途径中的功能可能存在差异。为此，本项目拟采用亚细胞定位研究，异源表达及底物特异性分析，TALEN敲除或RNAi敲低等技术手段，结合HPLC、MALDI-TOF质谱分析，在体外、体内两个水平阐明PtFucTs在三角褐指藻蛋白质N-糖基化途径中的功能。预期成果将有助于人们全面了解微藻蛋白质的N-糖基化途径，为微藻作为生物反应器生产糖蛋白药物奠定理论基础。

Eukaryotic microalgae have become a new potential glycoprotein drugs expression system because of its low production cost, convenient extraction of downstream products, and complex glycosylation modification. However, the N-glycosylation pathway of eukaryotic microalgal proteins and the function of the key enzyme fucosyltransferase (FucT) in the modification pathway remain unknown so far. We recently found that the P. tricornutum genome encodes three putative PtFucTs, of which PtFucT1 is localized to Trans-Golgi apparatus. Bioinformatics and quantitative RT-PCR analysis indicated that the three PtFucTs may have distinct functions in the protein N-glycosylation. Therefore, this project is intended to characterize PtFucTs functions in protein N-glycosylation pathway in P. tricornutum by subcellular localization analysis, in vitro catalytic activity and substrate specificity, TALEN knockout or RNAi knockdown, HPLC and MALDI-TOF MS analysis techniques. It is expected that the results will give a better insight and understanding into the N-glycosylation pathway of microalgal proteins, and lay a theoretical foundation for producing glycoprotein drugs by using microalgae as bioreactor.