N- and O-Glycosylation Pathways in the Microalgae Polyphyletic Group.

The term microalga refers to various unicellular and photosynthetic organisms representing a polyphyletic group. It gathers numerous species, which can be found in cyanobacteria (i.e., Arthrospira) as well as in distinct eukaryotic groups, such as Chlorophytes (i.e., Chlamydomonas or Chlorella) and Heterokonts (i.e., diatoms). This phylogenetic diversity results in an extraordinary variety of metabolic pathways, offering large possibilities for the production of natural compounds like pigments or lipids that can explain the ever-growing interest of industrials for these organisms since the middle of the last century. More recently, several species have received particular attention as biofactories for the production of recombinant proteins. Indeed, microalgae are easy to grow, safe and cheap making them attractive alternatives as heterologous expression systems. In this last scope of applications, the glycosylation capacity of these organisms must be considered as this post-translational modification of proteins impacts their structural and biological features. Although these mechanisms are well known in various Eukaryotes like mammals, plants or insects, only a few studies have been undertaken for the investigation of the protein glycosylation in microalgae. Recently, significant progresses have been made especially regarding protein N-glycosylation, while O-glycosylation remain poorly known. This review aims at summarizing the recent data in order to assess the state-of-the art knowledge in glycosylation processing in microalgae.

Mathieu-Rivet E ，Mati-Baouche N ，Walet-Balieu ML ，Lerouge P ，Bardor M ... -  《Frontiers in Plant Science》

Protein N-glycosylation in eukaryotic microalgae and its impact on the production of nuclear expressed biopharmaceuticals.

Mathieu-Rivet E ，Kiefer-Meyer MC ，Vanier G ，Ovide C ，Burel C ，Lerouge P ，Bardor M ... -  《Frontiers in Plant Science》

Biochemical Characterization of Human Anti-Hepatitis B Monoclonal Antibody Produced in the Microalgae Phaeodactylum tricornutum.

Vanier G ，Hempel F ，Chan P ，Rodamer M ，Vaudry D ，Maier UG ，Lerouge P ，Bardor M ... -  《PLoS One》

Perspectives for Glyco-Engineering of Recombinant Biopharmaceuticals from Microalgae.

Barolo L ，Abbriano RM ，Commault AS ，George J ，Kahlke T ，Fabris M ，Padula MP ，Lopez A ，Ralph PJ ，Pernice M ... -  《Cells》

Fine-tuning the N-glycosylation of recombinant human erythropoietin using Chlamydomonas reinhardtii mutants.

Microalgae are considered as attractive expression systems for the production of biologics. As photosynthetic unicellular organisms, they do not require costly and complex media for growing and are able to secrete proteins and perform protein glycosylation. Some biologics have been successfully produced in the green microalgae Chlamydomonas reinhardtii. However, post-translational modifications like glycosylation of these Chlamydomonas-made biologics have poorly been investigated so far. Therefore, in this study, we report on the first structural investigation of glycans linked to human erythropoietin (hEPO) expressed in a wild-type C. reinhardtii strain and mutants impaired in key Golgi glycosyltransferases. The glycoproteomic analysis of recombinant hEPO (rhEPO) expressed in the wild-type strain demonstrated that the three N-glycosylation sites are 100% glycosylated with mature N-glycans containing four to five mannose residues and carrying core xylose, core fucose and O-methyl groups. Moreover, expression in C. reinhardtii insertional mutants defective in xylosyltransferases A and B and fucosyltransferase resulted in drastic decreases of core xylosylation and core fucosylation of glycans N-linked to the rhEPOs, thus demonstrating that this strategy offers perspectives for humanizing the N-glycosylation of the Chlamydomonas-made biologics.

Leprovost S ，Plasson C ，Balieu J ，Walet-Balieu ML ，Lerouge P ，Bardor M ，Mathieu-Rivet E ... -  《-》