AUTHOR=Strasser Richard 

TITLE=Challenges in O-glycan engineering of plants

JOURNAL=Frontiers in Plant Science

VOLUME=3

YEAR=2012

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2012.00218

DOI=10.3389/fpls.2012.00218

ISSN=1664-462X

ABSTRACT=<p>Plants are attractive alternative expression hosts for the production of recombinant proteins. Many therapeutic proteins are glycosylated with <italic>N</italic>- and <italic>O</italic>-glycosylation being the most prevalent forms of protein glycosylation. While <italic>N</italic>-glycans have already been modified in plants toward the formation of homogenous mammalian-type glycoforms with equal or improved biological function compared to mammalian-cell culture produced glycoproteins little attention has been paid to the modification of <italic>O</italic>-linked glycans. Recently, the first step of mammalian <italic>O</italic>-glycan biosynthesis has been accomplished in plants. However, as outlined in this short review there are important issues that have to be addressed in the future. These include: (i) elimination of potentially immunogenic or allergenic carbohydrate epitopes containing arabinosides or arabinogalactans, (ii) a detailed investigation of the interplay between engineered <italic>N</italic>- and <italic>O</italic>-glycosylation pathways to avoid competition for common metabolites like UDP-GlcNAc, and (iii) a deeper understanding of signals and mechanisms for distribution of glycan processing enzymes, which is a prerequisite for complete and homogenous glycosylation of recombinant proteins.</p>