As plant cells are capable of complex N-glycosylation they are a valid expression system to produce safe and correctly glycosylated human proteins. To modify plant glycosylation patterns towards fully human patterns, the plant glycosylation machinery requires substitution of a series of plant enzymes with human ones. Here we show that the mammalian glycosylation enzymes B4GALT1, ST6GAL, GNTIV and GNTV can be expressed in plant cells, and localise to specific cisternae of the Golgi body. Only ST6GAL and GNTV localise in the medial/trans-Golgi but fusion of a sialyltransferase-derived N-terminal signal peptide is capable of targeting B4GALT1 to the medial/trans-Golgi. As a proof of concept for human therapeutic enzyme production in plant cells, Lysosomal Acid Lipase (LAL) was expressed in tobacco leaf cells. Here LAL was shown to localise to medial/trans-Golgi cisternae. Protein expression of human LAL was enhanced by removal of an endogenous signal peptide associated with mammalian intracellular targeting that possessed no functional role in the therapeutic efficacy of LAL.
Permanent link to this resource: https://doi.org/10.24384/chmz-0675
McGinness, Alastair
Supervisors: Kriechbaumer, Verena; Evans, David; Gervais, David
Department of Biological and Medical SciencesFaculty of Health and Life Sciences
Year: 2020
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