title: Production of α-L-iduronidase in maize for the potential treatment of a human lysosomal storage disease.
abstract: Lysosomal storage diseases are a class of over 70 rare genetic diseases that are amenable to enzyme replacement therapy. Towards developing a plant-based enzyme replacement therapeutic for the lysosomal storage disease mucopolysaccharidosis I, here we expressed α-L-iduronidase in the endosperm of maize seeds by a previously uncharacterized mRNA-targeting-based mechanism. Immunolocalization, cellular fractionation and in situ RT-PCR demonstrate that the α-L-iduronidase protein and mRNA are targeted to endoplasmic reticulum (ER)-derived protein bodies and to protein body-ER regions, respectively, using regulatory (5'- and 3'-UTR) and signal-peptide coding sequences from the γ-zein gene. The maize α-L-iduronidase exhibits high activity, contains high-mannose N-glycans and is amenable to in vitro phosphorylation. This mRNA-based strategy is of widespread importance as plant N-glycan maturation is controlled and the therapeutic protein is generated in a native form. For our target enzyme, the N-glycan structures are appropriate for downstream processing, a prerequisite for its potential as a therapeutic protein.
authors.affiliation: Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada.
authors.forename: Xu
authors.initials: X
authors.lastname: He
authors.forename: Thomas
authors.initials: T
authors.lastname: Haselhorst
authors.forename: Mark
authors.initials: M
authors.lastname: von Itzstein
authors.forename: Daniel
authors.initials: D
authors.lastname: Kolarich
authors.forename: Nicolle H
authors.initials: NH
authors.lastname: Packer
authors.forename: Tracey M
authors.initials: TM
authors.lastname: Gloster
authors.forename: David J
authors.initials: DJ
authors.lastname: Vocadlo
authors.forename: Lorne A
authors.initials: LA
authors.lastname: Clarke
authors.forename: Yi
authors.initials: Y
authors.lastname: Qian
authors.forename: Allison R
authors.initials: AR
authors.lastname: Kermode
mesh_terms: D006801:Humans; D007068:Iduronidase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000627:therapeutic use*; D016464:Lysosomal Storage Diseases / Q000188:drug therapy*; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism; D003313:Zea mays / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism*
chemical_list: D011134:Polysaccharides; D007068:Iduronidase