The nucleocytosolic O-fucosyltransferase SPINDLY affects protein expression and virulence in Toxoplasma gondii
| Autor: | Giulia Bandini, Christopher M. West, Hanke van der Wel, John Samuelson, Carolina Agop-Nersesian, Hyun W. Kim, Msano Mandalasi |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
0301 basic medicine
IDR intrinsically disorder region Mutant Protozoan Proteins structured illumination microscopy Biochemistry TgGMD Toxoplasma gondii GDP-mannose 4 6-dehydratase Mice chemistry.chemical_compound CAZy Carbohydrate Active EnZyme Cytosol TgSPY-3TPRs TgSPY with three C-terminal TPRs O-Fuc O-linked fucose Nuclear pore GT41 glycosyltransferase family 41 SIM structured illumination microscopy Regulation of gene expression TPR tetratricopeptide repeat Virulence Me-αFuc α-methyl fucopyranoside Fucosyltransferases HFF human foreskin fibroblast Cell biology Tetratricopeptide protein stability Toxoplasma TgGPN Toxoplasma gondii GPN-loop GTPase Research Article Fucosyltransferase Glycosylation glycosylation Toxoplasma gondii NPC nuclear pore complex Biology TgGPNΔSRD TgGPN missing the SRD at its N-terminus AtSPY Arabidopsis thaliana SPINDLY 03 medical and health sciences GST glutathione-S-transferase Animals Molecular Biology FG-Nup Phe/Gly-repeats nucleoporin Cell Nucleus posttranslational modification SRD serine-rich domain AAL Aleuria aurantia lectin 030102 biochemistry & molecular biology TgSPY Toxoplasma gondii SPINDLY nucleus fucosyltransferase DBA Dolichos biflorus agglutinin OGT O-GlcNAc transferase Cell Biology YFP yellow fluorescent protein 030104 developmental biology OFT O-fucosyltransferase chemistry NLS nuclear localization signal Cytoplasm Mutation biology.protein Apicomplexa Nuclear localization sequence |
| Zdroj: | The Journal of Biological Chemistry |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.ra120.015883 |
| Popis: | Once considered unusual, nucleocytoplasmic glycosylation is now recognized as a conserved feature of eukaryotes. While in animals, O-GlcNAc transferase (OGT) modifies thousands of intracellular proteins, the human pathogen Toxoplasma gondii transfers a different sugar, fucose, to proteins involved in transcription, mRNA processing, and signaling. Knockout experiments showed that TgSPY, an ortholog of plant SPINDLY and paralog of host OGT, is required for nuclear O-fucosylation. Here we verify that TgSPY is the nucleocytoplasmic O-fucosyltransferase (OFT) by 1) complementation with TgSPY-MYC3, 2) its functional dependence on amino acids critical for OGT activity, and 3) its ability to O-fucosylate itself and a model substrate and to specifically hydrolyze GDP-Fuc. While many of the endogenous proteins modified by O-Fuc are important for tachyzoite fitness, O-fucosylation by TgSPY is not essential. Growth of Δspy tachyzoites in fibroblasts is modestly affected, despite marked reductions in the levels of ectopically expressed proteins normally modified with O-fucose. Intact TgSPY-MYC3 localizes to the nucleus and cytoplasm, whereas catalytic mutants often displayed reduced abundance. Δspy tachyzoites of a luciferase-expressing type II strain exhibited infection kinetics in mice similar to wild-type but increased persistence in the chronic brain phase, potentially due to an imbalance of regulatory protein levels. The modest changes in parasite fitness in vitro and in mice, despite profound effects on reporter protein accumulation, and the characteristic punctate localization of O-fucosylated proteins suggest that TgSPY controls the levels of proteins to be held in reserve for response to novel stresses. |
| Databáze: | OpenAIRE |
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