Dataset Information

The Bimodal Sugar Code of Neutrophil Myeloperoxidase

ABSTRACT: Myeloperoxidase (MPO), an important diprotomeric glycoprotein in neutrophil-mediated immunity, produces microbicidal hypohalous acids, but the underpinning glycobiology remains elusive. Deep characterisation of neutrophil-derived MPO (nMPO) using advanced mass spectrometry demonstrated that under-processed oligomannosidic- and hyper-truncated paucimannosidic- and N-acetyl-β-D-glucosamine (GlcNAc) core-type asparagine-linked glycans decorate the protein. Occlusion of Asn355 and Asn391 and sterical hindrance of Asn323- and Asn483-glycans located in the MPO dimerisation zone were found to shape the local glycan processing thereby providing a molecular basis of the site-specific nMPO glycosylation. Native mass spectrometry, mass photometry, and glycopeptide profiling revealed extreme molecular complexity of diprotomeric nMPO arising from heterogeneous glycosylation, oxidation, chlorination and polypeptide truncation variants, and a lower-abundance monomer. Longitudinal profiling of maturing, mature, granule-separated, and pathogen-activated neutrophils demonstrated that MPO is dynamically expressed during granulopoiesis, unevenly distributed across granules and rapidly degranulated, but surprisingly carries uniform glycosylation across conditions. Complete proMPO-to-MPO maturation evidently occur during early/mid-stage granulopoiesis. The conserved Asn355- and Asn391-sequons displayed elevated GlcNAc signatures and higher oxidation and chlorination activity of the secretory vesicle/plasma membrane-resident MPO relative to MPO from other granules. Endoglycosidase H-treated nMPO displaying Asn355-/Asn391-GlcNAcylation recapitulated the activity gain and showed increased thermal stability and polypeptide accessibility relative to untreated nMPO as measured by activity assays, circular dichroism and molecular dynamics. Endoglycosidase H-treated nMPO also demonstrated elevated ceruloplasmin-mediated inhibition relative to nMPO. Modelling revealed that hyper-truncated Asn355-glycans positioned in the MPO:ceruloplasmin interface are critical for uninterrupted inhibition. We report on novel bimodal roles of the peculiar MPO glycosylation providing new insight into neutrophil glycobiology.

INSTRUMENT(S): Q Exactive HF

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Blood

SUBMITTER: Rebeca Kawahara

LAB HEAD: Morten Thaysen-Andersen

PROVIDER: PXD021131 | Pride | 2021-03-07

REPOSITORIES: Pride

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Publications

Hyper-truncated Asn355- and Asn391-glycans modulate the activity of neutrophil granule myeloperoxidase.

Tjondro Harry C HC Ugonotti Julian J Kawahara Rebeca R Chatterjee Sayantani S Loke Ian I Chen Siyun S Soltermann Fabian F Hinneburg Hannes H Parker Benjamin L BL Venkatakrishnan Vignesh V Dieckmann Regis R Grant Oliver C OC Bylund Johan J Rodger Alison A Woods Robert J RJ Karlsson-Bengtsson Anna A Struwe Weston B WB Thaysen-Andersen Morten M

The Journal of biological chemistry 20201210

Myeloperoxidase (MPO) plays essential roles in neutrophil-mediated immunity via the generation of reactive oxidation products. Complex carbohydrates decorate MPO at discrete sites, but their functional relevance remains elusive. To this end, we have characterised the structure-biosynthesis-activity relationship of neutrophil MPO (nMPO). Mass spectrometry demonstrated that nMPO carries both characteristic under-processed and hyper-truncated glycans. Occlusion of the Asn355/Asn391-glycosylation si ...[more]

PMID: 33273015

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Project description:Neutrophils are short-lived yet vital innate immune cells equipped with bioactive glycoproteins packed in cytosolic granules that can readily be mobilised to elicit an effective and timely response against invading pathogens. Since the dynamic glycosylation processes underpinning the dramatic metamorphosis associated with myeloid progenitor-to-neutrophil differentiation remain unmapped, we here perform a comprehensive spatiotemporal profiling of the complex N-glycoproteome of isolated granule populations from blood-derived neutrophils and during maturation of bone marrow-derived progenitors using glycomics-assisted glycoproteomics. Firstly, glycomics indicated that the granule populations of mature (resting) neutrophils exhibit distinctive glycophenotypes including, most strikingly, unusual paucimannosidic- and monoantennary complex-type N-glycans in azurophilic granules. The granule-specific N-glycosylation features were recapitulated by glycoproteomics, which also uncovered extensive site- and protein-specific N-glycosylation decorating 4,772 N-glycopeptides from 352 N-glycoproteins across the neutrophil granules. Excitingly, comprehensive mining of proteomics and transcriptomics data collected from discrete myeloid progenitor stages for glycopeptide and glyco-enzyme expression revealed that dramatic glycoproteome remodelling underpins the promyelocytic-to-metamyelocyte transition and that remodelling is driven predominantly by proteome expression changes rather than modulation of the glycosylation machinery. Notable exceptions were the oligosaccharyltransferase subunits responsible for initiation of N-glycoprotein biosynthesis that were strongly reduced with myeloid differentiation leading to reduced N-glycosylation efficiency in late-stage neutrophil maturation and in corresponding granules. Our study provides new spatiotemporal insights into the dynamic neutrophil N-glycoproteome, which exhibits intriguingly complex site-, protein- and granule-specific N-glycosylation features and which undergoes strong remodelling during myeloid progenitor-to-neutrophil metamorphosis.

Project description:Glycobiology plays a central role in prostate cancer (PCa), as evidenced by the aberrant glycosylation in PCa-derived glycoproteins. Understanding the protein glycosylation changes underling PCa onset and progression may open opportunities for the discovery of novel biomarkers for PCa detection and stratification as well as targets for PCa metastasis. Advances in mass spectrometry-based glycomics and glycoproteomics have opened up exciting avenues for deep characterisation of the immensely, yet poorly understood complex glycoproteome. In this study, we have used integrated glycomics and glycoproteomics to explore the protein, cell and tumour-grade specific N- and O- glycosylation signatures in surgically-removed fresh PCa tissues grouped into five PCa disease grades and tissues from benign prostatic hyperplasia patients (BPH). Porous graphitised carbon–liquid chromatography (PGC–LC)-MS/MS analysis was used to profile the N-and O-glycome, revealing PCa grade specific N and O glycosylation changes, including oligomannosidic and paucimannosidic, bisecting-GlcNAc and highly branched tri- and tetra-antennary fucosylated and sialylated N-glycans as well as sialylated core 1 and 2 type O-glycans. High resolution LC-MS/MS was then employed to capture the micro and macroheterogeneity of 1,085 N-glycosites (>7,400 unique N-glycopeptides) from 540 N-glycoproteins and 360 O-glycosites (>500 unique O-glycopeptides) from 178 O-glycoproteins and reveal protein and cell specific N- and O- glycosylation changes associated with PCa progression. We also showed PCa grade-specific increase in the expression of oligosaccharyltransferase (OST) subunits that correlate with changes in the site occupancy of N-glycoproteins. In conclusion, this study shows that integrated glycomics and glycoproteomics can provide unprecedented insight into key molecular features and site-specific glycan heterogeneity contributing to the highly diverse tumour-microenvironment and allow us to deconstruct the regulation of the protein, cell and tumour-grade-specific glycosylation associated with PCa onset and development.

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Dataset Information

The Bimodal Sugar Code of Neutrophil Myeloperoxidase

Publications

Hyper-truncated Asn355- and Asn391-glycans modulate the activity of neutrophil granule myeloperoxidase.

Similar Datasets

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