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International Journal of Molecular... Sep 2023Breast cancer represents a paramount global health challenge, warranting intensified exploration of the molecular underpinnings influencing its progression to facilitate... (Review)
Review
Breast cancer represents a paramount global health challenge, warranting intensified exploration of the molecular underpinnings influencing its progression to facilitate the development of precise diagnostic instruments and customized therapeutic regimens. Historically, the Golgi apparatus has been acknowledged for its primary role in protein sorting and trafficking within cellular contexts. However, recent findings suggest a potential link between modifications in Golgi apparatus function and organization and the pathogenesis of breast cancer. This review delivers an exhaustive analysis of this correlation. Specifically, we examine the consequences of disrupted protein glycosylation, compromised protein transport, and inappropriate oncoprotein processing on breast cancer cell dynamics. Furthermore, we delve into the impacts of Golgi-mediated secretory routes on the release of pro-tumorigenic factors during the course of breast cancer evolution. Elucidating the nuanced interplay between the Golgi apparatus and breast cancer can pave the way for innovative therapeutic interventions and the discovery of biomarkers, potentially enhancing the diagnostic, prognostic, and therapeutic paradigms for afflicted patients. The advancement of such research could substantially expedite the realization of these objectives.
Topics: Humans; Female; Breast Neoplasms; Breast; Golgi Apparatus; Carcinogenesis; Biological Transport
PubMed: 37762375
DOI: 10.3390/ijms241814073 -
The FEBS Journal Aug 2023Glycosylation is the most prevalent protein post-translational modification, with a quarter of glycosylated proteins having enzymatic properties. Yet, the full impact of...
Glycosylation is the most prevalent protein post-translational modification, with a quarter of glycosylated proteins having enzymatic properties. Yet, the full impact of glycosylation on the protein structure-function relationship, especially in enzymes, is still limited. Here, we show that glycosylation rigidifies the important commercial enzyme horseradish peroxidase (HRP), which in turn increases its turnover and stability. Circular dichroism spectroscopy revealed that glycosylation increased holo-HRP's thermal stability and promoted significant helical structure in the absence of haem (apo-HRP). Glycosylation also resulted in a 10-fold increase in enzymatic turnover towards o-phenylenediamine dihydrochloride when compared to its nonglycosylated form. Utilising a naturally occurring site-specific probe of active site flexibility (Trp117) in combination with red-edge excitation shift fluorescence spectroscopy, we found that glycosylation significantly rigidified the enzyme. In silico simulations confirmed that glycosylation largely decreased protein backbone flexibility, especially in regions close to the active site and the substrate access channel. Thus, our data show that glycosylation does not just have a passive effect on HRP stability but can exert long-range effects that mediate the 'native' enzyme's activity and stability through changes in inherent dynamics.
Topics: Enzyme Stability; Glycosylation; Catalytic Domain; Protein Processing, Post-Translational; Spectrometry, Fluorescence
PubMed: 37004154
DOI: 10.1111/febs.16783 -
MBio Feb 2024The glycosylation of viral envelope proteins can play important roles in virus biology and immune evasion. The spike (S) glycoprotein of severe acute respiratory...
The glycosylation of viral envelope proteins can play important roles in virus biology and immune evasion. The spike (S) glycoprotein of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) includes 22 N-linked glycosylation sequons and 17 O-linked glycosites. We investigated the effect of individual glycosylation sites on SARS-CoV-2 S function in pseudotyped virus infection assays and on sensitivity to monoclonal and polyclonal neutralizing antibodies. In most cases, the removal of individual glycosylation sites decreased the infectiousness of the pseudotyped virus. For glycosylation mutants in the N-terminal domain and the receptor-binding domain (RBD), reduction in pseudotype infectivity was predicted by a commensurate reduction in the level of virion-incorporated S protein and reduced S trafficking to the cell surface. Notably, the presence of a glycan at position N343 within the RBD had diverse effects on neutralization by RBD-specific monoclonal antibodies cloned from convalescent individuals. The N343 glycan reduced the overall sensitivity to polyclonal antibodies in plasma from COVID-19 convalescent individuals, suggesting a role for SARS-CoV-2 S glycosylation in immune evasion. However, vaccination of convalescent individuals produced neutralizing activity that was resilient to the inhibitory effect of the N343 glycan.IMPORTANCEThe attachment of glycans to the spike proteins of viruses during their synthesis and movement through the secretory pathway can affect their properties. This study shows that the glycans attached to the severe acute respiratory syndrome coronavirus-2 spike protein enable its movement to the cell surface and incorporation into virus particles. Certain glycans, including one that is attached to asparagine 343 in the receptor-binding domain of the spike protein, can also affect virus neutralization by antibodies. This glycan can increase or decrease sensitivity to individual antibodies, likely through direct effects on antibody epitopes and modulation of spike conformation. However, the overall effect of the glycan in the context of the polyclonal mixture of antibodies in convalescent serum is to reduce neutralization sensitivity. Overall, this study highlights the complex effects of glycosylation on spike protein function and immune evasion.
Topics: Humans; SARS-CoV-2; COVID-19; Spike Glycoprotein, Coronavirus; Antibodies, Viral; Glycosylation; COVID-19 Serotherapy; Antibodies, Neutralizing; Polysaccharides; Neutralization Tests
PubMed: 38193662
DOI: 10.1128/mbio.01672-23 -
Frontiers in Plant Science 2024N-Acetylglucosamine (GlcNAc), a fundamental amino sugar moiety, is essential for protein glycosylation, glycolipid, GPI-anchor protein, and cell wall components. Uridine... (Review)
Review
N-Acetylglucosamine (GlcNAc), a fundamental amino sugar moiety, is essential for protein glycosylation, glycolipid, GPI-anchor protein, and cell wall components. Uridine diphosphate-GlcNAc (UDP-GlcNAc), an active form of GlcNAc, is synthesized through the hexosamine biosynthesis pathway (HBP). Although HBP is highly conserved across organisms, the enzymes involved perform subtly distinct functions among microbes, mammals, and plants. A complete block of HBP normally causes lethality in any life form, reflecting the pivotal role of HBP in the normal growth and development of organisms. Although HBP is mainly composed of four biochemical reactions, HBP is exquisitely regulated to maintain the homeostasis of UDP-GlcNAc content. As HBP utilizes substrates including fructose-6-P, glutamine, acetyl-CoA, and UTP, endogenous nutrient/energy metabolites may be integrated to better suit internal growth and development, and external environmental stimuli. Although the genes encoding HBP enzymes are well characterized in microbes and mammals, they were less understood in higher plants in the past. As the HBP-related genes/enzymes have largely been characterized in higher plants in recent years, in this review we update the latest advances in the functions of the HBP-related genes in higher plants. In addition, HBP's salvage pathway and GlcNAc-mediated two major co- or post-translational modifications, N-glycosylation and O-GlcNAcylation, are also included in this review. Further knowledge on the function of HBP and its product conjugates, and the mechanisms underlying their response to deleterious environments might provide an alternative strategy for agricultural biofortification in the future.
PubMed: 38510444
DOI: 10.3389/fpls.2024.1349064 -
Glycobiology Dec 2023Glycosylation plays a crucial role in many aspects of cell biology, including cellular and organismal integrity, structure-and-function of many glycosylated molecules in... (Review)
Review
Glycosylation plays a crucial role in many aspects of cell biology, including cellular and organismal integrity, structure-and-function of many glycosylated molecules in the cell, signal transduction, development, cancer, and in a number of diseases. Besides, at the inter-organismal level of interaction, a variety of glycosylated molecules are involved in the host-microbiota recognition and initiation of downstream signalling cascades depending on the outcomes of the glycome-mediated ascertainment. The role of glycosylation in host-microbe interactions is better elaborated within the context of virulence and pathogenicity in bacterial infection processes but the symbiotic host-microbe relationships also involve substantive glycome-mediated interactions. The works in the latter field have been reviewed to a much lesser extent, and the main aim of this mini-review is to compensate for this deficiency and summarise the role of glycomics in host-microbe symbiotic interactions.
Topics: Host Microbial Interactions; Symbiosis; Microbiota; Glycosylation; Glycomics
PubMed: 37741057
DOI: 10.1093/glycob/cwad073 -
Journal of Virology Oct 2023Gaining insight into the cell-entry mechanisms of swine acute diarrhea syndrome coronavirus (SADS-CoV) is critical for investigating potential cross-species infections....
Gaining insight into the cell-entry mechanisms of swine acute diarrhea syndrome coronavirus (SADS-CoV) is critical for investigating potential cross-species infections. Here, we demonstrated that pretreatment of host cells with tunicamycin decreased SADS-CoV attachment efficiency, indicating that N-linked glycosylation of host cells was involved in SADS-CoV entry. Common N-linked sugars Neu5Gc and Neu5Ac did not interact with the SADS-CoV S1 protein, suggesting that these molecules were not involved in SADS-CoV entry. Additionally, various host proteases participated in SADS-CoV entry into diverse cells with different efficiencies. Our findings suggested that SADS-CoV may exploit multiple pathways to enter cells, providing insights into intervention strategies targeting the cell entry of this virus.
Topics: Animals; Alphacoronavirus; Coronavirus Infections; Endopeptidases; Glycoproteins; Swine; Swine Diseases; Virus Internalization; Tunicamycin; Glycosylation
PubMed: 37772826
DOI: 10.1128/jvi.00916-23 -
BioRxiv : the Preprint Server For... Nov 2023Brain somatic variants in are associated with clinically drug-resistant epilepsy and developmental brain malformations, including mild malformation of cortical...
Brain somatic variants in are associated with clinically drug-resistant epilepsy and developmental brain malformations, including mild malformation of cortical development with oligodendroglial hyperplasia in epilepsy (MOGHE). encodes a uridine diphosphate galactose translocator that is essential for protein glycosylation; however, the neurodevelopmental mechanisms by which disruption leads to clinical and histopathological features remain unspecified. We hypothesized that focal knockout (KO) or knockdown (KD) of in the developing mouse cortex would disrupt cerebral cortical development through altered neuronal migration and cause changes in network excitability. We used electroporation (IUE) to introduce CRISPR/Cas9 and targeted guide RNAs or short-hairpin RNAs to achieve KO or KD, respectively, during early corticogenesis. Following KO or KD, we observed disrupted radial migration of transfected neurons evidenced by heterotopic cells located in lower cortical layers and in the sub-cortical white matter. KO in neurons did not induce changes in oligodendrocyte number, suggesting that the oligodendroglial hyperplasia observed in MOGHE originates from distinct cell autonomous effects. Spontaneous seizures were not observed, but intracranial EEG recordings after focal KO showed a reduced seizure threshold following pentylenetetrazol injection. These results demonstrate that KO or KD disrupts corticogenesis through altered neuronal migration.
PubMed: 38077069
DOI: 10.1101/2023.11.29.569243 -
Frontiers in Immunology 2023B7-H6 is a novel immune checkpoint molecule that triggers NK cell cytotoxicity, but the role of N-glycosylation in B7-H6 is poorly understood. We here identified the...
B7-H6 is a novel immune checkpoint molecule that triggers NK cell cytotoxicity, but the role of N-glycosylation in B7-H6 is poorly understood. We here identified the existence of N-glycosylation of B7-H6 in different cell lines and exogenous expression cells by PNGase F digestion and tunicamycin blockage. Subsequently, we demonstrated that B7-H6 contains 6 functional N-linked glycosylation sites by single site mutation and electrophoresis. Phylogenetical and structural analysis revealed that N43 and N208 glycan are conserved in jawed vertebrates and may thus contribute more to the biological functions. We further demonstrated that N43 and N208 glycosylation are essential for B7-H6 to trigger NK cell activation. Mechanistically, we found that N43 and N208 glycan contributed to the stability and membrane expression of B7-H6 protein. Lack of N208 glycosylation led to membrane B7-H6 shedding, while N43 mutation resulted in impaired B7-H6/NKp30 binding affinity. Together, our findings highlight the significance of N-linked glycosylation in B7-H6 biological functions and suggest potential targets for modulating NK cell-mediated immunity.
Topics: Animals; Killer Cells, Natural; Glycosylation; Lymphocyte Activation; Immunity, Cellular; Polysaccharides
PubMed: 38035117
DOI: 10.3389/fimmu.2023.1255667 -
Cells Feb 2024Glycoproteomics has accelerated in recent decades owing to numerous innovations in the analytical workflow. In particular, new mass spectrometry strategies have... (Review)
Review
Glycoproteomics has accelerated in recent decades owing to numerous innovations in the analytical workflow. In particular, new mass spectrometry strategies have contributed to inroads in -glycoproteomics, a field that lags behind -glycoproteomics due to several unique challenges associated with the complexity of -glycosylation. This review will focus on progress in sample preparation, enrichment strategies, and MS/MS techniques for the identification and characterization of -glycoproteins.
Topics: Tandem Mass Spectrometry; Proteomics; Glycosylation; Glycoproteins; Specimen Handling
PubMed: 38474358
DOI: 10.3390/cells13050394 -
International Journal of Nanomedicine 2023The purpose of this study was to improve the immune compatibility and targeting abilities of IL10 nanoparticles coated with platelet membrane (IL10-PNPs) by...
PURPOSE
The purpose of this study was to improve the immune compatibility and targeting abilities of IL10 nanoparticles coated with platelet membrane (IL10-PNPs) by glycosylation engineering in order to effectively reduce restenosis after vascular injury.
MATERIALS AND METHODS
In this study, we removed sialic acids and added α (1,2)-fucose and α (1,3)-fucose to platelet membrane glycoprotein, thus engineering the glycosylation of IL10-PNPs (IL10-GE-PNPs). In vitro and in vivo experiments were conducted to evaluate the targeting and regulatory effects of IL10-GE-PNPs on macrophage polarization, as well as the influence of IL10-GE-PNPs on the phenotypic transformation, proliferation, and migration of smooth muscle cells, and its potential in promoting the repair function of endothelial cells within an inflammatory environment. In order to assess the distribution of IL10-GE-PNP in different organs, in vivo imaging experiments were conducted.
RESULTS
IL10-GE-PNPs were successfully constructed and demonstrated to effectively target and regulate macrophage polarization in both in vitro and in vivo settings. This regulation resulted in reduced proliferation and migration of smooth muscle cells and promoted the repair of endothelial cells in an inflammatory environment. Consequently, restenosis after vascular injury was reduced. Furthermore, the deposition of IL10-GE-PNPs in the liver and spleen was significantly reduced compared to IL10-PNPs.
CONCLUSION
IL10-GE-PNPs emerged as a promising candidate for targeting vascular injury and exhibited potential as an innovative drug delivery system for suppressing vascular restenosis. The engineered glycosylation of IL10-PNPs improved their immune compatibility and targeting abilities, making them an excellent therapeutic option.
Topics: Humans; Endothelial Cells; Fucose; Glycosylation; Interleukin-10; Nanoparticles; Vascular System Injuries
PubMed: 37693888
DOI: 10.2147/IJN.S423186