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Biology Letters Jun 2024Glycation reactions play a key role in the senescence process and are involved in numerous age-related pathologies, such as diabetes complications or Alzheimer's... (Review)
Review
Glycation reactions play a key role in the senescence process and are involved in numerous age-related pathologies, such as diabetes complications or Alzheimer's disease. As a result, past studies on glycation have mostly focused on human and laboratory animal models for medical purposes. Very little is known about glycation and its link to senescence in wild animal species. Yet, despite feeding on high-sugar diets, several bat and bird species are long-lived and seem to escape the toxic effects of high glycaemia. The study of these models could open new avenues both for understanding the mechanisms that coevolved with glycation resistance and for treating the damaging effects of glycations in humans. Our understanding of glycaemia's correlation to proxies of animals' pace of life is emerging in few wild species; however, virtually nothing is known about their resistance to glycation, nor on the relationship between glycation, species' life-history traits and individual fitness. Our review summarizes the scarce current knowledge on the links between glycation and life-history traits in non-conventional animal models, highlighting the predominance of avian research. We also investigate some key molecular and physiological parameters involved in glycation regulation, which hold promise for future research on fitness and senescence of individuals.
Topics: Animals; Life History Traits; Birds; Models, Animal; Glycosylation; Aging; Glycation End Products, Advanced
PubMed: 38863347
DOI: 10.1098/rsbl.2023.0601 -
Microbiology Resource Announcements Jun 2024, a member of the family and species , is an F1 cluster phage that infects mc²155. The Maravista genome has 61.3% GC content, is 60,140 bp in length, and encodes 104...
, a member of the family and species , is an F1 cluster phage that infects mc²155. The Maravista genome has 61.3% GC content, is 60,140 bp in length, and encodes 104 putative genes. Maravista encodes two putative glycosyltransferases, suggesting glycosylation of its capsid protein.
PubMed: 38860805
DOI: 10.1128/mra.00502-24 -
American Journal of Cancer Research 2024Chemotherapy is the principal treatment for advanced cancer patients. However, chemotherapeutic resistance, an important hallmark of cancer, is considered as a key... (Review)
Review
Chemotherapy is the principal treatment for advanced cancer patients. However, chemotherapeutic resistance, an important hallmark of cancer, is considered as a key impediment to effective therapy in cancer patients. Multiple signaling pathways and factors have been underscored to participate in governing drug resistance. Posttranslational modifications, including ubiquitination, glycosylation, acetylation and phosphorylation, have emerged as key players in modulating drug resistance in gynecological tumors, such as ovarian cancer, cervical cancer and endometrial cancer. In this review article, we summarize the role of ubiquitination in governing drug sensitivity in gynecological cancers. Moreover, we describe the numerous compounds that target ubiquitination in gynecological cancers to reverse chemotherapeutic resistance. In addition, we provide the future perspectives to fully elucidate the mechanisms by which ubiquitination controls drug resistance in gynecological tumors, contributing to restoring drug sensitivity. This review highlights the complex interplay between ubiquitination and drug resistance in gynecological tumors, providing novel insights into potential therapeutic targets and personalized treatment strategies to overcome the bottleneck of drug resistance.
PubMed: 38859858
DOI: 10.62347/WYKZ9784 -
American Journal of Cancer Research 2024Whether serum Mac-2 binding protein glycosylation isomer (M2BPGi) level at year 5 of treatment could predict hepatocellular carcinoma (HCC) development and mortality...
Mac-2 binding protein glycosylation isomer at 5 years of antiviral therapy predict hepatocellular carcinoma and mortality beyond year 5 in chronic hepatitis B patients with cirrhosis.
Whether serum Mac-2 binding protein glycosylation isomer (M2BPGi) level at year 5 of treatment could predict hepatocellular carcinoma (HCC) development and mortality beyond year 5 of entecavir or tenofovir disoproxil fumarate (TDF) treatment in chronic hepatitis B (CHB) patients with cirrhosis remain unclear. This retrospective study investigated the role of M2BPGi level at year 5 of treatment in predicting HCC and mortality beyond year 5 in CHB patients with cirrhosis. This study analyzed 1385 cirrhotic patients receiving entecavir or TDF treatment. Of them, 899 patients who did not develop HCC within the first 5 years of treatment were enrolled. In the entire cohort, there was no significant difference in the annual incidence of HCC before and after year 5 of entecavir or TDF treatment ( = 0.455). Multivariable Cox analysis identified old age, higher AFP and M2BPGi levels at 5 years of treatment as independent predictors of HCC occurrence beyond year 5. We developed the HCC risk prediction model, AMA, based on age, M2BPGi and AFP levels at 5 years of treatment, with the total score ranging from 0 to 8. The AMA model accurately categorized patients into low (≤2), medium (2-5), and high (≥5) risk groups in the development and validation groups (<0.001) and exhibited good discriminant function in predicting HCC beyond year 5 in cirrhotic patients (AUROC: 0.743 at 5 years). The M2BPGi of 1.0 COI at 5 years of treatment stratified the risk of all-cause and liver-related mortality beyond year 5 (<0.001). In conclusions, M2BPGi level at 5 years of treatment is a useful marker for predicting HCC development and mortality beyond year 5 of entecavir or TDF therapy in CHB patients with cirrhosis.
PubMed: 38859836
DOI: 10.62347/DAGB7277 -
Microbial Biotechnology Jun 2024The application of bacterial oligosaccharyltransferases (OSTs) such as the Campylobacter jejuni PglB for glycoengineering has attracted considerable interest in...
The application of bacterial oligosaccharyltransferases (OSTs) such as the Campylobacter jejuni PglB for glycoengineering has attracted considerable interest in glycoengineering and glycoconjugate vaccine development. However, PglB has limited specificity for glycans that can be transferred to candidate proteins, which along with other factors is dependent on the reducing end sugar of glycans. In this study, we developed a cell-free glycosylation assay that offers the speed and simplicity of a 'yes' or 'no' determination. Using the assay, we tested the activity of eleven PglBs from Campylobacter species and more distantly related bacteria. The following assorted glycans with diverse reducing end sugars were tested for transfer, including Streptococcus pneumoniae capsule serotype 4, Salmonella enterica serovar Typhimurium O antigen (B1), Francisella tularensis O antigen, Escherichia coli O9 antigen and Campylobacter jejuni heptasaccharide. Interestingly, while PglBs from the same genus showed high activity, whereas divergent PglBs differed in their transfer of glycans to an acceptor protein. Notably for glycoengineering purposes, Campylobacter hepaticus and Campylobacter subantarcticus PglBs showed high glycosylation efficiency, with C. hepaticus PglB potentially being useful for glycoconjugate vaccine production. This study demonstrates the versatility of the cell-free assay in rapidly assessing an OST to couple glycan/carrier protein combinations and lays the foundation for future screening of PglBs by linking amino acid similarity to glycosyltransferase activity.
Topics: Hexosyltransferases; Glycosylation; Membrane Proteins; Campylobacter; Polysaccharides; Cell-Free System; Campylobacter jejuni; Bacterial Proteins; Glycoconjugates
PubMed: 38858807
DOI: 10.1111/1751-7915.14480 -
Iranian Journal of Microbiology Apr 2024The influenza A(H1N1) virus is known for large outbreaks, epidemics and pandemics worldwide owing to its genome plasticity which evolves constantly. In the year 2015 and...
BACKGROUND AND OBJECTIVES
The influenza A(H1N1) virus is known for large outbreaks, epidemics and pandemics worldwide owing to its genome plasticity which evolves constantly. In the year 2015 and then in 2017, India witnessed an upsurge in cases.
MATERIALS AND METHODS
The study was carried out in this period (2015-2017) with samples from 5 states across north India. The hemagglutinin 1 (HA1) and non-structural 1 (NS1) gene segments of the viral genome were characterised by phylogenetic analysis, selection pressure analysis, prediction of potential glycosylation sites and phylodynamic analysis of the study strains.
RESULTS
The study strains belonged to genogroup 6B. A total of 12 mutations were observed, half of which were located on the key receptor binding region of the HA1 protein. Established virulence markers D222G, S183P were observed in 2017 samples. Acquisition of an extra glycosylation site was observed in few strains from 2017 and 2016. Selection pressure analysis found the average dN/dS (v) ratio of 0.2106 and few codon sites in particular showed significant evidence of being under negative selection.
CONCLUSION
The genogroup 6B continues to be the dominant circulating strain in Indian subcontinent region however the presence of pathogenic mutations in the 2017 strains from north India underlines the importance of continued molecular surveillance.
PubMed: 38854978
DOI: 10.18502/ijm.v16i2.15358 -
Molecular & Cellular Proteomics : MCP Jun 2024Protein O-linked mannose (O-Man) glycosylation is an evolutionary conserved post-translational modification (PTM) that fulfills important biological roles during...
Protein O-linked mannose (O-Man) glycosylation is an evolutionary conserved post-translational modification (PTM) that fulfills important biological roles during embryonic development. Three non-redundant enzyme families, POMT1/POMT2, TMTC1-4 and TMEM260, selectively coordinate the initiation of protein O-Man glycosylation on distinct classes of transmembrane proteins, including α-dystroglycan, cadherins and plexin receptors. However, a systematic investigation of their substrate specificities is lacking, in part due to the ubiquitous expression of O-Man glycosyltransferases in cells, which precludes analysis of pathway-specific O-Man glycosylation on a proteome-wide scale. Here, we apply a targeted workflow for membrane glycoproteomics across five human cell lines to extensively map O-Man substrates and genetically deconstruct O-Man initiation by individual and combinatorial knock-out (KO) of O-Man glycosyltransferase genes. We established a human cell library for analysis of substrate specificities of individual O-Man initiation pathways by quantitative glycoproteomics. Our results identify 180 O-Man glycoproteins, demonstrate new protein targets for the POMT1/POMT2 pathway and show that TMTC1-4 and TMEM260 pathways widely target distinct Ig-like protein domains of plasma membrane proteins involved in cell-cell and cell-extracellular matrix interactions. The identification of O-Man on Ig-like folds adds further knowledge on the emerging concept of domain-specific O-Man glycosylation which opens for functional studies of O-Man glycosylated adhesion molecules and receptors.
PubMed: 38851451
DOI: 10.1016/j.mcpro.2024.100796 -
Journal of Biomedical Science Jun 2024Flavivirus is a challenge all over the world. The replication of flavivirus takes place within membranous replication compartments (RCs) derived from endoplasmic...
BACKGROUND
Flavivirus is a challenge all over the world. The replication of flavivirus takes place within membranous replication compartments (RCs) derived from endoplasmic reticulum (ER). Flavivirus NS1 proteins have been proven essential for the formation of viral RCs by remodeling the ER. The glycosylation of flavivirus NS1 proteins is important for viral replication, yet the underlying mechanism remains unclear.
METHODS
HeLa cells were used to visualize the ER remodeling effects induced by NS1 expression. ZIKV replicon luciferase assay was performed with BHK-21 cells. rZIKV was generated from BHK-21 cells and the plaque assay was done with Vero Cells. Liposome co-floating assay was performed with purified NS1 proteins from 293T cells.
RESULTS
We found that the glycosylation of flavivirus NS1 contributes to its ER remodeling activity. Glycosylation deficiency of NS1, either through N-glycosylation sites mutations or tunicamycin treatment, compromises its ER remodeling activity and interferes with viral RCs formation. Disruption of NS1 glycosylation results in abnormal aggregation of NS1, rather than reducing its membrane-binding activity. Consequently, deficiency in NS1 glycosylation impairs virus replication.
CONCLUSIONS
In summary, our results highlight the significance of NS1 glycosylation in flavivirus replication and elucidate the underlying mechanism. This provides a new strategy for combating flavivirus infections.
Topics: Viral Nonstructural Proteins; Glycosylation; Virus Replication; Humans; Animals; Viral Replication Compartments; HeLa Cells; Chlorocebus aethiops; Flavivirus; Endoplasmic Reticulum; Vero Cells
PubMed: 38849802
DOI: 10.1186/s12929-024-01048-z -
Clinical Proteomics Jun 2024Allergen immunotherapy (AIT) is the only disease-modifying therapy that can achieve immune tolerance in patients through long-term allergen stimulation. Glycans play...
BACKGROUND
Allergen immunotherapy (AIT) is the only disease-modifying therapy that can achieve immune tolerance in patients through long-term allergen stimulation. Glycans play crucial roles in allergic disease, but no information on changes in glycosylation related to an allergic tolerance status has been reported.
METHODS
Fifty-seven patients with house dust mite (HDM) allergies were enrolled. Twenty-eight patients were not treated with AIT, 19 patients had just entered the AIT maintenance treatment phase, and 10 patients had been in the AIT maintenance phase for more than 1 year. Serum protein N-glycans were analyzed by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), which included linkage-specific sialylation information.
RESULTS
Eighty-four N-glycans were identified in all three groups. Compared with the patients treated without AIT, the patients treated with AIT for a shorter time showed downregulated expression of high-mannose glycans and upregulated expression of α2,6 sialic acid. The patients treated with AIT in the maintenance phase for over 1 year, which was considered the start of immunological tolerance, showed downregulated expression of biantennary N-glycans and upregulated expression of multibranched and complex N-glycans. Nine N-glycans were changed between allergic and allergic-tolerant patients.
CONCLUSIONS
The glycan form changed from mannose to a more complex type as treatment time increased, and multibranched complex glycans have the potential to be used as a monitoring indicator of immune tolerance. This serum N-glycome analysis provided important information for a deeper understanding of AIT treatment at the molecular level.
PubMed: 38849742
DOI: 10.1186/s12014-024-09491-8 -
The Journal of Investigative Dermatology Jun 2024
PubMed: 38848987
DOI: 10.1016/j.jid.2024.03.044