The role of the conserved N-glycosylation site on each subunit of the Torpedo acetylcholine receptor (AChR) in the biogenesis and function of the receptor was examined by expressing site-directed mutant subunits in Xenopus oocytes. Different mutant subunits caused different effects. The most striking effect was seen with the mutant gamma subunit which, when co-expressed with alpha, beta, and delta subunits, caused degradation of all the subunits. N-Glycosylation of the other subunits appears to contribute to stability of the subunits and/or efficient insertion of the receptor into the plasma membrane, but is not required for assembly. The AChRs containing the mutant alpha subunit formed functional ion channels in the plasma membrane and their activity could be blocked by alpha-bungarotoxin (alpha-BuTX). Thus, attachment of a carbohydrate moiety at the conserved N-glycosylation site is not an absolute requirement for the formation of ACh and alpha-BuTX binding sites.
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http://dx.doi.org/10.1016/0169-328x(91)90016-q | DOI Listing |
Viruses
November 2024
Laboratory for Microbiology, Parasitology and Hygiene, Infla-Med Centre of Excellence, University of Antwerp (UA), Universiteitsplein 1 S.7, 2610 Antwerp, Belgium.
Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infections in young children, elderly and immunocompromised patients worldwide. The RSV fusion (F) protein, which has 5-6 N-glycosylation sites depending on the strain, is a major target for vaccine development. Two to three of these sites are located in the p27 peptide, which is considered absent in virions.
View Article and Find Full Text PDFOrg Biomol Chem
January 2025
School of Pharmaceutical Science and Technology, Hangzhou Institute of Advanced Study, Hangzhou 310024, China.
Glycosite-specific antibody-drug conjugates (gsADCs), which carry cytotoxic payloads at the conserved -glycosylation site, N297, of an IgG, have emerged as a promising ADC format with better therapeutic index. Conjugating the payloads aldehyde-based chemistry is more friendly to IgGs, and has been widely investigated. However, the efficiency of introducing an aldehyde tag at the N297 site is poor due to the complicated procedures required, such as the multiple-enzyme-catalyzed IgG glycoengineering process and the successive oxidation step, which always results in heterogeneous products and poor stability.
View Article and Find Full Text PDFFront Cell Infect Microbiol
December 2024
National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases (NITFID), National Health Commission Key Laboratory for Medical Virology and Viral Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.
Introduction: This study, conducted in China prior to RotaTeq's launch, examined the epidemiological, molecular, and evolutionary features of the G1P[8] genotype RVA in children admitted with diarrhea, to aid in evaluating its efficacy and impact on G1P[8] RVA in China.
Methods: Data from the Chinese viral diarrhea surveillance network were collected from January 2016 to December 2018. RVA strains identified as the G1P[8] genotype were subjected to whole-genome sequencing.
Congenital disorders of glycosylation (CDG) comprise a class of inborn errors of metabolism resulting from pathogenic variants in genes coding for enzymes involved in the asparagine-linked glycosylation of proteins. Unexpectedly to date, no CDG has been described for , encoding the alpha-1,2-glucosyltransferase catalyzing the final step of lipid-linked oligosaccharide biosynthesis. Genome-wide association studies (GWAS) of human traits in the UK Biobank revealed significant SNP associations with short sleep duration, reduced napping frequency, later sleep timing and evening diurnal preference as well as cardiac traits at a genomic locus containing a pair of paralogous enzymes and .
View Article and Find Full Text PDFMol Cell Proteomics
December 2024
Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands; Netherlands Proteomic Center, Utrecht, The Netherlands. Electronic address:
Sperm cells are terminally differentiated cells that are essential for reproduction in sexually reproducing species. Consistent with their highly specialized function, sperm cells harbor a unique proteome containing many proteins not expressed in somatic cells. In contrast, the post-translational landscape of the sperm proteome remains largely unexplored, limiting our understanding of how modifications such as glycosylation impact sperm function and sperm-egg interactions.
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