CD22, a negative regulator of B cell antigen receptor signaling, binds glycoconjugates terminating in alpha2, 6 sialic acid. The physiological ligand(s) for CD22 remain unknown. We asked whether the sialic acid binding domains are necessary for CD22 to function as a negative regulator. We generated two mutants that lack sialic acid binding activity and expressed them in a novel CD22(-/-) murine B cell line. Anti-IgM activated B cells expressing either CD22 mutant had greater Ca(2+) responses than cells expressing wild-type CD22. Each variant also had reduced CD22 tyrosine phosphorylation and Src homology 2 domain-containing protein tyrosine phosphatase-1 association. These data suggest that the alpha2, 6 sialic acid ligand binding activity of CD22 is critical for its negative regulatory functions.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2193702 | PMC |
| http://dx.doi.org/10.1084/jem.20011796 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
GGCX promotes Eurasian avian-like H1N1 swine influenza virus adaption to interspecies receptor binding.
Nat Commun
January 2025
National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China.
The Eurasian avian-like (EA) H1N1 swine influenza virus (SIV) possesses the capacity to instigate the next influenza pandemic, owing to its heightened affinity for the human-type α-2,6 sialic acid (SA) receptor. Nevertheless, the molecular mechanisms underlying the switch in receptor binding preferences of EA H1N1 SIV remain elusive. In this study, we conduct a comprehensive genome-wide CRISPR/Cas9 knockout screen utilizing EA H1N1 SIV in porcine kidney cells.
View Article and Find Full Text PDFQuantitative Glycan-Protein Cross-Linking Mass Spectrometry Using Enrichable Linkers Reveals Extensive Glycan-Mediated Protein Interaction Networks.
Anal Chem
January 2025
Department of Chemistry, University of California, Davis, California 95616, United States.
Protein-protein interactions in the cell membrane are typically mediated by glycans, with terminal sialic acid often involved in these interactions. To probe the nature of the interactions, we developed quantitative cross-linking methods involving the glycans of the glycoproteins and the polypeptide moieties of proteins. We designed and synthesized biotinylated enrichable cross-linkers that were click-tagged to metabolically incorporate azido-sialic acid on cell surface glycans to allow cross-linking of the azido-glycans with lysine residues on proximal polypeptides.
View Article and Find Full Text PDFComprehensive molecular epidemiology of influenza viruses in Brazil: insights from a nationwide analysis.
Virus Evol
November 2024
Center for Viral Surveillance and Serological Assessment (CeVIVAS), Instituto Butantan, Avenida Vital Brasil, 1500, Butantã, São Paulo, São Paulo 05503-900, Brazil.
Influenza A and B viruses represent significant global health threats, contributing substantially to morbidity and mortality rates. However, a comprehensive understanding of the molecular epidemiology of these viruses in Brazil, a continental-size country and a crucial hub for the entry, circulation, and dissemination of influenza viruses within South America, still needs to be improved. This study addresses this gap by consolidating data and samples across all Brazilian macroregions, as part of the Center for Viral Surveillance and Serological Assessment project, together with an extensive number of other Brazilian sequences provided by a public database during the epidemic seasons spanning 2021-23.
View Article and Find Full Text PDFSialic Acid-Modified nanomedicines modulate neutrophils for dual therapy of cancer and sepsis: Addressing neglected sepsis comorbidities during cancer treatment.
Int J Pharm
January 2025
College of Pharmacy, Shenyang Pharmaceutical University, Shenyang, Liaoning 110016, China. Electronic address:
Advanced cancer patients face a high risk of sepsis due to immune suppression and infection susceptibility. To tackle this challenge, we developed an innovative animal model that simulates the clinical scenario of late-stage cancer complicated by sepsis and designed a sialic acid (SA)-modified paclitaxel (PTX) liposome (PTX-SAL). This formulation specifically targets overactivated peripheral blood neutrophils (PBNs) by binding to L-selectin on their surface.
View Article and Find Full Text PDFSLC35A2 modulates paramyxovirus fusion events during infection.
PLoS Pathog
January 2025
Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, United States of America.
Paramyxoviruses are significant human and animal pathogens that include mumps virus (MuV), Newcastle disease virus (NDV) and the murine parainfluenza virus Sendai (SeV). Despite their importance, few host factors implicated in paramyxovirus infection are known. Using a recombinant SeV expressing destabilized eGFP (rSeVCdseGFP) in a loss-of-function CRISPR screen, we identified the CMP-sialic acid transporter (CST) gene SLC35A1 and the UDP-galactose transporter (UGT) gene SLC35A2 as essential for paramyxovirus infection.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!