Format

Send to

Choose Destination
See comment in PubMed Commons below
J Phys Chem B. 2012 Jun 14;116(23):6923-35. doi: 10.1021/jp300197p. Epub 2012 Apr 2.

Quantitative nanoscale analysis of IgE-FcεRI clustering and coupling to early signaling proteins.

Author information

1
Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, USA.

Abstract

Antigen-mediated cross-linking of IgE bound to its receptor, FcεRI, initiates a transmembrane signaling cascade that results in mast cell activation in the allergic response. Using immunogold labeling of intact RBL mast cells and scanning electron microscopy (SEM), we visualize molecular reorganization of IgE-FcεRI and early signaling proteins on both leaflets of the plasma membrane, without the need for ripped off membrane sheets. As quantified by pair correlation analysis, we observe dramatic changes in the nanoscale distribution of IgE-FcεRI after binding of multivalent antigen to stimulate transmembrane signaling, and this is accompanied by similar clustering of Lyn and Syk tyrosine kinases, and adaptor protein LAT. We find that Lyn co-redistributes with IgE-FcεRI into clusters that cross-correlate throughout 20 min of stimulation. Inhibition of tyrosine kinase activity reduces the numbers of both IgE-FcεRI and Lyn in stimulated clusters. Coupling of these proteins is also decreased when membrane cholesterol is reduced either before or after antigen addition. These results provide evidence for involvement of FcεRI phosphorylation and cholesterol-dependent membrane structure in the interactions that accompany IgE-mediated activation of RBL mast cells. More generally, this SEM view of intact cell surfaces provides new insights into the nanoscale organization of receptor-mediated signaling complexes in the plasma membrane.

PMID:
22397623
PMCID:
PMC3376227
DOI:
10.1021/jp300197p
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for American Chemical Society Icon for PubMed Central
    Loading ...
    Support Center