Tyrosine phosphorylation of the high affinity immunoglobulin (Ig)E receptor (FcεRI) by the Src family kinase Lyn is the first known biochemical step that occurs during activation of mast cells and basophils after cross-linking of FcεRI by antigen. The hypothesis that specialized regions in the plasma membrane, enriched in sphingolipids and cholesterol, facilitate the coupling of Lyn and FcεRI was tested by investigating functional and structural effects of cholesterol depletion on Lyn/FcεRI interactions. We find that cholesterol depletion with methyl-β-cyclodextrin substantially reduces stimulated tyrosine phosphorylation of FcεRI and other proteins while enhancing more downstream events that lead to stimulated exocytosis. In parallel to its inhibition of tyrosine phosphorylation, cholesterol depletion disrupts the interactions of aggregated FcεRI and Lyn on intact cells and also disrupts those interactions with detergent-resistant membranes that are isolated by sucrose gradient ultracentrifugation of lysed cells. Importantly, cholesterol repletion restores receptor phosphorylation together with the structural interactions. These results provide strong evidence that membrane structure, maintained by cholesterol, plays a critical role in the initiation of FcεRI signaling.
Critical Role for Cholesterol in Lyn-mediated Tyrosine Phosphorylation of FcεRI and Their Association with Detergent-resistant Membranes
Published 1999 in Journal of Cell Biology
ABSTRACT
PUBLICATION RECORD
- Publication year
1999
- Venue
Journal of Cell Biology
- Publication date
1999-05-17
- Fields of study
Biology, Medicine, Chemistry
- Identifiers
- External record
- Source metadata
Semantic Scholar, PubMed
CITATION MAP
EXTRACTION MAP
CLAIMS
- No claims are published for this paper.
CONCEPTS
- No concepts are published for this paper.
REFERENCES
Showing 1-58 of 58 references · Page 1 of 1