Purified rat serosal mast cells were sensitized with mouse immunoglobulin E (IgE) anti-2,4-dinitrophenyl antibody, partially depleted of phosphate, labeled with [32P]orthophosphate, and stimulated with dinitrophenylated bovine serum albumin or control protein. After 15-120 seconds at 37°C, the cells were extracted with nonionic detergent. IgE receptors were purified by repetitive affinity chromatography and were analyzed by NaDodSO4/polyacrylamide gel electrophoresis and radioautography. Antigenic stimulation of intact rat mast cells produced a rapid and marked increase in the phosphorylation of the surface-exposed α component of the IgE receptor. However, phosphorylation of the 33,000 M(r) β component of the IgE receptor was not altered significantly by antigen stimulation. This suggests that the selective increase in phosphorylation of the IgE receptor α component may be part of the physiologic mediator secretion process triggered by antigen.
|Number of pages||4|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|Issue number||10 I|
|State||Published - Jan 1 1983|