Quantitation From Immunoprecipitation of hβc and Its Phosphorylation in Response to IL-3 From FDC-P1 Cells Expressing Full-Length and Truncated IL3Rα
| Receptor . | Total hβc in Immunoprecipitate . | Phosphorylated hβc . |
|---|---|---|
| IL-3Rα + hβc | 1.0 | 1.0 |
| IL-3RαΔNT + hβc | 0.86 | 0.36 |
| IL-3RαΔCT + hβc | 0.20 | <.005 |
| Receptor . | Total hβc in Immunoprecipitate . | Phosphorylated hβc . |
|---|---|---|
| IL-3Rα + hβc | 1.0 | 1.0 |
| IL-3RαΔNT + hβc | 0.86 | 0.36 |
| IL-3RαΔCT + hβc | 0.20 | <.005 |
Cells were cultured for 18 hours in the presence or absence of hIL-3 and the hβc immunoprecipitated with MoAb 4F3. Phosphoprotein in the immunoprecipitate was measured by PhosphorImager analysis of a Western blot using antiphosphotyrosine MoAb 3-365-10 (Boehringer Mannheim). hβc in the immunoprecipitate was quantitated by probing the Western blot with anti-hβc MoAb 1C1 followed by goat antimouse Ig coupled to horseradish peroxidase. Reactivity was detected by the chemiluminescence method using an ECL kit (Amersham) and quantitated by densitometric scanning of the x-ray film. Values are expressed relative to those of the full-length receptor.