Extended Data Figure 9.

MrgprB2^MUT mast cells are unresponsive to basic secretagogues and various therapeutic drugs.

a. Example traces showing changes in [Ca2+]_i, as measured by Fluo-4 imaging, from WT and MrgprB2^MUT peritoneal mast cells induced by the basic secretagogues from Figure 2e. Each trace is a response from a unique cell.

b. Representative Fluo-4 images (left) and fluorescence traces (right) from WT (top) and MrgprB2^MUT (bottom) cultured peritoneal mast cells during application of icatibant (50 μg/ml).

c. Example traces showing changes in [Ca2+]_i, as measured by Fluo-4 imaging, from WT and MrgprB2^MUT peritoneal mast cells induced by selected FDA-approved cationic peptidergic drugs. Each trace is a response from a unique cell.

d. Representative Fluo-4 images (left) and fluorescence traces (right) from WT (top) and MrgprB2^MUT (bottom) cultured peritoneal mast cells during application of atracurium (50 μg/ml).

e. Representative Fluo-4 images (left) and fluorescence traces (right) from WT (top) and MrgprB2^MUT (bottom) cultured peritoneal mast cells during application of ciprofloxacin (200 μg/ml).