Nr4a3 suppresses the levels of tryptase protein and enzymatic activity.

<p>(A) Whole cell lysates from WT and Nr4a3<sup>−/−</sup> mast cells were prepared and analyzed by Western blot for mMCP-6 and CPA3 as indicated (the upper and lower panels represent individual analyses, performed on the same membrane that was stripped of protein between analyses). The absence of Nr4a3 results in increased levels of mMCP-6 but does not affect CPA3. (B) Quantification of band intensities for mMCP-6 showing a significant increase in mMCP-6 protein in the absence of Nr4a3. (n = 4; *p≤0.05). The level of mMCP-6 and CPA3 proteins were quantified and compared against b-actin followed by normalization using the average signal from WT samples set to 1. (C) Whole cell lysates from WT and Nr4a3<sup>−/−</sup> mast cells were prepared and analyzed for trypsin-like activity using the chromogenic substrate S-2288. Note that the absence of Nr4a3 results in increased trypsin-like enzymatic activity. (T-test, n = 4; *p≤0.05).</p>