Figure 3.

Block of CTLA4 synthesis. (A) A single experimental data point was compared to the theoretical value in Eq. S21. CTLA4 molecules in the cytoplasm can transiently compensate CTLA4 loss on the plasma membrane after the block of synthesis. However, both pools become exhausted with extended exposure to CHX. (B) In silico experiment of blocked synthesis with additional depletion of cytoplasmic CTLA4 (R_c,0 = 0) or block of recycling (k_r = 0). These curves are obtained by numerical solution of the trafficking model in Eq. S1. In the absence of cytoplasmic CTLA4 or of the recycling process, the surface CTLA4 clears quickly, reducing by 50% within ∼2.41 and 2.32 min, respectively.