Figure 2. Mis-regulation of domain-specific phosphorylation in CF.

A. SILAC ratios and differential PTMs of peptides across the CFTR sequence from 16HBE41o- and CFBE41o- cells. Data are representative of n=4 experiments. B. TMT-based quantification of phosphorylation of sites in ΔF508 CFTR relative to wild-type (wt) in 16HBE41o- and CFBE41o- cells. Values are log₂(ratio). non-mod, not modified; Phospho, phosphorylated; Me, methylated. Data are representative of n=7 experiments. C. Differential phosphorylation of Thr⁴²¹, Ser⁴²², Ser⁴²⁷ (RI element) and Ser⁶⁶⁰, Ser⁷⁰⁰, Ser⁸¹³ and Thr⁸¹⁶ (R-region) was confirmed by simultaneous detection of spiked-in synthetic heavy (¹³C₆¹⁵N₂ Lys; ¹³C₆¹⁵N₄ Arg)-labeled peptides in 16HBE41o- and CFBE41o- cells. Data are mean ± S.D. from n=5 independent biological replicates. *P < 0.0332, **P < 0.0021, ***P < 0.0002, and ****P < 0.0001 by unpaired, two-tailed t-tests, analyzed and corrected by the Bonferroni-Sidak method.