Fig. 5.

Subcellular phosphatase assays are sensitive to specific classes of phosphatase inhibition. A–F, Phosphosubstrates were incubated with AC16-CAR SE (black bars) or NE (gray bars) fractions and the pan phosphatase inhibitor NaPP (10 mm), the Tyr phosphatase inhibitor Na₃VO₄ (200 μm), the Ser/Thr phosphatase inhibitor microcystin-LR (MCLR, 1 μg/ml), or control (NoTx). NE fractions used for phospho-CREB (B, gray bars) and phospho-MK2 (C, gray bars) were collected from cells stimulated with TNF for 30 min. Cellular equivalents for each assay are listed in supplemental Table S2. Data are shown as the means ± standard error of n = 8 (NoTx) or 4 (NaPP, Na₃VO₄, MCLR) assay replicates. N. D., not detectable above baseline. Fraction-specific sensitivity differences were assessed by two-tailed Student's t test with Bonferroni correction.