Vx 745

The ERK1/2 inhibitor PD184352 was from Axon and was used at a final concentration of 2 μm. The p38 inhibitor VX-745 was from Selleck and was used at a final concentration of 1 μm. The PI3K inhibitor GDC-0941 was from Axon and was used at a final concentration of 1 μm. The MK2/3 inhibitor PF3644022 was from Tocris and was used at a final concentration of 5 μm. These concentrations were used because they have previously been established to inhibit the target kinases in cultured cells (50 (link), 66 (link), 67 (link)). The N-terminal MSK1/2 inhibitor SB747651A, which also inhibits RSK, was from Axon and was used at a final concentration of 10 μm. The C-terminal RSK/MSK1/2 inhibitor compound 20 (51 (link)) was generated in-house and was used at a final concentration of 10 μm. The RSK inhibitor LJI308 (47 (link), 48 (link)) was also generated in-house and was used at a final concentration of 10 μm unless otherwise stated. The selectivity of PD184352, VX745, and SB747641 has been published previously (33 (link), 50 (link), 66 (link)). The selectivity of LJI308 is given in Fig. S2. The CREB–CBP interaction inhibitor Naphthol AS-E (CAS 92-78-4) was from Calbiochem and used at 20 μm.

PD0325901 (0.1 μM; pre‐treatment for 10 min) was produced by the Division of Signal Transduction Therapy (DSTT), University of Dundee. VX‐745 (1 μM; pre‐treatment for 1 h) was purchased from Selleckchem. C34 (10 μM; pre‐treatment for 1 h) was from MedChemExpress. Leupeptin (100 μg/ml; pre‐treatment for 1 h) and bafilomycin A1 (1 μM; pre‐treatment for 15 min) were purchased from Sigma‐Aldrich. Lipopolysaccharide (LPS) from Salmonella minnesota R595 was from Enzo Life Sciences.