Epiblastin A

Epiblastin A inhibit casein kinase 1 (CK1) isoforms with half maximal inhibitory concentration (IC50) values of 33.5 μM, 6.9 μM, and 30.4 μM for CK1α, CK1δ, and CK1ɛ isoforms, respectively. Selectivity analysis revealed that it further inhibits brain-selective kinase 1 (BRSK1; IC50 = 24.2 ± 5.8 μM), eukaryotic elongation factor 2 kinase (EEF2K; IC50 = 27.4 ± 5.6 μM), epidermal growth factor receptor kinase (EGFR; IC50 = 8.3 ± 1.5 μM), Map kinase-interacting Ser/Thr kinase 2 (MKNK2; IC50 = 45.0 ± 10.3 μM), and receptor-interacting Ser/Thr kinase 2 (RIPK2; IC50 = 38.0 ± 11.3 μM). Given the low potency and poor selectivity we consider Epiblastin A an Historical Compound and we do not suggest its use to interrogate target activity in cells.