Fig. 1.
Roscovitine and CR8 interact with casein kinase 1 (CK1) isoforms. A: chemical structure of (R)-roscovitine and (S)-CR8. B: interaction scores and Kd values for roscovitine and CR8 with various kinases (DiscoveRx). Roscovitine and CR8 were tested at a 10-µM concentration on an 8-kinase interaction panel. A semiquantitative scoring of this primary screen was obtained. This score relates to a probability of a hit rather than strict affinity. Scores >10, between 1 and 10, and <1 indicate that the probability of a being a false positive is <20, <10, and <5%, respectively. Kd values were calculated from dose-response curves. nt, not tested. C: roscovitine inhibits the catalytic activity of CDKs and CK1s. Each kinase was assayed in vitro in the presence of a range of roscovitine concentrations. IC50 values were determined from the dose-response curves.