Kinases are a major target for pharmacological intervention, and kinase inhibitors (both specific and promiscuous) represent important probes and drugs. Small molecule probes that target specific kinases represent critical tools for exploring and controlling cell function. The Cdc2-like kinases (Clk’s) and the dual-specificity tyrosine phosphorylation-regulated kinases (Dyrk’s) are two classes of enzymes that have been shown to phosphorylate specific proteins within the spliceosome; therefore, they are considered important targets for the modulation of gene splicing events. In addition to the agents reported in these reports, there is only one other reported Clk4 inhibitor, which was found to be somewhat promiscuous versus a kinase panel. Small molecule inhibitors of all 4 isoforms of the Clk family and both the Dyrk1A and Dyrk1B family, with varying selectivity profiles, will be of great utility to the study of these kinases as modulators of gene splicing, as well as other cellular events. The probe described here represents the first fully selective inhibitor of Cdc2-like kinase 4 (Clk4). This probe compound will be useful for the scientific community in unraveling the phenotype associated solely with Clk4 down-regulation without complication arising from the inhibition of related kinases. Particularly, given the reported role of the Clk family as a specific modulator of SR proteins, this probe will be useful in exploring the specific functions of Clk4 in terms of gene splicing.

1. PubChem link: qHTS for Inhibitors of CDC-like Kinase 4: Summary
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