Classical anticytokinins do not interact with cytokinin receptors but inhibit cyclin-dependent kinases.

摘要: Cytokinins are a class of plant hormones that regulate the cell cycle and diverse developmental physiological processes. Several compounds have been identified antagonize effects cytokinins. Based on structural similarities competitive inhibition, it has assumed these anticytokinins act through common cellular target, namely cytokinin receptor. Here, we examined directly possibility various representative classical inhibit Arabidopsis receptors CRE1/AHK4 (cytokinin response 1/Arabidopsis histidine kinase 4) AHK3 (Arabidopsis 3). We show pyrrolo[2,3-d]pyrimidine pyrazolo[4,3-d]pyrimidine do not as competitors cytokinins at receptor level. Flow cytometry microscopic analyses revealed cause disorganization microtubular cytoskeleton apoptosis. This is consistent with hypothesis they regulatory cyclin-dependent (CDK) enzymes. Biochemical studies demonstrated inhibition by selected anti-cytokinins both human CDKs. X-ray determination crystal structure CDK2-anticytokinin complex antagonist occupies ATP-binding site CDK2. Finally, treatment cancer lines their ability to kill cells similar effectiveness known CDK inhibitors.