Roscovitine Targets, Protein Kinases and Pyridoxal Kinase

Abstract

(R)-Roscovitine (CYC202) is often referred to as a "selective inhibitor of cyclin-dependent kinases." Besides its use as a biological tool in cell cycle, neuronal functions, and apoptosis studies, it is currently evaluated as a potential drug to treat cancers, neurodegenerative diseases, viral infections, and glomerulonephritis. We have investigated the selectivity of (R)-roscovitine using three different methods: 1) testing on a wide panel of purified kinases that, along with previously published data, now reaches 151 kinases; 2) identifying roscovitine-binding proteins from various tissue and cell types following their affinity chromatography purification on immobilized roscovitine; 3) investigating the effects of roscovitine on cells deprived of one of its targets, CDK2. Altogether, the results show that (R)-roscovitine is rather selective for CDKs, in fact most kinases are not affected. However, it binds an unexpected, non-protein kinase target, pyridoxal kinase, the enzyme responsible for phosphorylation and activation of vitamin B 6 . These results could help in interpreting the cellular actions of (R)-roscovitine but also in guiding the synthesis of more selective roscovitine analogs.

Androgen receptor phosphorylation and stabilization in prostate cancer by cyclin-dependent kinase 1

“…We next carried out inhibitor studies to determine whether endogenous Cdk1 mediates AR Ser-81 phosphorylation in PCa cells. LNCaP cells were treated with DHT (10 nM) in the absence or presence of roscovitine, a selective inhibitor of cellular Cdks (Cdk1, Cdk2, Cdk5, Cdk7, and Cdk9) in the 1 to 10 M range (28,30,31). As shown in Fig.…”

Identifying the proteins to which small-molecule probes and drugs bind in cells

“…Although several key molecular targets have been identified through affinity chromatography (13)(14)(15), it has not been widely applied as a general solution to target identification for a number of reasons. It is often challenging to prepare SM affinity reagents that retain the desired cellular activity.…”

Le criblage à Roscoff

“…Sa faible toxicité et ses faibles effets secondaires sont le reflet d'une bonne sélectivité pharmacologique 3 . Des études ont montré que CDK1, -2, -5, -7 et -9 sont les protéine kinases les plus sensibles à la molécule [8]. Ainsi, exploitée par la société Cyclacel (Berkeley Heights, New Jersey, États-Unis) sous le nom de Seliciclib ou CYC202, elle a notamment atteint la phase 2 d'études cliniques pour le traitement du cancer du poumon non à petites cellules et, plus récemment, de la maladie de Cushing, dont les résultats sont attendus en 2017 4 .…”

“…La sélectivité pharmacologique de l'hymenialdisine, ainsi que celle d'autres inhibiteurs caractérisés à Roscoff (dont la roscovitine [8] et l'aloisine [16]), a été étudiée par chromatographie d'affinité (fonctionnalisation des structures représentée sur la Figure 2). Cette étude est cruciale pour mieux appréhender, voire expliquer, certains effets secondaires observables lors d'une utilisation chez l'homme (pour revue voir [17]).…”