... this hypothesis, weexamined the effect of IC261, a kinase inhibitor of CK1ε, in cell culture. IC261 was reported to selectively inhibit caseinkinase 1 compared to other protein kinases, by an ... CRYPTO-CHROME [24]. These clock proteins are also reported toregulate the cell cycle, suggesting they have a role in linking the circadian system and the cell cycle machinery [25,26].Mammalian ... isoforms of PERIOD proteinsand two isoforms of CRYPTOCHROME proteins, which areencoded by PER1, PER2, PER3, CRY1 and CRY2 genes,respectively. In order to define the role of each isoform in CK1ε-mediated...