Casein kinase I isoform delta (CSNK1D) (CSNK1D)

Casein kinase I isoform delta (CK1 delta) is a member of the highly conserved serine/threonine protein kinase family that plays a pivotal role in regulating the eukaryotic circadian clock (UniProt: P48730). It phosphorylates Period proteins (PER1, PER2, and PER3), marking them for ubiquitination and proteasomal degradation, which is essential for maintaining the ~24-hour rhythm (Toh et al., Science, 2001). Beyond chronobiology, CK1 delta is involved in diverse cellular processes including DNA damage repair, Wnt/beta-catenin signaling, and microtubule dynamics (Knippschild et al., Cell Signal, 2005). Dysregulation of this kinase is linked to various pathologies; for instance, mutations in the CSNK1D gene cause Familial Advanced Sleep Phase Syndrome (FASPS), while its overexpression is observed in several cancers, including breast, pancreatic, and colon cancer (Cheong & Virshup, J Biochem, 2011). In neurodegenerative diseases like Alzheimer's and ALS, CK1 delta is implicated in the pathological phosphorylation of tau and TDP-43 (Xu et al., Int J Mol Sci, 2019). Pharmacological targeting of CK1 delta focuses on small-molecule inhibitors that compete for the ATP-binding pocket, such as PF-670462, though achieving selectivity over the closely related CK1 epsilon isoform remains a significant therapeutic challenge (Janovska et al., Br J Pharmacol, 2020).

Other names

CK1 deltaCK1dCasein kinase 1 deltaHCKIDSerine/threonine-protein kinase Casein kinase I isoform delta

ATP-competitive inhibition of the kinase domain to prevent phosphorylation of downstream substrates such as PER proteins and p53 (Janovska et al., Br J Pharmacol, 2020).