18. Development of a Reconstituted Assay to Test Casein Kinase 1δ Inhibitors to Block Alzheimer’s Disease Progression 

Neurofibrillary tangles (NFTs) are one of the pathological hallmarks of Alzheimer’s Disease (AD).  NFTs are primarily composed of hyperphosphorylated tau, which in its unphosphorylated state binds to and stabilizes the microtubule array in neurons.  It is believed that tau phosphorylation is then a predisposing event in the progression of AD.  Thus, the development of therapeutics that could inhibit the hyperphosphorylation of tau would potentially enable intervention to block the progression of AD.  Casein kinase 1δ (CK1δ) is upregulated in AD and is also able to phosphorylate tau on a number of residues that regulate tau’s affinity for microtubules, making CK1δ a prime candidate for therapeutic target.  We have taken an in silico approach to the design of competitive inhibitors of CK1δ using a napthoquinone molecule that inhibited CK1δ selectively over 100 other disease relevant kinases as a starting point for forward design and synthesis.  A series of resulting products were tested in a cellular assay and showed a dose-dependent decrease in tau phosphorylation via Western Blot of lysate from treated cells compared to untreated.  However, as tau can be phosphorylated by many cellular kinases, we wanted to determine if the decreased tau phosphorylation was directly due to inhibition of CK1δ by our compounds.  Thus, we have reconstituted tau phosphorylation by CK1δ in an in vitro assay using recombinantly expressed and purified components.  We have expressed human CK1δ and tau (4R) in bacteria and have purified them to >90% homogeneity.  We have shown that the tau protein is biologically active, as it shows standard, one-step binding affinity to microtubules in a pulldown assay.  We have developed and optimized our in vitro kinase assay and observe robust, CK1δ-dependent phosphorylation of tau that is blocked by known inhibitors of CK1δ.  This assay is now being used to test newly synthesized compounds designed to more effectively inhibit the kinase activity of CK1δ. 

  • Sabyasachi Chatterjee
  • Angel’Niqua Dixon
  • Linh Tran
  • Breyanah Graham
  • Jumia Callaway
  • Phong Huynh
  • Jayalakshmi Sridhar
  • Thomas Huckaba
  • Department of Biology & Department of Chemistry, Xavier University of Louisiana

Authors Participating In This Event

Sabyasachi Chatterjee

Research Scientists, Xavier University of LA

Research Scientists

Xavier University of LA