Project: A preliminary atlas of OCNDS-associated variant specificity and identifying protein and phosphorylation changes in CK2 variants compared to isogenic controls

Lead Investigator: Daniel Schwartz, PhD | University of Connecticut

Grant Details:

Project funded for one year starting in 2026 for a total of $34,922.89.

The central goal of this project is to build an atlas of substrate specificity for variants in the CSNK2A1 gene, which lead to changes in the CK2 protein, and are associated with OCNDS. CK2 is a kinase, an enzyme that switches other proteins on and off, and its substrates are the proteins that it acts on. Substrate specificity refers to which proteins a kinase prefers to target. The atlas will serve as a reference map to show how each OCNDS-associated variant changes the way that CK2 chooses its targets. 

The first aim of the project is to build the atlas for 49 CSNK2A1 variants using ProPeL, a laboratory tool for measuring overall kinase activity and which sites on a protein a kinase prefers to modify. The variants will then be grouped based on how they change CK2 function and where they are in the protein, using existing information about the protein’s three-dimensional shape (Dr. Karsten Niefind) and enzymological properties (Dr. Joachim Jose). 

The groups will be based on each variant’s primary effect, such as 1) altered substrate specificity, a change in which proteins CK2 targets, 2) loss of catalytic activity, a reduced ability of the CK2 protein to carry out its functions as a kinase, or 3) changes in binding affinity, or how tightly CK2 binds to its partners. This grouping will allow researchers to investigate the mechanisms of OCNDS more precisely, variant by variant.

The second aim of this project is to identify differences in the proteome (the full collection of proteins in a cell) and the phosphoproteome (the map of which proteins have been switched on or off by phosphorylation, the attachment of a phosphate group) in OCNDS.

The initial study used to test this approach will focus on the K198R variant, which is found in ~33% of individuals with OCNDS. The phosphoproteome of cells carrying the K198R variant will be compared with that of control cells that do not carry the variant. If effective, this approach can then be repeated for additional variants.