Electronic Thesis and Dissertation Repository


Master of Science




David Litchfield


CK2 is a constitutively active, ubiquitously expressed and pleiotropic serine/threonine protein kinase that is implicated in many cellular functions including tumorigenesis. CK2 has two catalytic subunits, CK2a and CK2a’, that carry out its function in the cell. Previous studies have indicated that inhibitor-refractory mutants have been effective in recovering residual CK2 activity, in the presence of inhibitors, when compared to wild type CK2. Based on these observations, inhibitor-refractory mutants were created for both CK2a and CK2a’ and tested with various concentrations with two CK2-specific inhibitors, CX-4945 and inhibitor VIII. The CK2a triple mutant (V66A/I174A/H160D) was tested in inducible U2OS Flp-In cell lines with inhibitor VIII and CX-4945 inhibitors and was found to recover residual CK2 activity 5-fold greater than previously established CK2a-(V66A/I174A) inhibitor-refractory mutants. Seven novel mutations were made to CK2a’ in vitro and tested with CK2 inhibitor CX-4945. The mutants that recovered the most residual CK2 activity were introduced into stable cell lines and tested with the same conditions as the CK2a catalytic subunit. Generation of inhibitor-refractory mutants for both catalytic subunits of CK2 will provide insight into the distinct functions, interactions with inhibitors and ability to recover activity of the two catalytic subunits of CK2.