UASt regulatory sequences drive expression of HDAC4 in which the Mef2 binding site has been mutated (amino acid substitutions K165A, L168A and I172A) along with mutations within the nuclear localization signal (amino acid substitutions K245A, R247A, K249A, R255A, K256A, R266A, R267A). The coding sequence is tagged at the C-terminal end with 6xTag:MYC.