Programmable RNA editing enables reversible recoding of RNA information for research and disease treatment. Previously, we developed a programmable A to I RNA editing approach by fusing catalytically inactivated RNA-targeting CRISPR-Cas13 (dCas13) with the adenine deaminase domain of ADAR2. Here, we report a C to U RNA editor, referred to as RNA Editing for Specific C to U Exchange (RESCUE), by directly evolving ADAR2 into a cytidine deaminase. RESCUE doubles the number of pathogenic mutations targetable by RNA editing and enables modulation of phospho-signaling-relevant residues. We apply RESCUE to drive β-catenin activation and cellular growth. Furthermore, RESCUE retains A to I editing activity, enabling multiplexed C to U and A to I editing through the use of tailored guide RNAs.