TY - JOUR T1 - Cushing’s Syndrome mutant PKA<sup>L205R</sup> exhibits altered substrate specificity JF - bioRxiv DO - 10.1101/091231 SP - 091231 AU - Joshua M. Lubner AU - Kimberly L. Dodge-Kafka AU - Cathrine R. Carlson AU - George M. Church AU - Michael F. Chou AU - Daniel Schwartz Y1 - 2016/01/01 UR - http://biorxiv.org/content/early/2016/12/05/091231.abstract N2 - The PKAL205R hotspot mutation has been implicated in Cushing’s Syndrome through hyperactive gain-of-function PKA signaling, however its influence on substrate specificity has not been investigated. Here, we employ the Proteomic Peptide Library (ProPeL) approach to create high-resolution models for PKAWT and PKAL205R substrate specificity. We reveal that the L205R mutation reduces canonical hydrophobic preference at the substrate P+1 position, and increases acidic preference in downstream positions. Using these models, we designed peptide substrates that exhibit altered selectivity for specific PKA variants, and demonstrate the feasibility of selective PKAL205R loss-of-function signaling. Through these results, we suggest that substrate rewiring may contribute to Cushing’s Syndrome disease etiology, and introduce a powerful new paradigm for investigating mutation-induced kinase substrate rewiring in human disease. ER -