Elevated synaptic PKA activity and abnormal striatal dopamine signaling in Akap11 mutant mice, a genetic model of schizophrenia and bipolar disorder [bulkSeq]

Loss-of-function mutations in AKAP11 (a protein kinase A (PKA)-binding protein) greatly increase the risk of bipolar disorder and schizophrenia. To determine the neurobiological functions of AKAP11 and the consequences of its absence, we conducted multi-omic analyses of Akap11 mutant mouse brains. We find that AKAP11 is a key regulator of PKA proteostasis in the brain whose loss leads to dramatically elevated PKA expression and phosphorylation, especially in synapses. Transcriptomic analysis shows extensive gene expression changes throughout the brain, including prominent decreases in synapse-related genes sets. Gene expression is especially affected in spiny projection neurons of the striatum, a brain region implicated in motivation, cognition and psychiatric disorders. In vivo, real-time measurements of PKA activity in ventral striatum of Akap11-/- mice revealed constitutively elevated kinase activity, which distorts dopamine to PKA signaling. Our work reveals the molecular basis of circuit dysfunction in a genetically valid model of psychotic disorder.