Proximity biotinylation to define the local environment of the protein kinase A catalytic subunit in adrenal cells

Mutant protein kinase A catalytic subunit (PKAc) drives adrenal Cushing's syndrome, though its signaling interactions remain unclear. This protocol details steps to use livecell proximity labeling to identify subcellular compartments and proteins closely associated with variants of PKAc in human adrenal cells. We include instructions for clonal cell line generation, live biotin labeling of proximal proteins, isolation of biotinylated proteins, and sample processing for proteomic analysis using the biotin ligase miniTurbo with wildtype and mutant PKAc.1, 2 For complete details on the use and execution of this protocol, please refer to Omar et al. (2022).3