Protein kinase A (PKA). which regulates a diverse set of biological functions downstream of cyclic AMP (cAMP). is a tetramer consisting of two catalytic subunits (PKA-C) and two regulatory subunits (PKA-R). When cAMP binds the PKA-R subunits. https://www.roneverhart.com/HP-Pavilion-15-eg2373cl-15-6-FHD-Touch-Laptop-Intel-Core-i7-1255U-3-50-GHz-GeForce-MX550-16GB-DDR4-512GB-SSD-Windows--p8309/