Mouse Anti-Bacteria PKA-R Monoclonal antibody. In cell biology, Protein kinase A (PKA) refers to a family of enzymes whose activity is dependent on cellular levels of cyclic AMP (cAMP). PKA is also known as cAMP-dependent protein kinase (EC 2.7.11.11). Protein kinase A has several functions in the cell, including regulation of glycogen, sugar, and lipid metabolism. It should neither be confused with AMP-activated protein kinase-which, although being of similar nature, may have opposite effect -nor with cyclin-dependent kinases (Cdks).