Basis of differentiation | Protein kinase A | Protein kinase C |
Definition | Protein kinase A is a protein kinase enzyme that is cyclic AMP dependent | Protein kinase C is a specific type of protein kinase enzyme that is responsive to lipid signaling |
Function | PKA is the end effector for different hormones that work through a cAMP signaling pathway | PKC responds to lipid signaling |
Substrate specificity | PKA primarily phosphorylates serine/threonine residues on target proteins | PKC phosphorylates serine/threonine residues but has a preference for targeting serine residues within specific circumstances (usually preceded by hydrophobic or acidic residues) |
Cellular localization | PKA is found in the cytoplasm of cells. It is localized to specific areas of the cell by interacting with A-kinase anchoring proteins | PKC can be found in different areas of the cell including the cytoplasm, plasma membrane, and other organelles |
Mechanism | PKA is regulated by cAMP levels, which determine its activation state | PKC is regulated by multiple complex mechanisms including DAG, Ca2+, protein-protein interactions, and phospholipids |