Meta-Biol

• Pathways

PKC contains a N-terminal C2 like domain, a pseudosubstrate (PS), DAG binding (C1) domain and a C-terminal kinase domain. The PS sequence resembles an ideal substrate with the exception that it contains an alanine residue instead of a substrate serine residue. It is bound to the kinase domain in the resting state. As a result, PKC is maintained in a closed inactive state, inaccessible to cellular substrates. On stimulation of receptors there is an increase in intracellular calcium and diacylglycerol (DAG) levels which leads to the activation of PKC and its translocation from the cytosol to the plasma membrane. PKCs tether to the plasma membrane through DAG binding to the C1 domain. This confers a high-affinity interaction between PKC and the membrane, leading to a massive conformational change that releases the PS domain from the catalytic site, the system becomes both competent and accessible (Colon-Gonzalez & Kazanietz 2006).