Catalytic Subunit of PKA as a Prototype of the Eukaryotic Protein Kinase Family.

The catalytic subunit of protein kinase A (PKAc) is conserved in all eukaryotic protein kinases. PKAc consists of two lobes that form the catalytic cleft containing the ATP-binding, peptide-binding site, and catalytic sites. During folding, PKAc secondary structures organize so that the non-polar regions form a globular core, while mobile loops and tails are exposed and can act as regulatory elements.

[Effect of etimizole structural analogues on protein kinase CK2, protein phosphorylation and transcription of chromatin in rat brain cortex and hippocampus].

Protein kinase CK2 is an important enzyme in the nervous system. The nuclear forms of CK2 regulate chromatin structure and gene expression, the key processes for long-term memory formation. Memory modulators, the Structural Analogues of Etimizole (SAE), were able to increase or decrease the activity of chromatin-associated CK in the cortex and hippocampus of rat brain in vitro.

[Ethymisole: reassessing and old drug].

Ethymisole, or 4,5-di(N-methylcarbamoyl)-1-ethyl-imidazole, is a cognitive enhancer and nootropic drug, the molecular target of which is a multifunctional protein kinase C K2 (casein kinase II). New data about signal pathways and protein substrates of CK2 have been obtained due to research effort of many laboratories. The paper presents a historical sketch of molecular investigations underlying memory enhancer effects of ethymisole; this and the other pharmacological effects of ethymisole are considered in the light of new data.

Status of the "protein kinase CK2-HMG14" system in age-related amnesia in rats.

The experiments described here demonstrate that disruption of the phosphorylation of transcription factors of the HMG cAMP/Ca-independent protein kinase CK2 class may be the cause of decreased gene expression in age-related cognitive deficits. Amnesia for a conditioned passive avoidance reaction (CPAR) in aged rats (24 months old) was accompanied by decreases in the synthesis of synaptosomal proteins and transcription in nuclei isolated from cortical, hippocampal, and striatal neurons. There was a decrease in chromatin protein kinase CK2 activity and a significant decrease in the phosphorylation of HMG14 by protein kinase CK2.