Novel Insights into the Beneficial and Detrimental Actions of Cdk5

Cdk5 protein regulates calpain-directed degradation of the NMDA receptor subunit NR2B. p35-Cdk5 binds calpain, which then degrades NR2B. The degradation of NR2B does not occur in the absence of Cdk5 protein. Smaller arrow (found in conditions where Cdk5 is present) indicates diminished signaling through NMDA receptors; absence of NR2B subunits precludes signaling by these receptors. Thus, the overall signal transduced by the total number of ligand-bound NMDA receptors is reduced.”