Accumulation of GluK2 in the plasma membrane of PD neurons has been shown to be due to slowed GluK2 turnover caused by the loss of parkin protein (ubiquitin E3 ligase that breaks down unnecessary proteins by tagging the damaged and excess proteins with a molecule called ubiquitin), which interacts with the C-terminal tail of GluK2 and is able to ubiquitinate it (Maraschi et al., 2014). This evidence concerns the gene GRIK2 and Parkinson disease.