GRIN2B and Huntington disease: In addition, reduced transcription of the GluN2B gene and proteolysis of the subunit by calpains in HD alter the functional characteristics of the striatal NMDARs [127], while altered interaction of mHtt with the scaffolding protein PSD95 and tyrosine phosphorylation of NMDARs further sensitizes the receptors to glutamate [110,128].