The function of PRNP (prion protein (Kanno blood group), Ensembl gene identifier ENSG00000171867) is as follows. Its primary physiological function is unclear. May play a role in neuronal development and synaptic plasticity. May be required for neuronal myelin sheath maintenance. May promote myelin homeostasis through acting as an agonist for ADGRG6 receptor. May play a role in iron uptake and iron homeostasis. Soluble oligomers are toxic to cultured neuroblastoma cells and induce apoptosis (in vitro) (By similarity). Association with GPC1 (via its heparan sulfate chains) targets PRNP to lipid rafts. Also provides Cu(2+) or Zn(2+) for the ascorbate-mediated GPC1 deaminase degradation of its heparan sulfate side chains (By similarity). {ECO:0000250|UniProtKB:P04925, ECO:0000269|PubMed:12732622, ECO:0000269|PubMed:19936054, ECO:0000269|PubMed:20564047, ECO:0000305}.