UBA52 and Parkinson disease: Our findings in human Myc-α-synuclein transfected neurons, α-synuclein-PFFs treated SHSY5Y cells, rotenone-induced sporadic cellular and rat models of PD and SNCA transgenic mice highlight that UBA52 is downregulated during the early phase of sporadic PD, which is critical and might account for the reduction in proteasome activity during the pathological condition.