CLPP and Parkinson disease: In 2019, Hu et al. found that adenosine triphosphate- (ATP-) dependent Clp protease (ClpP), a mitochondrial matrix protease, suppresses the phosphorylation of α-synuclein Ser129 to promote neuronal morphology of neurons derived from PD patients carrying the α-synuclein A53T mutant [10].