Mitochondrial membrane potential decrease caused by loss of PINK1 is not due to proton leak, but to respiratory chain defects.
Amo T, Sato S, Saiki S, Wolf AM, Toyomizu M, Gautier CA, Shen J, Ohta S, Hattori N. Mitochondrial membrane potential decrease caused by loss of PINK1 is not due to proton leak, but to respiratory chain defects. Neurobiol Dis. 2011 Jan; 41(1):111-8.