L166P mutant DJ-1 promotes cell death by dissociating Bax from mitochondrial Bcl-XL
Department of Pharmacology, Laboratory of Molecular Neuropathology, Soochow University College of Pharmaceutical Sciences, Suzhou, Jiangsu, 215123, People’s Republic of China
Molecular Neurodegeneration 2012, 7:40 doi:10.1186/1750-1326-7-40Published: 14 August 2012
Mutations or deletions in DJ-1/PARK7 gene are causative for recessive forms of early onset Parkinson’s disease (PD). Wild-type DJ-1 has cytoprotective roles against cell death through multiple pathways. The most commonly studied mutant DJ-1(L166P) shifts its subcellular distribution to mitochondria and renders cells more susceptible to cell death under stress stimuli. We previously reported that wild-type DJ-1 binds to Bcl-XL and stabilizes it against ultraviolet B (UVB) irradiation-induced rapid degradation. However, the mechanisms by which mitochondrial DJ-1(L166P) promotes cell death under death stimuli are largely unknown.
We show that DJ-1(L166P) is more prone to localize in mitochondria and it binds to Bcl-XL more strongly than wild-type DJ-1. In addition, UVB irradiation significantly promotes DJ-1(L166P) translocation to mitochondria and binding to Bcl-XL. DJ-1(L166P) but not wild-type DJ-1 dissociates Bax from Bcl-XL, thereby leading to Bax enrichment at outer mitochondrial membrane and promoting mitochondrial apoptosis pathway in response to UVB irradiation.
Our findings suggest that wild-type DJ-1 protects cells and DJ-1(L166P) impairs cells by differentially regulating mitochondrial Bax/Bcl-XL functions.