Mitochondrial dysfunction in Drosophila PINK1 mutants is complemented by parkin.
Autosomal recessive juvenile parkinsonism (AR-JP) is an early-onset form of Parkinson's disease characterized by motor disturbances and dopaminergic neurodegeneration. To address its underlying molecular pathogenesis, we generated and characterized loss-of-function mutants of Drosophila PTEN-induced putative kinase 1 (PINK1), a novel AR-JP-linked gene. Here, we show that PINK1 mutants exhibit indirect flight muscle and dopaminergic neuronal degeneration accompanied by locomotive defects. Furthermore, transmission electron microscopy analysis and a rescue experiment with Drosophila Bcl-2 demonstrated that mitochondrial dysfunction accounts for the degenerative changes in all phenotypes of PINK1 mutants. Notably, we also found that PINK1 mutants share marked phenotypic similarities with parkin mutants. Transgenic expression of Parkin markedly ameliorated all PINK1 loss-of-function phenotypes, but not vice versa, suggesting that Parkin functions downstream of PINK1. Taken together, our genetic evidence clearly establishes that Parkin and PINK1 act in a common pathway in maintaining mitochondrial integrity and function in both muscles and dopaminergic neurons.
Park
Jeehye
J
Lee
Sung Bae
SB
Lee
Sungkyu
S
Kim
Yongsung
Y
Song
Saera
S
Kim
Sunhong
S
Bae
Eunkyung
E
Kim
Jaeseob
J
Shong
Minho
M
Kim
Jin-Man
JM
Chung
Jongkyeong
J