Mitochondrial dysfunction in Drosophila PINK1 mutants is complemented by parkin

Vol 441|29 June 2006|doi:10.1038/nature04788LETTERSMitochondrial dysfunction in Drosophila PINK1

mutants is complemented by parkinJeehye Park1,2*, Sung Bae Lee1,2*, Sungkyu Lee1,2, Yongsung Kim1,2, Saera Song1,2, Sunhong Kim1,2,

Eunkyung Bae3, Jaeseob Kim2,3, Minho Shong4, Jin-Man Kim5 & Jongkyeong Chung1,2Autosomal recessive juvenile parkinsonism (AR-JP) is an earlyonset form of Parkinsons disease characterized by motor disturbances and dopaminergic neurodegeneration1,2. To address its

underlying molecular pathogenesis, we generated and characterized

loss-of-function mutants of Drosophila PTEN-induced putative

kinase 1 (PINK1)3, a novel AR-JP-linked gene4. 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.The Drosophila PINK1 gene (also called CG4523) encodes a

polypeptide of 721 amino acids with a molecular mass of about 80

kDa (Fig. 1c and Supplementary Fig. S1a). Similar to human PINK1

(ref. 4), structural analysis of Drosophila PINK1 protein also revealed

two characteristic motifs: a mitochondrial targeting motif and a

serine/threonine kinase domain. The kinase domain exhibited 60%

similarity (42% identity) to that of human PINK1. Consistent with

the localization of human PINK1 (ref. 4), Drosophila PINK1 was also

found localized in mitochondria (Supplementary Fig. S1b, c).First, we observed the expression patterns of PINK1, and found

that its transcripts are ubiquitously expressed throughout all

developmental stages (Supplementary Fig. S1d). Its spatial

expression in adults was broadly distributed over all segments, but

was particularly higher in the thorax (Supplementary Fig. S1e). To

reveal in vivo roles of PINK1 in Drosophila, we generated PINK1 lossof-function mutant flies, PINK1D3 and PINK1B9, as well as revertants

(PINK1RV) (Fig. 1a), and these alleles were confirmed by conducting

Southern, northern and western blot analyses and genetic analysis

with PINK1 RNA-mediated interference lines (Supplementary

Fig. S1f, g, Fig. 1b, c and Supplementary Fig. S2, respectively).

PINK1 mutants...