Characterization of PINK1 (PTEN-induced Putative Kinase 1) Mutations Associated with Parkinson Disease in Mammalian Cells and Drosophila*

Saera Song,Seoyeon Jang,Jeehye Park,Sunhoe Bang,Sekyu Choi,Kyum-Yil Kwon,Xiaoxi Zhuang,Eunjoon Kim,Jongkyeong Chung

doi:10.1074/jbc.m112.430801

Abstract

Mutations in PINK1 (PTEN-induced putative kinase 1) are tightly linked to autosomal recessive Parkinson disease (PD). Although more than 50 mutations in PINK1 have been discovered, the role of these mutations in PD pathogenesis remains poorly understood. Here, we characterized 17 representative PINK1 pathogenic mutations in both mammalian cells and Drosophila. These mutations did not affect the typical cleavage patterns and subcellular localization of PINK1 under both normal and damaged mitochondria conditions in mammalian cells. However, PINK1 mutations in the kinase domain failed to translocate Parkin to mitochondria and to induce mitochondrial aggregation. Consistent with the mammalian data, Drosophila PINK1 mutants with mutations in the kinase domain (G426D and L464P) did not genetically interact with Parkin. Furthermore, PINK1-null flies expressing the transgenic G426D mutant displayed defective phenotypes with increasing age, whereas L464P mutant-expressing flies exhibited the phenotypes at an earlier age. Collectively, these results strongly support the hypothesis that the kinase activity of PINK1 is essential for its function and for regulating downstream Parkin functions in mitochondria. We believe that this study provides the basis for understanding the molecular and physiological functions of various PINK1 mutations and provides insights into the pathogenic mechanisms of PINK1-linked PD.

Highlights

Mutations in PINK1 cause recessive Parkinson disease
Selection of 17 PINK1 Mutations—To understand how Parkinson disease (PD)-linked mutations affect the function of PINK1 protein, we selected 17 missense mutations based on the high frequency of disease onset in patients carrying these mutations, the conservation of these amino acids in PINK1 across species, and the importance of these conserved residues in maintaining protein structure and PINK1 catalytic activity (Table 1) (6, 45–52)
A majority of PINK1 mutations are observed in the Ser/Thr kinase domain, suggesting that loss of the kinase activity plays a crucial part in the pathogenesis of PINK1-linked PD (Fig. 1A) (53–55)

Summary

Introduction

Mutations in PINK1 cause recessive Parkinson disease. Results: PINK1 mutations in the kinase domain hamper Parkin translocation to mitochondria, and their analogous mutations in Drosophila cannot rescue PINK1-null phenotypes. Significance: Understanding the roles of PINK1 mutations will be helpful for deciphering the pathogenic mechanism of PINK1-linked Parkinson disease. Mutations in PINK1 (PTEN-induced putative kinase 1) are tightly linked to autosomal recessive Parkinson disease (PD). We characterized 17 representative PINK1 pathogenic mutations in both mammalian cells and Drosophila. PINK1-null flies expressing the transgenic G426D mutant displayed defective phenotypes with increasing age, whereas L464P mutant-expressing flies exhibited the phenotypes at an earlier age. These results strongly support the hypothesis that the kinase activity of PINK1 is essential for its function and for regulating downstream Parkin functions in mitochondria. We believe that this study provides the basis for understanding the molecular and physiological functions of various PINK1 mutations and provides insights into the pathogenic mechanisms of PINK1-linked PD

Results

Discussion

Conclusion