| Autor: |
Kazlauskaite, Agne, Martínez‐Torres, R Julio, Wilkie, Scott, Kumar, Atul, Peltier, Julien, Gonzalez, Alba, Johnson, Clare, Zhang, Jinwei, Hope, Anthony G, Peggie, Mark, Trost, Matthias, Aalten, Daan MF, Alessi, Dario R, Prescott, Alan R, Knebel, Axel, Walden, Helen, Muqit, Miratul MK |
| Zdroj: |
EMBO Reports; Aug2015, Vol. 16 Issue 8, p939-954, 16p |
| Abstrakt: |
Mutations in the mitochondrial protein kinase PINK1 are associated with autosomal recessive Parkinson disease ( PD). We and other groups have reported that PINK1 activates Parkin E3 ligase activity both directly via phosphorylation of Parkin serine 65 (Ser65)-which lies within its ubiquitin-like domain (Ubl)-and indirectly through phosphorylation of ubiquitin at Ser65. How Ser65-phosphorylated ubiquitin (ubiquitinPhospho-Ser65) contributes to Parkin activation is currently unknown. Here, we demonstrate that ubiquitinPhospho-Ser65 binding to Parkin dramatically increases the rate and stoichiometry of Parkin phosphorylation at Ser65 by PINK1 in vitro. Analysis of the Parkin structure, corroborated by site-directed mutagenesis, shows that the conserved His302 and Lys151 residues play a critical role in binding of ubiquitinPhospho-Ser65, thereby promoting Parkin Ser65 phosphorylation and activation of its E3 ligase activity in vitro. Mutation of His302 markedly inhibits Parkin Ser65 phosphorylation at the mitochondria, which is associated with a marked reduction in its E3 ligase activity following mitochondrial depolarisation. We show that the binding of ubiquitinPhospho-Ser65 to Parkin disrupts the interaction between the Ubl domain and C-terminal region, thereby increasing the accessibility of Parkin Ser65. Finally, purified Parkin maximally phosphorylated at Ser65 in vitro cannot be further activated by the addition of ubiquitinPhospho-Ser65. Our results thus suggest that a major role of ubiquitinPhospho-Ser65 is to promote PINK1-mediated phosphorylation of Parkin at Ser65, leading to maximal activation of Parkin E3 ligase activity. His302 and Lys151 are likely to line a phospho-Ser65-binding pocket on the surface of Parkin that is critical for the ubiquitinPhospho-Ser65 interaction. This study provides new mechanistic insights into Parkin activation by ubiquitinPhospho-Ser65, which could aid in the development of Parkin activators that mimic the effect of ubiquitinPhospho-Ser65. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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