Structure-guided mutagenesis reveals a hierarchical mechanism of Parkin activation.
Matthew Y TangMarta VranasAndrea I KrahnShayal PundlikJean-François TrempeEdward A FonPublished in: Nature communications (2017)
Parkin and PINK1 function in a common pathway to clear damaged mitochondria. Parkin exists in an auto-inhibited conformation stabilized by multiple interdomain interactions. The binding of PINK1-generated phospho-ubiquitin and the phosphorylation of the ubiquitin-like (Ubl) domain of Parkin at Ser65 release its auto-inhibition, but how and when these events take place in cells remain to be defined. Here we show that mutations that we designed to activate Parkin by releasing the Repressor Element of Parkin (REP) domain, or by disrupting the interface between the RING0:RING2 domains, can completely rescue mutations in the Parkin Ubl that are defective in mitochondrial autophagy. Using a FRET reporter assay we show that Parkin undergoes a conformational change upon phosphorylation that can be mimicked by mutating Trp403 in the REP. We propose a hierarchical model whereby pUb binding on mitochondria enables Parkin phosphorylation, which, in turn, leads to REP removal, E3 ligase activation and mitophagy.
Keyphrases
- oxidative stress
- crispr cas
- induced apoptosis
- small molecule
- protein kinase
- signaling pathway
- endoplasmic reticulum stress
- molecular dynamics simulations
- high throughput
- molecular dynamics
- cell proliferation
- reactive oxygen species
- cell cycle arrest
- sensitive detection
- crystal structure
- nlrp inflammasome
- energy transfer