A study in PINK1

The kinase enzyme PINK1 is known mainly for two reasons. At an organism level, mutations of PINK1 have been associated with autosomal-recessive juvenile Parkinsonism (AR-JP). At a cellular level, PINK1 phosphorylates both ubiquitin and a ubiquitin-like domain within its partner enzyme Parkin to trigger mitophagy, the process by which cells get rid of dysfunctional mitochondria. David Komander and co-authors report the structure of a complex between louse PINK1 and ubiquitin, which they obtained using nanobody-based stabilization. The structure provides molecular insights not only into PINK1–ubiquitin interactions and therefore the mechanism of PINK1 activity, but also into AR-JP-associated mutations, some of which disrupt ubiquitin binding.