Poster Presentation The 47th Lorne Conference on Protein Structure and Function 2022

Activation mechanism of PINK1 (#148)

Zhong Yan Gan 1 , Sylvie Callegari 1 , Simon A Cobbold 1 , Thomas R Cotton 1 , Michael Mlodzianoski 1 , Alexander F Schubert 2 , Niall D Geoghegan 1 , Kelly L Rogers 1 , Andrew Leis 1 , Grant Dewson 1 , Alisa Glukhova 1 3 4 , David Komander 1
  1. Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
  2. Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
  3. Drug Discovery Biology, Monash Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
  4. Department of Biochemistry and Pharmacology, The University of Melbourne, Melbourne, VIC, Australia

Inherited forms of Parkinson’s disease (PD) account for approximately 10% of PD cases and are linked to mutations in ~15 PARK genes. Mutations in the kinase PINK1 (PARK6) and the E3 ubiquitin ligase Parkin (PARK2) account for a subset of inherited PD cases. Both proteins function in the autophagic clearance of damaged mitochondria, a process known as mitophagy.

PINK1 is a mitochondrial damage sensor. Under basal conditions, PINK1 is rapidly turned over, whereas when mitochondria are damaged, PINK1 is stabilised on the mitochondrial surface and activated by autophosphorylation. Activated PINK1 is able to phosphorylate ubiquitin and the ubiquitin-like domain of Parkin, initiating mitophagy. Previous structural analysis of phosphorylated and ubiquitin bound Pediculus humanus corporis (Ph)PINK1 explained how PINK1 engages and phosphorylates ubiquitin [1], but the mechanism of PINK1 activation remained unclear.

We have elucidated the activation mechanism of PINK1 by X-ray crystallography and cryo-EM [2]. A crystal structure of unphosphorylated PhPINK1 resolves a previously omitted N-terminal helix revealing how PINK1 is oriented on mitochondria. We further reveal a 2.35 Å cryo-EM structure of a symmetric PhPINK1 dimer trapped in the process of trans-autophosphorylation, and a 3.1 Å cryo-EM structure of phosphorylated PhPINK1 undergoing a conformational change to become an active ubiquitin kinase. Our work delineates the complete activation mechanism of PINK1 and illuminates how PINK1 is positioned on the mitochondrial outer membrane.

  1. Schubert, A.F., Gladkova, C., Pardon, E., Wagstaff, J.L., Freund, S.M., Steyaert, J., Maslen, S.L. and Komander, D. (2017). Structure of PINK1 in complex with its substrate ubiquitin. Nature, 552(7683), 51-56.
  2. Gan, Z.Y., Callegari, S., Cobbold, S.A., Cotton, T.R., Mlodzianoski M., Schubert, A.F., Geoghegan, N.D., Rogers, K.L., Leis, A., Dewson, G., Glukhova, A. and Komander, D. (2021). Activation mechanism of PINK1. Nature.