Toxoplasma DJ-1 Regulates Organelle Secretion by a Direct Interaction with Calcium-Dependent Protein Kinase 1

Authors

Matthew A. Child, Stanford University and Imperial College LondonFollow
Megan Garland, Stanford UniversityFollow
Ian Foe, Stanford UniversityFollow
Peter Madzelan, University of Nebraska-LincolnFollow
Moritz Treeck, Stanford University School of Medicine and National Institute for Medical Research, London, UKFollow
Wouter A. van der Linden, Stanford UniversityFollow
Kristina Oresic Bender, Stanford UniversityFollow
Evanthie Weerapana, Boston CollegeFollow
Mark A. Wilson, University of Nebraska-LincolnFollow
John C. Boothroyd, Stanford University School of MedicineFollow
Michael L. Reese, Stanford University School of Medicine and University of Texas Southwestern Medical CenterFollow

Date of this Version

2017

Citation

Child MA, Garland M, Foe I, Madzelan P, Treeck M, van der Linden WA, Oresic Bender K, Weerapana E, Wilson MA, Boothroyd JC, Reese ML, Bogyo M. 2017. Toxoplasma DJ-1 regulates organelle secretion by a direct interaction with calcium-dependent protein kinase 1. mBio 8:e02189-16.

Comments

© 2017 Child et al. This is an openaccess article distributed under the terms of the Creative Commons Attribution 4.0 International license.

Abstract

Human DJ-1 is a highly conserved and yet functionally enigmatic protein associated with a heritable form of Parkinson’s disease. It has been suggested to be a redox-dependent regulatory scaffold, binding to proteins to modulate their function. Here we present the X-ray crystal structure of the Toxoplasma orthologue Toxoplasma gondii DJ-1 (TgDJ-1) at 2.1-A resolution and show that it directly associates with calcium-dependent protein kinase 1 (CDPK1). The TgDJ-1 structure identifies an orthologously conserved arginine dyad that acts as a phospho-gatekeeper motif to control complex formation. We determined that the binding of TgDJ-1 to CDPK1 is sensitive to oxidation and calcium, and that this interaction potentiates CDPK1 kinase activity. Finally, we show that genetic deletion of TgDJ-1 results in upregulation of CDPK1 expression and that disruption of the CDPK1/TgDJ-1 complex in vivo prevents normal exocytosis of parasite virulence-associated organelles called micronemes. Overall, our data suggest that TgDJ-1 functions as a noncanonical kinase-regulatory scaffold that integrates multiple intracellular signals to tune microneme exocytosis in T. gondii.