Molecular mechanism for the subversion of the retromer coat by the Legionella effector RidL
The work by Romano-Moreno et al. uncovers the molecular mechanism by which retromer, one of the major sorting machineries on endosomes, is targeted by the Legionella pneumophila effector RidL (in pink color)
Romano-Moreno M, Rojas AL, Williamson CD, Gershlick DC, Lucas M, Isupov MN, Bonifacino JS, Machner MP, Hierro A.
Proc Natl Acad Sci U S A 2017 Dec; 114: E11151.
Microbial pathogens employ sophisticated virulence strategies to cause infections in humans. The intracellular pathogen Legionella pneumophila encodes RidL to hijack the host scaffold protein VPS29, a component of retromer and retriever complexes critical for endosomal cargo recycling. Here, we determined the crystal structure of L. pneumophila RidL in complex with the human VPS29-VPS35 retromer subcomplex. A hairpin loop protruding from RidL inserts into a conserved pocket on VPS29 that is also used by cellular ligands, such as Tre-2/Bub2/Cdc16 domain family member 5 (TBC1D5) and VPS9-ankyrin repeat protein for VPS29 binding. Consistent with the idea of molecular mimicry in protein interactions, RidL outcompeted TBC1D5 for binding to VPS29. Furthermore, the interaction of RidL with retromer did not interfere with retromer dimerization but was essential for association of RidL with retromer-coated vacuolar and tubular endosomes. Our work thus provides structural and mechanistic evidence into how RidL is targeted to endosomal membranes.
PubMed: 29229824. Doi: 10.1073/pnas.1715361115. free PMC article
