A structure-aided approach to understand downy mildew effectors and their targets

LENNART WIRTHMUELLER; SHUTA ASAI; MARIE-CECILE CAILLAUD; GANASHYAM RALLAPALLI; GEORGINA FABRO; WRZACZEK M; KANGASJARVI J; JAN SKLENAR; FRANK MENKE; MARK BANFIELD; JONATHAN D. G. JONES

Zakopane

Congreso; COST 2nd-Annual-Conference; 2014

European Cooperation in Science and Technology- COST-

Protein-protein interaction screens continue to identify host proteins that bind to effectors from filamentous plant pathogens. However, the molecular consequences of many effector/target interactions remain unknown and not all plant proteins that bind to effectors are virulence targets. Therefore the next critical step is to understand the molecular functions of select effectors and how they manipulate host proteins. We use a combination of in planta virulence assays, x-ray crystallography and protein biochemistry to elucidate structures, molecular functions and host targets of effectors from the Arabidopsis downy mildew pathogen Hyaloperonospora arabidopsidis (Hpa). We prioritize Hpa effectors that localize to the host cell nucleus and suppress defence gene expression. Several nuclear Hpa effectors interact with core components of the transcriptional machinery, suggesting that they directly manipulate defence gene transcription. I will present our on-going work aiming to understand how Hpa effectors perturb transcription of host defence genes at the molecular level.