title: Rust fungal effectors mimic host transit peptides to translocate into chloroplasts.
abstract: Parasite effector proteins target various host cell compartments to alter host processes and promote infection. How effectors cross membrane-rich interfaces to reach these compartments is a major question in effector biology. Growing evidence suggests that effectors use molecular mimicry to subvert host cell machinery for protein sorting. We recently identified chloroplast-targeted protein 1 (CTP1), a candidate effector from the poplar leaf rust fungus Melampsora larici-populina that carries a predicted transit peptide and accumulates in chloroplasts and mitochondria. Here, we show that the CTP1 transit peptide is necessary and sufficient for accumulation in the stroma of chloroplasts. CTP1 is part of a Melampsora-specific family of polymorphic secreted proteins. Two members of that family, CTP2 and CTP3, also translocate in chloroplasts in an N-terminal signal-dependent manner. CTP1, CTP2 and CTP3 are cleaved when they accumulate in chloroplasts, while they remain intact when they do not translocate into chloroplasts. Our findings reveal that fungi have evolved effector proteins that mimic plant-specific sorting signals to traffic within plant cells.
authors.affiliation: The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK.|INRA, UMR 1136 Interactions Arbres/Microorganismes, Centre INRA Nancy Lorraine, Champenoux, 54280, France.|Université de Lorraine, UMR 1136 Interactions Arbres/Microorganismes, Faculté des Sciences et Technologies, Vandoeuvre-lès-Nancy, 54506, France.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Petre
authors.affiliation: The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK.|INRA, UMR 1136 Interactions Arbres/Microorganismes, Centre INRA Nancy Lorraine, Champenoux, 54280, France.|Université de Lorraine, UMR 1136 Interactions Arbres/Microorganismes, Faculté des Sciences et Technologies, Vandoeuvre-lès-Nancy, 54506, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Lorrain
authors.affiliation: The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK.|The Genome Analysis Centre, Norwich Research Park, Norwich, NR4 7UH, UK.|The John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.
authors.forename: Diane G O
authors.initials: DG
authors.lastname: Saunders
authors.affiliation: The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK.
authors.forename: Joe
authors.initials: J
authors.lastname: Win
authors.affiliation: The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK.
authors.forename: Jan
authors.initials: J
authors.lastname: Sklenar
authors.affiliation: INRA, UMR 1136 Interactions Arbres/Microorganismes, Centre INRA Nancy Lorraine, Champenoux, 54280, France.|Université de Lorraine, UMR 1136 Interactions Arbres/Microorganismes, Faculté des Sciences et Technologies, Vandoeuvre-lès-Nancy, 54506, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Duplessis
authors.affiliation: The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK.
authors.forename: Sophien
authors.identifier: http://orcid.org/0000-0002-0290-0315
authors.initials: S
authors.lastname: Kamoun
mesh_terms: D001487:Basidiomycota / Q000502:physiology; D002736:Chloroplasts / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism*; D018716:Molecular Mimicry; D010935:Plant Diseases / Q000382:microbiology; D032107:Populus / Q000382:microbiology; D021381:Protein Transport; D037521:Virulence Factors / Q000378:metabolism*
chemical_list: D005656:Fungal Proteins; D037521:Virulence Factors