title: Lotus japonicus E3 ligase SEVEN IN ABSENTIA4 destabilizes the symbiosis receptor-like kinase SYMRK and negatively regulates rhizobial infection.
abstract: The Lotus japonicus SYMBIOSIS RECEPTOR-LIKE KINASE (SYMRK) is required for symbiotic signal transduction upon stimulation of root cells by microbial signaling molecules. Here, we identified members of the SEVEN IN ABSENTIA (SINA) E3 ubiquitin-ligase family as SYMRK interactors and confirmed their predicted ubiquitin-ligase activity. In Nicotiana benthamiana leaves, SYMRK-yellow fluorescent protein was localized at the plasma membrane, and interaction with SINAs, as determined by bimolecular fluorescence complementation, was observed in small punctae at the cytosolic interface of the plasma membrane. Moreover, fluorescence-tagged SINA4 partially colocalized with SYMRK and caused SYMRK relocalization as well as disappearance of SYMRK from the plasma membrane. Neither the localization nor the abundance of Nod-factor receptor1 was altered by the presence of SINA4. SINA4 was transcriptionally upregulated during root symbiosis, and rhizobia inoculated roots ectopically expressing SINA4 showed reduced SYMRK protein levels. In accordance with a negative regulatory role in symbiosis, infection thread development was impaired upon ectopic expression of SINA4. Our results implicate SINA4 E3 ubiquitin ligase in the turnover of SYMRK and provide a conceptual mechanism for its symbiosis-appropriate spatio-temporal containment.
authors.affiliation: Genetics, Faculty of Biology, University of Munich, 82152 Martinsried, Germany.
authors.forename: Griet
authors.initials: G
authors.lastname: Den Herder
authors.forename: Satoko
authors.initials: S
authors.lastname: Yoshida
authors.forename: Meritxell
authors.initials: M
authors.lastname: Antolín-Llovera
authors.forename: Martina K
authors.initials: MK
authors.lastname: Ried
authors.forename: Martin
authors.initials: M
authors.lastname: Parniske
mesh_terms: D018506:Gene Expression Regulation, Plant; D005799:Genes, Dominant / Q000235:genetics; D000070116:Lotus / Q000201:enzymology* / Q000235:genetics / Q000382:microbiology*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism*; D055170:Plant Root Nodulation / Q000235:genetics; D030821:Plants, Genetically Modified; D011485:Protein Binding; D011494:Protein Kinases / Q000378:metabolism*; D055550:Protein Stability; D021381:Protein Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism; D012231:Rhizobium / Q000502:physiology*; D053204:Root Nodules, Plant / Q000166:cytology / Q000235:genetics / Q000382:microbiology; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D013347:Subcellular Fractions / Q000201:enzymology; D013559:Symbiosis; D014026:Nicotiana / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism*; D000098563:Seven in Absentia Proteins
chemical_list: D009687:Nuclear Proteins; D010940:Plant Proteins; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D044767:Ubiquitin-Protein Ligases; D000098563:Seven in Absentia Proteins; D011494:Protein Kinases