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bioRxiv · 10.1101/2020.05.09.084020

Functional requirement of the Arabidopsis importin-α nuclear transport receptor family in autoimmunity mediated by the NLR protein SNC1

Lüdke, D.·Roth, C.·Kamrad, S. A.·Messerschmidt, J.·Hartken, D.·Appel, J.·Hörnich, B. F.·Yan, Q.·Kusch, S.·Klenke, M.·Gunkel, A.·Wirthmueller, L.·Wiermer, M.
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Abstract

IMPORTIN-3/MOS6 (MODIFIER OF SNC1, 6) is one of nine importin- isoforms in Arabidopsis that recruit nuclear localization signal (NLS)-containing cargo proteins to the nuclear import machinery. IMP-3/MOS6 is required genetically for full autoimmunity of the nucleotide-binding leucine-rich repeat (NLR) immune receptor mutant snc1 (suppressor of npr1-1, constitutive 1) and MOS6 also contributes to basal disease resistance. Here, we investigated the contribution of the other importin- genes to both types of immune responses, and we analyzed potential interactions of all importin- isoforms with SNC1. By using reverse-genetic analyses in Arabidopsis and protein-protein interaction assays in N. benthamiana we provide evidence that among the nine -importins in Arabidopsis, IMP-3/MOS6 is the main nuclear transport receptor of SNC1, and that IMP-3/MOS6 is required selectively for autoimmunity of snc1 and basal resistance to mildly virulent Pseudomonas syringae in Arabidopsis. SIGNIFICANCE STATEMENTSpecific requirement for the Arabidopsis -importin MOS6 in snc1-mediated autoimmunity is explained by selective formation of MOS6-SNC1 nuclear import complexes.

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Lüdke, D., Roth, C., Kamrad, S. A., Messerschmidt, J., Hartken, D., Appel, J., Hörnich, B. F., Yan, Q., Kusch, S., Klenke, M., Gunkel, A., Wirthmueller, L., Wiermer, M.. 2020-05-10. Functional requirement of the Arabidopsis importin-α nuclear transport receptor family in autoimmunity mediated by the NLR protein SNC1. https://doi.org/10.1101/2020.05.09.084020

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