Putative members of the Arabidopsis Nup107‐160 nuclear pore sub‐complex contribute to pathogen defense

Abstract

SUMMARYIn eukaryotic cells, transduction of external stimuli into the nucleus to induce transcription and export of mRNAs for translation in the cytoplasm is mediated by nuclear pore complexes (NPCs) composed of nucleoporin proteins (Nups). We previously reported that Arabidopsis MOS3, encoding the homolog of vertebrate Nup96, is required for plant immunity and constitutive resistance mediated by the de-regulated Toll interleukin 1 receptor/nucleotide-binding/leucine-rich repeat (TNL)-type R gene snc1. In vertebrates, Nup96 is a component of the conserved Nup107-160 nuclear pore sub-complex, and implicated in immunity-related mRNA export. Here, we used a reverse genetics approach to examine the requirement for additional subunits of the predicted Arabidopsis Nup107-160 complex in plant immunity. We show that, among eight putative complex members, beside MOS3, only plants with defects in Nup160 or Seh1 are impaired in basal resistance. Constitutive resistance in the snc1 mutant and immunity mediated by TNL-type R genes also depend on functional Nup160 and have a partial requirement for Seh1. Conversely, resistance conferred by coiled coil-type immune receptors operates largely independently of both genes, demonstrating specific contributions to plant defense signaling. Our functional analysis further revealed that defects in nup160 and seh1 result in nuclear accumulation of poly(A) mRNA, and, in the case of nup160, considerable depletion of EDS1, a key positive regulator of basal and TNL-triggered resistance. These findings suggest that Nup160 is required for nuclear mRNA export and full expression of EDS1-conditioned resistance pathways in Arabidopsis.

HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENES1 Is Required for Circadian Periodicity through the Promotion of Nucleo-Cytoplasmic mRNA Export in Arabidopsis

“…In a proteomic screen, HOS1 interacts with the nuclear pore proteins RNA EXPORT FACTOR1-green fluorescent protein (GFP) and the nucleoporin Nup43-GFP (Tamura et al, 2010) and associates with the nuclear periphery (Lazaro et al, 2012). Nuclear pore complexes are required for the export of mRNA from the nucleus; mutating components of the nuclear pore complex results in abnormal mRNA export as shown by in situ hybridization against poly(A)-containing mRNA (Dong et al, 2006b;Parry et al, 2006;Wiermer et al, 2012). Therefore, we used in situ hybridization to detect poly(A)-containing mRNA to determine if HOS1 plays a role in nucleo-cytoplasmic mRNA export.…”

“…Circadian clock mutants used have been described and are lhy-20 (Michael et al, 2003), che-2 (Pruneda-Paz et al, 2009), prr9-10 (Ito et al, 2003), prr7-11 (Yamamoto et al, 2003), prr5-11 (Yamamoto et al, 2003), prr3-1 (Para et al, 2007), toc1-101 (Kaczorowski, 2004), gi-201 (MartinTryon et al, 2007, lux-5 (Hazen et al, 2005), elf3-1 (Hicks et al, 1996), and ztl-105 (SALK-069091) (Martin-Tryon et al, 2007). Previously published mRNA export mutants were obtained from the Nottingham Arabidopsis Stock Centre and have been previously described: sar1-4 (SALK_126801) (Parry et al, 2006), los4-1 (Gong et al, 2005), nua-3 (SAIL_505_H11) (Xu et al, 2007), nup107-1 (SALK_057072) (Wiermer et al, 2012, Clarkson et al, 1997, and hst-7 (Bollman et al, 2003).…”

LONO1Encoding a Nucleoporin Is Required for Embryogenesis and Seed Viability in Arabidopsis

“…Ten nucleoporins have been isolated and functionally characterized in plants: NUP160/ SAR1, NUP133, NUP96/SAR3/MOS3, NUP88/MOS7, NUP75/NUP85, NUP1/NUP136, RAE1, TPR/NUA, NUP107, and NUP62 (Zhang and Li, 2005;Dong et al, 2006;Kanamori et al, 2006;Parry et al, 2006;Jacob et al, 2007;Saito et al, 2007;Xu et al, 2007;Lee et al, 2009;Tamura et al, 2010;Tamura and Hara-Nishimura, 2011;Wiermer et al, 2010Wiermer et al, , 2012Zhao and Meier, 2011). These nucleoporins have been shown to regulate cell division, hormone signaling, response to stress, rhizobial and fungal symbiosis, flowering, and other aspects of plant development.…”

The molecular architecture of the plant nuclear pore complex

“…In plants, it is composed of eight nucleoporins: Nup160, Nup133, Nup107, Nup96, Nup85, Nup43, SEC13, and SEH1 (Fig. 2) (Xu and Meier, 2008;Tamura et al, 2010;Wiermer et al, 2012). Electron microscopic and biochemical analyses revealed that the yeast Nup84 subcomplex has a 40 nm long, Y-shaped, triskelion-like structure (Siniossoglou et al, 2000;Kampmann and Blobel, 2009).…”