Abstract
Rx1 is a CC-NB-LRR type resistance protein from potato that confers resistance against Potato Virus X. The Rx1 protein has a modular structure of three domains; the N-terminal coiled-coil domain (CC), the nucleotide-binding-ARC
(NB-ARC) domain and the C-terminal Leucine-rich repeat (LRR) domain. Recognition is thought to be mediated through the LRR and the signal transduction through the NB-ARC and CC domains, but the exact mechanism is still unknown. The modularity of Rx1 is such that the domains can function even if they are expressed as separate polypeptides (in trans). Until recently the NB-LRR type of R proteins were expected to be localized in the cytoplasm. The subcellular localization of Rx1 was determined by expressing fluorescently tagged Rx1 constructs. Both N- and C-terminal fusions yielded functional
R proteins. Confocal microscopy revealed that Rx1 shows a dual localization; nuclear and cytoplasmic. To investigate if any of the domains of Rx have a specific role in the subcellular distribution, a set of fluorescent fusion constructs was made of the individual domains, or combinations thereof. The
CC-domain proved to be an important factor in the nuclear localization, whereas the LRR resided mostly in the cytoplasm. Photobleaching experiments show that the CC domain binds transiently to large complexes in the nucleus. Both nuclear
accumulation and diffusion characteristics could be attributed to a stretch of 70 amino acid of the CC domain lacking classical nuclear targeting signals. Furthermore, we demonstrated that the nuclear accumulation of Rx1 depends on
ATP binding, the co-chaperones SGT-1 and RAR1, and that
(NB-ARC) domain and the C-terminal Leucine-rich repeat (LRR) domain. Recognition is thought to be mediated through the LRR and the signal transduction through the NB-ARC and CC domains, but the exact mechanism is still unknown. The modularity of Rx1 is such that the domains can function even if they are expressed as separate polypeptides (in trans). Until recently the NB-LRR type of R proteins were expected to be localized in the cytoplasm. The subcellular localization of Rx1 was determined by expressing fluorescently tagged Rx1 constructs. Both N- and C-terminal fusions yielded functional
R proteins. Confocal microscopy revealed that Rx1 shows a dual localization; nuclear and cytoplasmic. To investigate if any of the domains of Rx have a specific role in the subcellular distribution, a set of fluorescent fusion constructs was made of the individual domains, or combinations thereof. The
CC-domain proved to be an important factor in the nuclear localization, whereas the LRR resided mostly in the cytoplasm. Photobleaching experiments show that the CC domain binds transiently to large complexes in the nucleus. Both nuclear
accumulation and diffusion characteristics could be attributed to a stretch of 70 amino acid of the CC domain lacking classical nuclear targeting signals. Furthermore, we demonstrated that the nuclear accumulation of Rx1 depends on
ATP binding, the co-chaperones SGT-1 and RAR1, and that
| Original language | English |
|---|---|
| Title of host publication | ISMPMI International Congress Abstracts |
| Place of Publication | Quebec |
| Publisher | International Society for Molecular Plant-Microbe Interactions |
| Pages | 561 |
| Publication status | Published - 2009 |
| Event | XIV International Congress on Molecular Plant-Microbe Interactions - Duration: 19 Jul 2009 → 23 Jul 2009 |
Conference
| Conference | XIV International Congress on Molecular Plant-Microbe Interactions |
|---|---|
| Period | 19/07/09 → 23/07/09 |