使える単語・表現集
5. 「何が分かったか（チャチャチャチャ）」で使える単語・表現集
We found that the Agrobacterium F-box protein VirF, an important virulence factor, undergoes rapid degradation through the host proteasome pathway.
Here, we demonstrate that Agrobacterium utilizes another exported virulence protein, VirD5, to stabilize VirF, which otherwise undergoes rapid degradation through the host ubiquitin-proteasome pathway.
Using a cell-free degradation assay, we demonstrated that VirF is unstable in protein extracts prepared from N. benthamiana, one of the natural host plants of Agrobacterium.
Indeed, the cyan fluorescent protein (CFP)-tagged VirD5 protein was observed exclusively in the cell nucleus, when transiently expressed in Nicotiana benthamiana leaves
This destabilization of VirF was reduced by the proteasome inhibitors, MG132 and lactacystin, suggesting that the host ubiquitin-proteasome pathway is responsible for VirF degradation.
Consistent with this notion, we observed that VirF undergoes polyubiquitination in the plant cells.
Taken together, these observations demonstrate that VirD5 interacts with VirF.
Together, these results indicate that VirF is polyubiquitinated and targeted for the proteasome-dependent degradation in the host cells.
Surprisingly, a genome-wide mutant screen revealed that yeast strains lacking Eaf7 or Yaf9, both of which are subunits of the NuA4 complex, exhibit a strongly enhanced Agrobacterium-mediated T-DNA integration efficiency.
Furthermore, in Arabidopsis, RNAi-mediated knockdown of at least two HDACs (HDT1 and HDT2) was found to attenuate the susceptibility to Agrobacterium-mediated root transformation.
Consistent with this notion, the association of H2A.Z-containing nucleosomes with tested promoters was reduced with increasing temperature.
However, contrary to this notion, the present paper reveals specific roles of MFT, a PEBP protein, in seed germination, rather than in flowering.
It was found that listeriolysin O (LLO), a virulence factor of Listeria, indirectly promotes degradation of the E2 SUMO enzyme Ubc9, leading to a significant decrease in overall SUMOylated protein levels in human cells.
This down-regulation of the SUMO pathway seems to be favorable for the bacterial infection as SUMO over-expression, in turn, confers resistance against the pathogen in the host cells.
Detailed genetic and biochemical analyses showed that MFT controls seed germination by mediating the abscisic acid (ABA) and gibberellin (GA) signals.
Premature expression of SPL10/11 in early stages of embryogenesis and the resulting dynamic change of the downstream gene expression pattern seem to be at least partly responsible for the defective development of the dcl1 mutant embryos.
Interestingly, Arabidopsis plants lacking either PAE1 or PAE2 exhibited an increased susceptibility to Lettuce mosaic virus (LMV), indicating the critical role of the proteasome-associated RNase in antiviral defense.
The sequential reactions start with ATP-dependent activation of ubiquitin by an E1 enzyme, resulting in formation of a high energy thioester linkage between a cysteine residue present in E1 and the C-terminal glycine residue of ubiquitin.