• The Plant Pathology Journal
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• v.39 no.6
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• pp.584-591
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• 2023

Active plant immune response involving programmed cell death called the hypersensitive response (HR) is elicited by microbial effectors delivered through the type III secretion system (T3SS). The marine bacterium Hahella chejuensis contains two T3SSs that are similar to those of animal pathogens, but it was able to elicit HR-like cell death in the land plant Nicotiana benthamiana. The cell death was comparable with the transcriptional patterns of H. chejuensis T3SS-1 genes, was mediated by SGT1, a general regulator of plant resistance, and was suppressed by AvrPto1, a type III-secreted effector of a plant pathogen that inhibits HR. Thus, type III-secreted effectors of a marine bacterium are capable of inducing the nonhost HR in a land plant it has never encountered before. This suggests that plants may have evolved to cope with a potential threat posed by alien pathogen effectors. Our work documents an exceptional case of nonhost HR and provides an expanded perspective for studying plant nonhost resistance.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.2
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• pp.95-102
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• 2001

In general there are many degrees of freedom(DOFs) in industrial robots. So they have many poses of several special end-effectors positions and orientations. For that reason, industrial robots are used in a wide scope of industrial applica-tions such as welding, spray painting, deburring, and so on. In this research, an off-line continuous path planning method based on linear interpolation with parabolic blend is developed. The method safely maintains the constant orientation for base frame and end-effectors path within allowable error and minimizes the number of segments in path. This algorithm may apply to welding and painting in which the orientation is particularly significant. The simulation study of cartesian curve is carried out to show the performance of this algorithm.

• Molecules and Cells
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• v.38 no.4
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• pp.285-296
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• 2015

Oxidative stress has been linked to the pathogenesis of diabetic nephropathy, the complication of diabetes in the kidney. NADPH oxidases of the Nox family, and in particular the homologue Nox4, are a major source of reactive oxygen species in the diabetic kidney and are critical mediators of redox signaling in glomerular and tubulointerstitial cells exposed to the diabetic milieu. Here, we present an overview of the current knowledge related to the understanding of the role of Nox enzymes in the processes that control mesangial cell, podocyte and tubulointerstitial cell injury induced by hyperglycemia and other predominant factors enhanced in the diabetic milieu, including the renin-angiotensin system and transforming growth factor-${\beta}$. The nature of the upstream modulators of Nox enzymes as well as the downstream targets of the Nox NADPH oxidases implicated in the propagation of the redox processes that alter renal biology in diabetes will be highlighted.

• BMB Reports
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• v.55 no.7
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• pp.316-322
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• 2022

Ubiquitin is relatively modest in size but involves almost entire cellular signaling pathways. The primary role of ubiquitin is maintaining cellular protein homeostasis. Ubiquitination regulates the fate of target proteins using the proteasome- or autophagy-mediated degradation of ubiquitinated substrates, which can be either intracellular or foreign proteins from invading pathogens. Legionella, a gram-negative intracellular pathogen, hinders the host-ubiquitin system by translocating hundreds of effector proteins into the host cell's cytoplasm. In this review, we describe the current understanding of ubiquitin machinery from Legionella. We summarize structural and biochemical differences between the host-ubiquitin system and ubiquitin-related effectors of Legionella. Some of these effectors act much like canonical host-ubiquitin machinery, whereas others have distinctive structures and accomplish non-canonical ubiquitination via novel biochemical mechanisms.

• Proceedings of the Zoological Society Korea Conference
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• 1997.10b
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• pp.239.2-239
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• 1997

No Abstract, See Full Text

• 한국균학회소식:학술대회논문집
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• 2015.05a
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• pp.61-61
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• 2015

Rice blast, caused by the fungal pathogen Magnaporthe oryzae, is one of the most destructive diseases of rice worldwide. The rice - M. oryzae pathosystem has become a model in the study of plant - fungal interactions due to its economic importance and accumulating knowledge. During the evolutionary arms race with M. oryzae, rice plants evolved a repertoire of Resistance (R) genes to protect themselves from diseases in a gene-for-gene fashion. M. oryzae secretes a battery of small effector proteins to manipulate host functions for its successful infection, and some of them are recognized by host R proteins as avirulence effectors (AVR), which turns on strong immunity. Therefore, the analysis of interactions between AVRs and their cognate R proteins provide crucial insights into the molecular basis of plant - fungal interactions. Rice blast resistance genes Pik, Pia, Pii comprise pairs of protein-coding ORFs, Pik-1 and Pik-2, RGA4 and RGA5, Pii-1 and Pii-2, respectively. In all three cases, the paired genes are tightly linked and oriented to the opposite directions. In the AVR-Pik/Pik interaction, it has been unraveled that AVR-Pik binds to the N-terminal coiled-coil domain of Pik-1. RGA4 and RGA5 are necessary and sufficient to mediate Pia resistance and recognize the M. oryzae effectors AVR-Pia and AVR1-CO39. A domain at the C-terminus of RGA5 characterized by a heavy metal associated domain was identified as the AVR-binding domain of RGA5. Similarly, physical interactions among Pii-1, Pii-2 and AVR-Pii are being analyzed.

• The Plant Pathology Journal
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• v.34 no.1
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• pp.11-22
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• 2018

Type VI secretion system (T6SS) has been discovered in a variety of gram-negative bacteria as a versatile weapon to stimulate the killing of eukaryotic cells or prokaryotic competitors. Type VI secretion effectors (T6SEs) are well known as key virulence factors for important pathogenic bacteria. In many Burkholderia species, T6SS has evolved as the most complicated secretion pathway with distinguished types to translocate diverse T6SEs, suggesting their essential roles in this genus. Here we attempted to detect and characterize T6SSs and potential T6SEs in target genomes of plant-associated and environmental Burkholderia species based on computational analyses. In total, 66 potential functional T6SS clusters were found in 30 target Burkholderia bacterial genomes, of which 33% possess three or four clusters. The core proteins in each cluster were specified and phylogenetic trees of three components (i.e., TssC, TssD, TssL) were constructed to elucidate the relationship among the identified T6SS clusters. Next, we identified 322 potential T6SEs in the target genomes based on homology searches and explored the important domains conserved in effector candidates. In addition, using the screening approach based on the profile hidden Markov model (pHMM) of T6SEs that possess markers for type VI effectors (MIX motif) (MIX T6SEs), 57 revealed proteins that were not included in training datasets were recognized as novel MIX T6SE candidates from the Burkholderia species. This approach could be useful to identify potential T6SEs from other bacterial genomes.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.21-29
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• 1994

This paper presents a method to accommodate failures that affect aircraft dynamical characteristics, especially control surface jams on a large transport aircraft. The approach is to use the slow effectors, such as the stabilators or engines, in the feedforward manner. The simulation results indicate the performance of the RFCS. In some cases of control surface jam, the aircraft cannot recover without using the stabilators. Although the inputs to the slow effectors are determined using the nominal parameters, the effects of parameter change can be compensated by adjusting the control parameters for the fast surfaces. In the case of rudder jam, if the remaining control surfaces and the differential thrust cancel the moments produced by the stuck rudder, using the engine control improves time responses and reduces deflection angles of the control surfaces. If not, however, the aircraft starts a large rolling motion following a yawing motion. In that case, the stabilators should be used to damp the induced rolliig motion, instead of trying to directly cancel the moments caused by the stuck rudder. Unfortunately, the proposed control law for the stabilators does not give such inputs, because it does not take into account the dynamical effects which stuck surfaces have on the aircraft motions. However, we have shown through simulation that the aircraft can be recovered by giving the stabilators the control inputs that counteract the induced rolling moment. Besides, the method has also been shown through simulation to be effective in maintaining control during a situation similar to an actual accident. Finally let us mention a problem with the RFCS. As stated above, we have not established a method to select a trim point which call be reached as easily as possible using the remaining control effectors. In fact, recovery performance considerably depends on the trim states. As pointed out in Ref. 11, finding the best trim point for impaired aircraft will be one of the most difficult questions in RFCS design.

• The Plant Pathology Journal
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• v.36 no.1
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• pp.43-53
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• 2020

Ralstonia solanacearum (Rso) is a causal agent of bacterial wilt in Solanaceae crops worldwide including Republic of Korea. Rso virulence predominantly relies on type III secreted effectors (T3Es). However, only a handful of Rso T3Es have been characterized. In this study, we investigated subcellular localization of and manipulation of plant immunity by 8 Rso T3Es predicted to harbor a nuclear localization signal (NLS). While 2 of these T3Es elicited cell death in both Nicotiana benthamiana and N. tabacum, only one was dependent on suppressor of G2 allele of skp1 (SGT1), a molecular chaperone of nucleotide-binding and leucine-rich repeat immune receptors. We also identified T3Es that differentially regulate flg22-induced reactive oxygen species production and gene expression. Interestingly, several of the NLS-containing T3Es translationally fused with yellow fluorescent protein accumulated in subcellular compartments other than the cell nucleus. Our findings bring new clues to decipher Rso T3E function in planta.

• Genomics & Informatics
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• v.7 no.4
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• pp.203-207
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• 2009

The target of rapamycin (TOR) signaling pathway conserved from yeast to human plays critical roles in regulation of eukaryotic cell growth. It has been shown that TOR pathway is involved in several cellular processes, including ribosome biogenesis, nutrient response, autophagy and aging. However, due to the functional diversity of TOR pathway, we do not know yet some key effectors of the pathway. To find unknown effectors of TOR signaling pathway, we took advantage of a green fluorescent protein (GFP)-tagged collection of budding yeast Saccharomyces cerevisiae. We analyzed protein abundance changes by measuring the GFP fluorescence intensity of 4156 GFP-tagged yeast strains under inhibition of TOR pathway. Our proteomic analysis argues that 83 proteins are decreased whereas 32 proteins are increased by treatment of rapamycin, a specific inhibitor of TOR complex 1 (TORC1). We found that, among the 115 proteins that show significant changes in protein abundance under rapamycin treatment, 37 proteins also show expression changes in the mRNA levels by more than 2-fold under the same condition. We suggest that the 115 proteins indentified in this study may be directly or indirectly involved in TOR signaling and can serve as candidates for further investigation of the effectors of TOR pathway.