• Parasites, Hosts and Diseases
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• v.53 no.1
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• pp.65-75
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• 2015

Clonorchis sinensis habitating in the bile duct of mammals causes clonorchiasis endemic in East Asian countries. Parkin is a RING-between-RING protein and has E3-ubiquitin ligase activity catalyzing ubiquitination and degradation of substrate proteins. A cDNA clone of C. sinensis was predicted to encode a polypeptide homologous to parkin (CsParkin) including 5 domains (Ubl, RING0, RING1, IBR, and RING2). The cysteine and histidine residues binding to $Zn^{2+}$ were all conserved and participated in formation of tertiary structural RINGs. Conserved residues were also an E2-binding site in RING1 domain and a catalytic cysteine residue in the RING2 domain. Native CsParkin was determined to have an estimated molecular weight of 45.7 kDa from C. sinensis adults by immunoblotting. CsParkin revealed E3-ubiquitin ligase activity and higher expression in metacercariae than in adults. CsParkin was localized in the locomotive and male reproductive organs of C. sinensis adults, and extensively in metacercariae. Parkin has been found to participate in regulating mitochondrial function and energy metabolism in mammalian cells. From these results, it is suggested that CsParkin play roles in energy metabolism of the locomotive organs, and possibly in protein metabolism of the reproductive organs of C. sinensis.

• Proceedings of the Korean Society of Crop Science Conference
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• 2023.04a
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• pp.156-156
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• 2023

Salinity is a major abiotic stress that limits rice productivity in many regions of the world. In order to develop salt stress tolerant rice plants, genetic engineering is a promising approach. We characterized the molecular function of rice C3H2C3 as a really interesting new gene (RING). Oryza sativa RING finger protein H2-3 (OsRFPH2-3) was highly expressed in 100 mM NaCl. To identify the localization of OsRFPH2-3, we fused vectors that include C-terminal GFP protein (35S;;OsRFPH2-3-GFP). OsRFPH2-3 was expressed in the nucleus in rice protoplasts. An in vitro ubiquitin assay demonstrated that OsRFPH2-3 possessed E3-ubiquitin ligase activity. However, the mutated OsRFPH2-3 were not possessed any E3-ubiquitin ligase activity. Under salinity conditions, OsRFPH2-3-overexpressing plants exhibited higher chlorophyll, proline, SOD, POD, CAT, and soluble sugar contents and lower H₂O₂ accumulation than wild-type plants, supporting transgenic plants with enhanced salinity tolerance phenotypes. OsRFPH2-3-overexpressing plants exhibited low Na+ accumulation and Na+/K+ ratios in their roots. Theses results suggest that overexpression of OsRFPH2-3 can make plant insensitivity about salinity conditions.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.189-189
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• 2022

Soil salinity negatively affects plant growth, productivity, and metabolism. Rice is known to have more sensitive phenotypes than other cereal crops, such as wheat, sorghum, and barley. We characterized the molecular function of rice C3HC4 as a really interesting new gene (RING). Oryza sativa RING finger protein H2-3 (OsRFPH2-3) was highly expressed in 100 mM NaCl. To identify the localization of OsRFPH2-3, we fused vectors that include C-terminal GFP protein (35S;;OsRFPH2-3-GFP). OsRFPH2-3 was expressed in the nucleus in rice protoplasts. An in vitro ubiquitin assay demonstrated that OsRFPH2-3 possessed E3-ubiquitin ligase activity. However, the mutated OsRFPH2-3 were not possessed any E3-ubiquitin ligase activity. Under normal conditions, there is no significant phenotypic difference between transgenic plants and WT plants. However, OsRFPH2-3-overexpressing plants exhibited higher fresh weight and length under saline conditions. Also, transgenic plants maintain higher chlorophyll, proline, and soluble sugar contents and lower H₂O₂ and MDA contents than the wild type; these results support transgenic plants with enhanced salinity tolerance phenotypes.

• Molecules and Cells
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• v.43 no.11
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• pp.935-944
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• 2020

Aryl hydrocarbon receptor nuclear translocator (ARNT) plays an essential role in maintaining cellular homeostasis in response to environmental stress. Under conditions of hypoxia or xenobiotic exposure, ARNT regulates the subset of genes involved in adaptive responses, by forming heterodimers with hypoxia-inducible transcription factors (HIF1α and HIF2α) or aryl hydrocarbon receptor (AhR). Here, we have shown that ARNT interacts with DDB1 and CUL4-associated factor 15 (DCAF15), and the aryl sulfonamides, indisulam and E7820, induce its proteasomal degradation through Cullin-RING finger ligase 4 containing DCAF15 (CRL4^DCAF15) E3 ligase. Moreover, the two known neo-substrates of aryl sulfonamide, RNA-binding motif protein 39 (RBM39) and RNA-binding motif protein 23 (RBM23), are not required for ARNT degradation. In line with this finding, aryl sulfonamides inhibited the transcriptional activities of HIFs and AhR associated with ARNT. Our results collectively support novel regulatory roles of aryl sulfonamides in both hypoxic and xenobiotic responses.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.149-149
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• 2017

The RING (Really Interesting New Gene) finger proteins are known to play crucial roles in various abiotic stresses in plants. In this study, we report on RING finger E3 ligase, ${\underline{O}ryza}$ ${\underline{s}ativa}$ ${\underline{s}alt$-, ${\underline{A}BA}$- and ${\underline{d}rounght}$ stress-${\underline{i}nduced}$ RING finger ${\underline{p}}rotein{\underline{1}}$ gene (OsSAD1). In vitro ubiquitination assay demonstrated that unlike OsSAD1, a single amino acid substitution ($OsSAD1^{C168A}$) of the RING domain showed no E3 ligase activity, supporting the notion that the activity of most E3s is specified by a RING domain. Result of Yeast-Two hybridization, In vivo protein degradation assay supports that OsSAD1 interacting with 3 substrate, OsSNAC2, OsGRAS44 and OsPIRIN1, and mediates proteolysis of 3 substrates via the 26S proteasome pathway. Subcellular localizations of OsSAD1 while approximately 62% of transient signals were detected in cytosol, 38% of signals were showed nucleus. However, transiently expression of OsSAD1 was detected in cytosol 30% while as 70% of nucleus under 200 mM salt treated rice protoplasts. Results of bimolecular fluorescence complementation (BiFC) showed that two nucleus-localized proteins (OsSNAC2 and OsGRAS44) interacted with OsSAD1 in the both cytosol and nucleus. Heterogeneous overexpression of OsSAD1 Heterogeneous overexpresssion of OsSAD1 in Arabidopsis exhibited sensitive phenotypes with respect to Salt-, mannitol-responsive seed germination, seedling growth. In ABA conditions, OsSAD1 overexpression plants showed highly tolerance phenotypes, such as root length and stomatal closure. Our findings suggest that the OsSAD1 may play a negative regulator in salt stress response by modulating levels of its target proteins.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.150-150
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• 2017

Plants suffer from various abiotic stresses among them; soil salinity is one of major adverse factor in declining agricultural productivity. So, development of salt stress tolerance crops have potential role to increase crop production. The RING finger proteins are known to play crucial roles in abiotic stress environment to plants. In this study, we identified one Salt-responsive Really${\underline{I}nteresting}$ ${\underline{n}ew}$ ${\underline{g}ene}$ (RING) E3 ubiquitin ligase gene OsSIRF1 from rice root tissues during salt stress and studied its molecular function. Expression of OsSIRF1 was induced under various abiotic stress conditions, including salt, heat, drought, and ABA. Result of an in vitro ubiquitination assay clearly showed that OsSIRF1 Possess an E3 ligase activity. Moreover, OsSIRF1 was found to be localized to the nucleus within the cell. Heterogeneous overexpression of OsSIRF1 in Arabidopsis improved seed germination and increased root length under salt and Manitol stress conditions. Taking together, these results suggested that OsSIRF1 may be associated with plant responses to abiotic stressors and positively regulates salt and osmotic stress environment.

• Proceedings of the Korean Society of Crop Science Conference
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• 2020.06a
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• pp.165-165
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• 2020

• BMB Reports
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• v.50 no.8
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• pp.393-400
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• 2017

Plants are constantly exposed to a variety of abiotic stresses, such as drought, heat, cold, flood, and salinity. To survive under such unfavorable conditions, plants have evolutionarily developed their own resistant-mechanisms. For several decades, many studies have clarified specific stress response pathways of plants through various molecular and genetic studies. In particular, it was recently discovered that ubiquitin proteasome system (UPS), a regulatory mechanism for protein turn over, is greatly involved in the stress responsive pathways. In the UPS, many E3 ligases play key roles in recognizing and tethering poly-ubiquitins on target proteins for subsequent degradation by the 26S proteasome. Here we discuss the roles of RING ligases that have been defined in related to abiotic stress responses in plants.

• Proceedings of the Zoological Society Korea Conference
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• 2001.10a
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• pp.252.1-252
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• 2001

No Abstract, See Full Text

• Animal cells and systems
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• v.9 no.4
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• pp.181-190
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• 2005

BIRPs (BIR containing Proteins) which contain one to three BIR domains constitute a highly conserved family from yeast to human. BIR domains mediate the interaction of BIRPs with various other proteins. Some of the members acquire a Ring domain which acts as an E3 ubiquitin ligase. The first member of BIRPs identified in the baculovirus was found as an inhibitor of apoptosis and most of the family members in the other species have been recognized to have the same function which bind to and inhibit caspases, thereby suppresses apoptotic cell death. But an increasing number of evidences indicate that BIRPs are involved in various cellular events such as cell division, control of cell cycle, signal transduction, cell migration, innate immunity as well as regulation of apoptosis. In this review, we summarize the structural and functional features of the BIRPs, especially focus on the various functions of BIRPs unrelated to regulation of apoptosis by the recent findings.