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Dongwon Baek,
Min Chul Kim,
Hyun Jin Chun,
Songhwa Kang,
Hyeong Cheol Park,
Gilok Shin,
Jiyoung Park,
Mingzhe Shen,
Hyewon Hong,
Woe-Yeon Kim, Doh Hoon Kim,
Ray A Bressan,
Hans J Bohnert,
Dae-Jin Yun
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ABSTRACT: Although a role for microRNA399 (miR399) in plant responses to phosphate (Pi) starvation has been indicated, the regulatory mechanism underlying miR399 gene expression is not clear. Here we report that AtMYB2 functions as a direct transcriptional activator for miR399 in Arabidopsis Pi starvation signaling. Compared to untransformed control plants, transgenic plants constitutively overexpressing AtMYB2 showed increased miR399f expression and tissue Pi contents under high Pi growth, and exhibited elevated expression of a subset of Pi starvation-induced (PSI) genes. Pi-starvation-induced root architectural changes were more exaggerated in AtMYB2 overexpressing transgenic plants compared to wild type. AtMYB2 directly binds to a MYB-binding site in the miR399f promoter in vitro, as well as in vivo, and stimulates miR399f promoter activity in Arabidopsis protoplasts. Transcription of AtMYB2 itself is induced in response to Pi deficiency, and the tissue expression pattern of miR399f and AtMYB2 are similar. Both genes are expressed mainly in vascular tissues of cotyledons and in roots. Our results suggest that AtMYB2 regulates plant responses to Pi-starvation by regulating the expression of the miR399 gene.
Plant physiology 11/2012; · 6.53 Impact Factor
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Nan Jiang,
Eun-Hee Jeon,
Jung-Hun Pak,
Tae-Joung Ha,
In-Youl Baek,
Woo-Suk Jung,
Jai-Heon Lee, Doh-Hoon Kim,
Hong-Kyu Choi,
Zheng Cui,
Young-Soo Chung
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ABSTRACT: Plant secondary metabolites have always been a focus of study due to their important roles in human medicine and nutrition.
We transferred the isoflavone synthase (IFS) gene into soybean [Glycine max (L.) Merr.] using the Agrobacterium-mediated transformation method in an attempt to produce transformed soybean plants which produced increased levels of the
secondary metabolite, isoflavone. Although the trial to produce transgenic plant failed due to unestablished hygromycin selection,
transformed callus cell lines were obtained. The induction rate and degree of callus were similar among the three cultivars
tested, but light illumination positively influenced the frequency of callus formation, resulting in a callus induction rate
of 74% for Kwangan, 67% for Sojin, and 73% for Duyou. Following seven to eight subcultures on selection media, the isoflavone
content of the transformed callus lines were analyzed by high-performance liquid chromatography. The total amount of isoflavone
in the transformed callus cell lines was three- to sixfold higher than that in control callus or seeds. Given the many positive
effects of isoflavone on human health, it may be possible to adapt our transformed callus lines for industrialization through
an alternative cell culture system to produce high concentrations of isoflavones.
KeywordsSoybean callus-Isoflavonoids-
Agrobacterium-mediated transformation-HPLC
Plant Biotechnology Reports 04/2012; 4(4):253-260. · 1.19 Impact Factor
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Mi-Jin Kim,
Jae Kwang Kim,
Hye Jeong Kim,
Jung Hun Pak,
Jai-Heon Lee, Doh-Hoon Kim,
Hong Kyu Choi,
Ho Won Jung,
Jeong-Dong Lee,
Young-Soo Chung,
Sun-Hwa Ha
[show abstract]
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ABSTRACT: The carotenoid biosynthetic pathway was genetically manipulated using the recombinant PAC (Phytoene synthase-2A-Carotene desaturase) gene in Korean soybean (Glycine max L. cv. Kwangan). The PAC gene was linked to either the β-conglycinin (β) or CaMV-35S (35S) promoter to generate β-PAC and 35S-PAC constructs, respectively. A total of 37 transgenic lines (19 for β-PAC and 18 for 35S-PAC) were obtained through Agrobacterium-mediated transformation using the modified half-seed method. The multi-copy insertion of the transgene was determined by genomic Southern blot analysis. Four lines for β-PAC were selected by visual inspection to confirm an orange endosperm, which was not found in the seeds of the 35S-PAC lines. The strong expression of PAC gene was detected in the seeds of the β-PAC lines and in the leaves of the 35S-PAC lines by RT-PCR and qRT-PCR analyses, suggesting that these two different promoters function distinctively. HPLC analysis of the seeds and leaves of the T(2) generation plants revealed that the best line among the β-PAC transgenic seeds accumulated 146 µg/g of total carotenoids (approximately 62-fold higher than non-transgenic seeds), of which 112 µg/g (77%) was β-carotene. In contrast, the level and composition of the leaf carotenoids showed little difference between transgenic and non-transgenic soybean plants. We have therefore demonstrated the production of a high β-carotene soybean through the seed-specific overexpression of two carotenoid biosynthetic genes, Capsicum phytoene synthase and Pantoea carotene desaturase. This nutritional enhancement of soybean seeds through the elevation of the provitamin A content to produce biofortified food may have practical health benefits in the future in both humans and livestock.
PLoS ONE 01/2012; 7(10):e48287. · 4.09 Impact Factor
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ABSTRACT: The ubiquitin-26S proteasome system is important in the quality control of intracellular proteins. The ubiquitin-26S proteasome system includes the E1 (ubiquitin activating), E2 (ubiquitin conjugating), and E3 (ubiquitin ligase) enzymes. U-box proteins are a derived version of RING-finger domains, which have E3 enzyme activity. Here, we present the isolation of a novel U-box protein, U-box containing E3 ligase induced by phosphate starvation (OsUPS), from rice (Oryza sativa). The cDNA encoding the O. sativa U-box protein (OsUPS) comprises 1338 bp, with an open reading frame of 445 amino acids. The amino acid sequence of OsUPS cDNA shows 41-79% identity with other plant U-box homologous genes. The open reading frame of the OsUPS protein is comprised of notable domains: a single ~70-amino acid domain and a GKL domain that contains conserved glycine, lysine/arginine residues and leucine-rich feature. We found that full-length expression of OsUPS was up-regulated in both rice plants and cell culture in the absence of inorganic phosphate (P(i)). A self-ubiquitination assay indicated that the bacterially expressed OsUPS protein had E3 ligase activity, and subcellular localization results showed that OsUPS was located in the chloroplast. These results support the notion that OsUPS plays an important role in the P(i) signaling pathway through the ubiquitin-26S proteasome system.
Molecular Biology Reports 12/2011; 39(5):5883-8. · 2.93 Impact Factor
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ABSTRACT: Bee venom is a rich source of pharmacologically active components; it has been used as an immunotherapy to treat bee venom hypersensitivity, and venom therapy has been applied as an alternative medicine. Here, we present evidence that the serine protease found in bumblebee venom exhibits fibrin(ogen)olytic activity. Compared to honeybee venom, bumblebee venom contains a higher content of serine protease, which is one of its major components. Venom serine proteases from bumblebees did not cross-react with antibodies against the honeybee venom serine protease. We provide functional evidence indicating that bumblebee (Bombus terrestris) venom serine protease (Bt-VSP) acts as a fibrin(ogen)olytic enzyme. Bt-VSP activates prothrombin and directly degrades fibrinogen into fibrin degradation products. However, Bt-VSP is not a plasminogen activator, and its fibrinolytic activity is less than that of plasmin. Taken together, our results define roles for Bt-VSP as a prothrombin activator, a thrombin-like protease, and a plasmin-like protease. These findings offer significant insight into the allergic reaction sequence that is initiated by bee venom serine protease and its potential usefulness as a clinical agent in the field of hemostasis and thrombosis.
Toxicology and Applied Pharmacology 09/2011; 255(2):207-13. · 4.45 Impact Factor
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ABSTRACT: 2-Aminoindan-2-phosphonic acid (AIP), a specific competitive phenylalanine ammonia lyase (PAL) inhibitor was applied to a suspension cell culture of Cistanche deserticola. The effects of AIP treatment on cell growth, PAL activity, contents and yields of total phenolic compound, salidroside and four phenylethanoid glycosides (PheGs) are investigated. The results demonstrated that, 0.5 and 2.0 μM AIP treatments had similar effects on the measurements investigated in this study. AIP treatment resulted in significant decreases in PAL activity, total phenolic compounds content, and PheGs content. Linear regression analysis showed that PAL activity had a high correlation coefficient with the total phenolic compound content and the four PheGs contents. Total PAL activity-time area under curve (AUC) had a high correlation coefficient with the total phenolic compound yield and the yields of five tested compounds in untreated cell samples. In AIP-treated cells, total PAL activity-time AUC retained a high correlation with the total phenolic compound yield and the yields of three tested compounds, echinacoside, acteoside, and tubuloside A, but not salidroside and cistanoside A. The difference could be caused by the different biosynthetic origins of each of the tested compounds. These results demonstrate the important role of PAL in the biosynthesis of PheGs in the suspension cell culture of C. deserticola.
Plant Cell Reports 01/2011; 30(4):665-74. · 2.27 Impact Factor
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ABSTRACT: We cloned the gene, CdPAL1, from Cistanche deserticola callus using RACE PCR with degenerate primers that were designed based on a multiple sequence alignment of known PAL genes from other plant species. The gene shows high homology to other known PAL genes registered in GenBank. The recombinant protein exhibited Michaelis-Menten kinetics with a Km of 0.1013 mM, Vmax of 4.858 μmol min(-1), Kcat of 3.36 S(-1), and Kcat/Km is 33,168 M(-1) S(-1). The enzyme had an optimal pH of 8.5 and an activation energy of 38.92 kJ mol(-1) when L-Phenylalanine was used as a substrate; L-tyrosine cannot be used as substrate for this protein. The optimal temperature was 55°C, and the thermal stability results showed that, after a treatment at 70°C for 20 min, the protein retained 87% activity, while a treatment at 75°C for 20 min resulted in a loss of over 85% of the enzyme activity. Treatment with heavy metal ions (Hg2+, Pb2+, and Zn2+) showed remarkable inhibitory effects. Among the intermediates from the lignin (cinnamyl alcohol, cinnamyl aldehyde, coniferyl aldehyde, coniferyl alcohol), phenylpropanoid (cinnamic acid, coumaric acid, caffeic acid, and chlorogenic acid) and phenylethanoid (tyrosol and salidroside) biosynthetic pathways, only cinnamic acid showed strong inhibitory effects against CdPAL1 activity with a Ki of 8 μM. Competitive inhibitor AIP exhibited potent inhibition with Ki=0.056 μM.
Molecular Biology Reports 11/2010; 38(6):3741-50. · 2.93 Impact Factor
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Hyeong Cheol Park,
Hun Kim,
Sung Cheol Koo,
Hee Jin Park,
Mi Sun Cheong,
Hyewon Hong,
Dongwon Baek,
Woo Sik Chung, Doh Hoon Kim,
Ray A Bressan,
Sang Yeol Lee,
Hans J Bohnert,
Dae-Jin Yun
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ABSTRACT: Sumoylation is a post-translational regulatory process in diverse cellular processes in eukaryotes, involving conjugation/deconjugation of small ubiquitin-like modifier (SUMO) proteins to other proteins thus modifying their function. The PIAS [protein inhibitor of activated signal transducers and activators of transcription (STAT)] and SAP (scaffold attachment factor A/B/acinus/PIAS)/MIZ (SIZ) proteins exhibit SUMO E3-ligase activity that facilitates the conjugation of SUMO proteins to target substrates. Here, we report the isolation and molecular characterization of Oryza sativa SIZ1 (OsSIZ1) and SIZ2 (OsSIZ2), rice homologs of Arabidopsis SIZ1. The rice SIZ proteins are localized to the nucleus and showed sumoylation activities in a tobacco system. Our analysis showed increased amounts of SUMO conjugates associated with environmental stresses such as high and low temperature, NaCl and abscisic acid (ABA) in rice plants. The expression of OsSIZ1 and OsSIZ2 in siz1-2 Arabidopsis plants partially complemented the morphological mutant phenotype and enhanced levels of SUMO conjugates under heat shock conditions. In addition, ABA-hypersensitivity of siz1-2 seed germination was partially suppressed by OsSIZ1 and OsSIZ2. The results suggest that rice SIZ1 and SIZ2 are able to functionally complement Arabidopsis SIZ1 in the SUMO conjugation pathway. Their effects on the Arabidopsis mutant suggest a function for these genes related to stress responses and stress adaptation.
Plant Cell and Environment 11/2010; 33(11):1923-34. · 5.22 Impact Factor
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ABSTRACT: A full-length cDNA clone with high homology (62% mature peptide sequence identity) to an Acalolepta luxuriosa antibacterial gene, possessing a conserved cysteine-stabilized αβ motif, was cloned by screening an Apriona germari cDNA library. This gene (AgCRP) had a total length of 360 bp with an open reading frame of 207 bp, and encoded a predicted peptide of 69 amino acid residues. The mature AgCRP peptide was 27 amino acid residues long and had a cysteine-stabilized αβ motif of C…CXXXC…C…CXC consensus sequence, similar to insect defensins. Northern blot analysis revealed that the AgCRP exhibited fat body-specific expression and was up-regulated by wounding, bacterial or fungal challenge.
07/2009; 18(2):160-164.
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ABSTRACT: Voltage-dependent anion channels (VDACs) are reported to be porin-type, beta-barrel diffusion pores. They are prominently localized in the outer mitochondrial membrane and are involved in metabolite exchange between the organelle and the cytosol. In this study, we have investigated a family of VDAC isoforms in Arabidopsis thaliana (AtVDAC). We have shown that the heterologous expression of AtVDAC proteins can functionally complement a yeast mutant lacking the endogenous mitochondrial VDAC gene. AtVDACs tagged with GFP were localized to mitochondria in both yeast and plant cells. We also looked at the response of AtVDACs to biotic and abiotic stresses and found that four AtVDAC transcripts were rapidly up-regulated in response to a bacterial pathogen.
Molecules and Cells 04/2009; 27(3):321-7. · 2.18 Impact Factor
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ABSTRACT: Calmodulin-regulated protein phosphorylation plays a pivotal role in amplifying and diversifying the action of calcium ion. In this study, we identified a calmodulin-binding receptor-like protein kinase (CBRLK1) that was classified into an S-locus RLK family. The plasma membrane localization was determined by the localization of CBRLK1 tagged with a green fluorescence protein. Calmodulin bound specifically to a Ca(2+)-dependent calmodulin binding domain in the C-terminus of CBRLK1. The bacterially expressed CBRLK1 kinase domain could autophosphorylate and phosphorylates general kinase substrates, such as myelin basic proteins. The autophosphorylation sites of CBRLK1 were identified by mass spectrometric analysis of phosphopeptides.
FEBS letters 01/2009; 583(1):36-42. · 3.54 Impact Factor
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ABSTRACT: Transferrin and ferritin are iron-binding proteins involved in transport and storage of iron as part of iron metabolism. Here, we describe the cDNA cloning and characterization of transferrin (Bi-Tf) and the ferritin heavy chain subunit (Bi-FerHCH), from the bumblebee Bombus ignitus. Bi-Tf cDNA spans 2340 bp and encodes a protein of 706 amino acids and Bi-FerHCH cDNA spans 1393 bp and encodes a protein of 217 amino acids. Comparative analysis revealed that Bi-Tf appears to have residues comprising iron-binding sites in the N-terminal lobe, and Bi-FerHCH contains a 5'UTR iron-responsive element and seven conserved amino acid residues associated with a ferroxidase center. The Bi-Tf and Bi-FerHCH cDNAs were expressed as 79 kDa and 27 kDa polypeptides, respectively, in baculovirus-infected insect Sf9 cells. Northern blot analysis revealed that Bi-Tf exhibits fat body-specific expression and Bi-FerHCH shows ubiquitous expression. The expression profiles of the Bi-Tf and Bi-FerHCH in the fat body of B. ignitus worker bees revealed that Bi-Tf and Bi-FerHCH are differentially induced in a time-dependent manner in a single insect by wounding, bacterial challenge, and iron overload.
Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology 10/2008; 152(1):20-7. · 1.61 Impact Factor
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Eun Hee Jeon,
Eun Sook Chung,
Jung Hun Pak,
Jae Sung Nam,
Sung Ki Cho,
Sang Hyun Shin, Doh Hoon Kim,
Gyung Tae Kim,
Jai Heon Lee,
Kyung Ho Kang,
Young Soo Chung
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ABSTRACT: A full-length cDNA of the OgPAE1 gene encoding the alpha5 subunit of the 20S proteasome was isolated from wild rice (Oryza grandiglumis) treated by wounding or with a fungal elicitor. The deduced amino acid sequence of OgPAE1 comprises 237 amino acids (25.99 kDa), and shows 94.5% homology with Arabidopsis thaliana AtPAE1. Expression of OgPAE1 is regulated by defense-related signaling chemicals such as cantharidin, endothall and jasmonic acid. Overexpression of OgPAE1 in A. thaliana leads to resistance to the fungal pathogen Botrytis cinerea by lowering disease rate and size of necrotic lesions, and by less penetration and colonization of fungal hyphae. The results indicate that the 20S proteasome from wild rice is involved in the B. cinerea defense pathway via an as yet undetermined mechanism.
Journal of Plant Research 08/2008; 121(4):435-40. · 1.75 Impact Factor
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Hyoun-Mi Seo,
Yunhui Jung,
Songyi Song,
Yunhye Kim,
Tackmin Kwon, Doh-Hoon Kim,
Soon-Jae Jeung,
Young-Byung Yi,
Gihwan Yi,
Min-Hee Nam,
Jaesung Nam
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ABSTRACT: Most high-affinity phosphate transporter genes (OsPTs) in rice were highly induced in roots when phosphate was depleted. OsPT1, however, was highly expressed in primary roots and leaves regardless of external phosphate concentrations. This finding was confirmed histochemically using transgenic rice plants that express the GUS reporter gene under the control of the OsPT1 promoter, which exhibited high GUS activity even in the phosphate sufficient condition. Furthermore, transgenic rice plants overexpressing the OsPT1 gene accumulated almost twice as much phosphate in the shoots as did wild-type plants. As a result, transgenic plants had more tillers than did wild-type plants, which is a typical physiological indicator for phosphate status in rice.
Biotechnology Letters 07/2008; 30(10):1833-8. · 1.68 Impact Factor
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Dongwon Baek,
Yinhua Jin,
Jae Cheol Jeong,
Hyo-Jung Lee,
Haejeong Moon,
Jiyoung Lee,
Dongjin Shin,
Chang Ho Kang, Doh Hoon Kim,
Jaesung Nam,
Sang Yeol Lee,
Dae-Jin Yun
[show abstract]
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ABSTRACT: Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a classical glycolytic enzyme, is involved in cellular energy production and has important housekeeping functions. In this report, we show that a GAPDH from Arabidopsis, GAPDHa, has a novel function involved in H(2)O(2)-mediated cell death in yeast and Arabidopsis protoplasts. GAPDHa was cloned along with other plant genes that suppress Bax-induced cell death in yeast. Flow cytometry analyses with dihydrorhodamine 123 indicated that H(2)O(2) production mediated by Bax expression in yeast cells was greatly reduced when Bax was coexpressed with GAPDHa. In plants, GAPDHa transcript levels were greatly increased by H(2)O(2) treatment. Furthermore, transformation of GAPDHa into Arabidopsis protoplasts strongly suppressed heat shock-induced H(2)O(2) production and cell death. Together, our results indicate that GAPDH controls generation of H(2)O(2) by Bax and heat shock, which in turn suppresses cell death in yeast and plant cells.
Phytochemistry 02/2008; 69(2):333-8. · 3.35 Impact Factor
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Chang-Woo Cho,
Hye-Jeong Lee,
Eunsook Chung,
Kyoung Mi Kim,
Jee Eun Heo,
Jung-In Kim,
Jongil Chung,
Youzhi Ma,
Kiichi Fukui,
Dae-Won Lee, Doh-Hoon Kim,
Young-Soo Chung,
Jai-Heon Lee
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ABSTRACT: L-asparaginase (EC 3.5.1.1) catalyzes the hydrolysis of the amide group of L-asparagine, releasing aspartate and NH4+. We isolated a low temperature-inducible cDNA sequence encoding L-asparaginase from soybean leaves. The full-length L-asparaginase cDNA, designated GmASP1, contains an open reading frame of 1,258 bp coding for a protein of 326 amino acids. Genomic DNA blotting and fluorescence in situ hybridization showed that the soybean genome has two copies of GmASP1. GmASP1 mRNA was induced by low temperature, ABA and NaCl, but not by heat shock or drought stress. E. coli cells expressing recombinant GmASP1 had 3-fold increased L-asparaginase activity. A possible function of L-asparaginase in the early response to low temperature stress is discussed.
Molecules and Cells 07/2007; 23(3):280-6. · 2.18 Impact Factor
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ABSTRACT: A phosphate starvation-induced acid phosphatase cDNA was cloned from the rice, Oryza sativa. The cDNA encoding O. sativa acid phosphatase (OsACP1) has 1100 bp with an open reading frame of 274 amino acid residues. The deduced amino acid sequence of OsACP1 cDNA showed 53% identity to tomato acid phosphatase and 46-50% identity to several other plant phosphatases. OsACP1 expression was up-regulated in the rice plant and in cell culture in the absence of phosphate (Pi). The induced expression of OsACP1 was a specific response to Pi starvation, and was not affected by the deprivation of other nutrients. OsACP1 expression was responsive to the level of Pi supply, with transcripts of OsACP1 being abundant in Pi-deprived root. The OsACP1 cDNA was expressed as a 30 kDa polypeptide in baculovirus-infected insect Sf9 cells. In addition, the OsACP1 gene was introduced into Arabidopsis via Agrobacterium-mediated transformation. Functional expression of the OsACP1 gene in the transgenic Arabidopsis lines was confirmed by Northern blot and Western blot analyses, as well as phosphatase activity assays. These results suggest that the OsACP1 gene can be used to develop new transgenic dicotyledonous plants able to adapt to Pi-deficient conditions.
Biotechnology Letters 06/2007; 29(5):829-35. · 1.68 Impact Factor
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ABSTRACT: A full-length cDNA clone with high homology (62% mature peptide sequence identity) to an Acalolepta luxuriosa antibacterial gene, possessing a conserved cysteine-stabilized alphabeta motif, was cloned by screening an Apriona germari cDNA library. This gene (AgCRP) had a total length of 360 bp with an open reading frame of 207 bp, and encoded a predicted peptide of 69 amino acid residues. The mature AgCRP peptide was 27 amino acid residues long and had a cysteine-stabilized alphabeta motif of C...CXXXC...C...CXC consensus sequence, similar to insect defensins. Northern blot analysis revealed that the AgCRP exhibited fat body-specific expression and was up-regulated by wounding, bacterial or fungal challenge.
DNA Sequence 05/2007; 18(2):160-4. · 0.75 Impact Factor
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Jiyoung Lee,
Jaesung Nam,
Hyeong Cheol Park,
Gunnam Na,
Kenji Miura,
Jing Bo Jin,
Chan Yul Yoo,
Dongwon Baek, Doh Hoon Kim,
Jae Cheol Jeong, [......],
Sang Yeol Lee,
David E Salt,
Tesfaye Mengiste,
Qingqiu Gong,
Shisong Ma,
Hans J Bohnert,
Sang-Soo Kwak,
Ray A Bressan,
Paul M Hasegawa,
Dae-Jin Yun
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ABSTRACT: Reversible modifications of target proteins by small ubiquitin-like modifier (SUMO) proteins are involved in many cellular processes in yeast and animals. Yet little is known about the function of sumoylation in plants. Here, we show that the SIZ1 gene, which encodes an Arabidopsis SUMO E3 ligase, regulates innate immunity. Mutant siz1 plants exhibit constitutive systemic-acquired resistance (SAR) characterized by elevated accumulation of salicylic acid (SA), increased expression of pathogenesis-related (PR) genes, and increased resistance to the bacterial pathogen Pseudomonas syringae pv. tomato (Pst) DC3000. Transfer of the NahG gene to siz1 plants results in reversal of these phenotypes back to wild-type. Analyses of the double mutants, npr1 siz1, pad4 siz1 and ndr1 siz1 revealed that SIZ1 controls SA signalling. SIZ1 interacts epistatically with PAD4 to regulate PR expression and disease resistance. Consistent with these observations, siz1 plants exhibited enhanced resistance to Pst DC3000 expressing avrRps4, a bacterial avirulence determinant that responds to the EDS1/PAD4-dependent TIR-NBS-type R gene. In contrast, siz1 plants were not resistant to Pst DC3000 expressing avrRpm1, a bacterial avirulence determinant that responds to the NDR1-dependent CC-NBS-type R gene. Jasmonic acid (JA)-induced PDF1.2 expression and susceptibility to Botrytis cinerea were unaltered in siz1 plants. Taken together, these results demonstrate that SIZ1 is required for SA and PAD4-mediated R gene signalling, which in turn confers innate immunity in Arabidopsis.
The Plant Journal 02/2007; 49(1):79-90. · 6.16 Impact Factor
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Kwang Sik Lee,
Bo Yeon Kim,
Hong Ja Kim,
Sook Jae Seo,
Hyung Joo Yoon,
Yong Soo Choi,
Iksoo Kim,
Yeon Soo Han,
Yeon Ho Je,
Sang Mong Lee, Doh Hoon Kim,
Hung Dae Sohn,
Byung Rae Jin
[show abstract]
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ABSTRACT: Transferrin in insects is known as an iron transporter, an antibiotic agent, a vitellogenin, and a juvenile hormone-regulated protein. We show here a novel functional role for insect transferrin. Stresses, such as iron overload, bacterial or fungal challenge, cold or heat shock, wounding, and H2O2 or paraquat exposure, cause upregulation of the beetle Apriona germari transferrin (AgTf) gene in the fat body and epidermis, and they cause increased AgTf protein levels. RNA interference (RNAi)-mediated AgTf reduction results in rapid induction of apoptotic cell death in the fat body during exposure to heat stress. The observed effect of AgTf RNAi indicates that AgTf inhibits heat stress-induced apoptotic cell death, suggesting a functional role for AgTf in defense and stress responses in the beetle.
Free Radical Biology and Medicine 11/2006; 41(7):1151-61. · 5.42 Impact Factor
