11:10-12:00, Rm 103

Plant biologyI-17-01Functional characterization of AtSRip1 in vivoDae-Won Kim, Hyeong-Seop Jeong, Sung-Min Hwang and Jeong Dong BahkDivision of Applied Life Sciences (BK21), Graduate School of Gyeongsang National University,Jinju 660-701, KoreaThe Nuclear RNA-binding protein families are important factors in the regulation of manypost-transcriptional steps in gene expression, however, their functions remain unclear inplants yet. Previously, we have characterized a putative RNA binding protein, AtSRip1,which was essential for normal growth in plants. The knock-out mutants exhibited a semidwarfphenotype and abnormal development of rosette leaves. In this study, thesubcellular localization and interaction partner of AtSRip1 were examined in protoplastsand living cells, respectively. The complete overlapped signal of GFP-AtSRip1 with DAPIwas appeared in nucleus, prominently in the speckle compartment. Moreover, it wasdemonstrated that RS-like domain is necessary for nuclear localization in Arabidopsisprotoplasts. The yeast two hybrid screens revealed that AtSRip1 interacts with SR1 andSRm102, which are important for the splisosome assembly and promote the binding ofU2 snRNP to pre-mRNA, respectively. This is also confirmed further by BiFC analysisusing tobacco living cells. In conclusion, this suggests that AtSRip1 as a RNA bindingprotein might play a role in pre-mRNA splicing in nucleus and developmental processesin Arabidopsis. [Supported by a grant from the BK21 program at Gyeongsang NationalUniversity]I-17-04A hot pepper heat shock transcription factor (CaHSTF1) plays a positiverole in plant immune responseInseok Lee, Lamee Choi, Gil-Je Lee, Young Jin Kim and Kyung-Hee PaekPlant Signaling Network Research Center, School of Life Sciences and Biotechnology, KoreaUniversity, Seoul 136-701, KoreaSeveral layers of plant defense responses are triggered upon pathogenic infection. Thegene expression change of transcription factors is a critical component of theseresponses. In this report, several kinds of transcription factors which were specificallyinduced during hypersensitive response were isolated by microarray after TMV-P0infection in Capsicum annuum cv. Bugang. One of these transcription factors exhibitingincreased activity 48 hrs after infection, contained nucleotide sequence similarity to anArabidopsis thaliana heat shock transcription factor, AT-HSFB3. CaHSTF1 did not showany significant changes in expression under heat shock treatment conditions. However,higher CaHSTF1 expression was detected by TMV-P0 infection at high temperature (34℃) compared to normal growth temperature (24℃). The knockdown of CaHSTF1expression in pepper plants by virus-induced gene silencing (VIGS) caused a decrease inthe expression of TMV-P0-triggered PR genes, suggesting CaHSTF1as a positiveregulator in the plant defense response. VIGS knockdown of CaWRKYd, a representativedefense related transcription factor gene, caused downregulation of CaHSTF1 at thetranscriptional level upon TMV-P0 infection, suggesting that CaHSTF1 functions as apositive regulator in defense mechanisms.I-17-02Role of AtAIT2, an ABA-inducible transcription factor 2 under droughtand salt stressed conditionsHyeong-Seop Jeong, Dae-Won Kim, Sung-Min Hwang and Jeong Dong BahkDivision of Applied Life Sciences (BK21), Graduate School of Gyeongsang National University,Jinju 660-701, KoreaABA as one of the phytohormones is an important regulator at various plant growth anddevelopment stages. Here, we report that an ABA-inducible transcription factor 2 (AIT2),a member of Hsfs family, is involved in the abiotic stress responses by integratingdownstream stress-related genes. Arabidopsis thaliana contains 21 Hsf genes. AtAIT2belongs to the class A among three different classes (A, B and C). AtAIT2 contains aDNA-binding domain, an oligomerization domain, a nuclear localization sequence and anuclear export sequence. RT-PCR analysis indicated that AtAIT2 was activated underABA treatment and abiotic stresses such as high salts and drought. Time-course analysisof gene expression with ABA and some abiotic stresses including cold, drought, heat andNaCl treatments revealed that transcripts of AtAIT2 were detected rapidly with ABA, cold,drought and NaCl treatment whereas they was slow with heat treatment. In addition,transgenic Arabidopsis overexpressing AtAIT2 showed hypersensitivity to ABA againstwild-type during seed germination stage. Taken together, it is suggested that AtAIT2 isregulated by ABA and plays a significant role in drought and salt stress responses.[Supported by a grant from the BK21 program at Gyeongsang National University]I-17-05Expression, purification and characterization of a new type methioninesulfoxide reducatase A from tomato (Solanum lycopersicum)Changbo Dai and Myeong-Hyeon Wang*Department of Medical Biotechnology, College of Biomedical Science, Kangwon NationalUniversity, Chuncheon, Gangwon-do 200-071, KoreaMethionine sulfoxide reductase A (MSRA) is a ubiquitous enzyme, which has the ability toreduce S enantiomer of methionine sulfoxide (MetSO) to methionine (Met), and found tobe involved in defense against oxidative damage of cells. Here, we isolated a new type ofMSRA, named as SlMSRA2, from Micro-tomato (Solanum lycopersicum Mill.)Interestingly, the amino acid sequences of MSRA2 were truncated at C terminal incomparison to the plant MSRAs reported. To characterize MSRA2, we subcloned thecoding sequence into pET 28a(+) expression vector and introduced into Escherichia coliBL21(DE3). After expression, purification and refolding, the final purified protein wasassayed using reverse phase HPLC with different substrates. The recombinant proteinexhibited an absolute specificity for methionine-S-sulfoxide, but not toward methionine-Rsulfoxide.Moreover, the enzyme was able to converse both free and protein-bounddabsyl-MetSO to dabsyl-Met in the presence of DTT. In addition, analyzing reactionconditions of MSRA2 revealed that the optimal pH, temperature was around 8.5, and 25℃,respectively. Km value of the enzyme was calculated to be 352 ± 25 µM while Vmaxvalue was approximately 477 ± 65 pmol min-1.I-17-03Construction and characterization of a full-length cdna library for thecitrus platymamma hort. ex. tanakaSung Jin Chung¹, Song-I Han², Seong-Beom Jin³, Byoung-Jun Yoon³, Yong-WooKim¹, Key-Zung Riu¹ , ² , ³and Jae-Hoon Kim¹ , ² , ³ , *¹Research Institute for Subtropical Horticulture, Jeju National University, Jeju 690-756,²Department of Biotechnology, Jeju National University, Jeju 690-756, and ³Citrus GeneticResources Bank, Jeju National University, Jeju 690-756, KoreaCitrus is one of the most important fruits plant in the world for fruits and other products,such as juice, soap, cosmetics, etc. Especially, C. platymamma Hort. ex. Tanaka(Byungkyool) has been used in traditional Asian medicine for centuries. Libraries of cDNAclones are valuable resources for analyzing the expression, structure and regulation ofgenes, and for studying protein functions and interactions. In this study, we isolated totalRNA from immature fruit of Byungkyool and constructed of a full-length cDNA library, anaverage cDNA insert of about 1.0 kb. Comparative analysis between the derivedsequences from Citrus and Arabidopsis, rice or other plants data revealed that somespecific genes were involved in our collection and a large part of them could be annotatedto unknown functions. This citrus full-length cDNA library reported in this study will serveas a useful resource for gene discovery from citrus and will also aid a precise annotationof the citrus genome. Acknowledgment : This work was supported from Citrus GeneticResources Bank, Jeju National University, and Priority Research Centers Programthrough the National Research Foundation of Korea (NRF) funded by the Ministry ofEducation, Science and Technology (2010-0029630).I-17-06Inhibition the pro-inflammatory cytokine and oxidative stress by ethylacetate fraction of Sonchus asper in LPS-induced RAW264.7 macrophageChangbo Dai, Lan Wang and Myeong-Hyeon WangDepartment of Medical Biotechnology, College of Biomedical Science, Kangwon NationalUniversity, Chuncheon, Gangwon 200-701, KoreaSonchus asper has been extensively used as alternative to treat bronchitis, asthma,wound, burns and cough. The EtOAc fraction of S. asper significantly inhibited NOproduction in RAW264.7 cell. The inhibition was associated with suppression theoxidative stress as evidenced by increasing endoxigenous SOD activity and intracellularGSH levels, decreasing the ROS generation and lipid peroxidation formation, restoringmitochondrial membrane potential. Additionally, semi-quantitative RT-PCR revealedreduced expression of pro-inflammatory cytokine, iNOS, COX-2, TNF-α, IL-1βand IL-6 ina dose-dependent manner and enhanced expression of antioxidant gene MnSOD andHO-1 in RAW264.7 cells treated with EtOAc fraction of S. asper. Furthermore, HPLCfingerprint identify the rutin, caffeic acid, commric acid, gallic acid present in the EtOAcfraction of S. asper. Conclusively, the findings imply the anti-inflammtory effect of EtOAcfraction of S. asper on LPS-stimualted RAW264.7 by suppression the oxidative stress.258 Korean Society for Biochemistry and Molecular Biology