11:10-12:00, Rm 103

RNA biologyT-18-01Genome-wide function of Processing Bodies in mRNA decayJe-Hyun Yoon and Roy ParkerDepartment of Molecular and Cellular Biology and Howard Hughes Medical Institute, Universityof Arizona, Tucson, AZ 85721, USATranslation and mRNA degradation are intertwined and critical aspects of posttranscriptionalcontrol. A conserved component of the mRNA decapping machinery isEdc3, which binds the decapping enzyme and can enhance its activity, and plays animportant role in the assembly of P-bodies. Despite these roles, Edc3 is thought to onlydirectly affect the decay rates of two yeast mRNAs. By analysis of the transcriptome inedc3, strains we demonstrate that Edc3 modulates the levels and decay rates ofhundreds of yeast mRNAs by both promoting and inhibiting decapping in a transcript andgrowth condition specific manner. Moreover, accelerated decapping of specific mRNAs inedc3, strains is promoted by the mRNP aggregation driven by the Lsm4 protein. Theseresults demonstrate that Edc3 is a multifunctional protein with both positive and negativeeffects of decapping and that aggregation of mRNPs into larger complexes can influencethe rate of decapping.T-18-04Size constraint in the packaging of Turnip Yellow Mosaic Virus RNAHui-Bae Kim, Kwang-Hee Chae, Hyun-Il Shin and Tae-Ju ChoDepartment of Biochemistry, Chungbuk National University, Cheongju 361-763, KoreaTurnip yellow mosaic virus (TYMV) is a spherical plant virus that has a single 6.3 kbpositive strand RNA as a genome. The genomic RNA is presumed to be either packagedalone or co-packaged along with its 0.8 kb subgenomic RNA. Previously, we observedthat the genomic TYMV RNA containing a 1.8 kb GUS gene was efficiently encapsidated.Since size constraint has been reported for many spherical viruses, we were curiousabout how big an extra sequence could be inserted without affecting the virion assembly.To address this issue, we made several constructs where an extra sequence of varioussize was inserted into the TYMV genome. Northern blot analysis of the total andencapsidated RNAs of the recombinant TYMVs showed that replication became weakeras more extra sequence was inserted. The result also showed that 2.6 kb insertion wasnot tolerated as far as genomic RNA packaging is concerned. In contrast, therecombinant subgenomic RNA containing an extra sequence of up to 3.1 kb wasefficiently encapsidated. [Supported by a research fund (2010-0021868) from theNational Research Foundation of Korea]T-18-02Aberrant FGFR3 mRNA splicing in colorectal cancerWonmo Kang, Eunyi Jeon, Su-jin Lee, Jun-Hyuk JangDepartment of Biochemistry, Inha University School of Medicine, Incheon 400-712, KoreaA nested reverse transcription-PCR analysis of FGFR3 from human colorectalcarcinomas revealed novel mutant transcripts caused by aberrant splicing and activationof cryptic splice sequences. Two aberrantly spliced transcripts were detected with highfrequency in 50% of 36 primary tumors and in 60% of 10 human colorectal cancer celllines. Moreover, we found a novel splice variant of FGFR2 (FGFR2DIII) arising fromskipping exons 7-10, resulting in the deletion of Ig-like-III domain in humanchondrosarcoma cell. Sf9 cells expressing FGFR2DIII were able to bind FGF1, FGF2,and FGF7, leading to loss of ligand-binding specificity. Taken together, we propose thatmRNA splicing plays an important role in the regulation of FGFRs gene.T-18-05Microfluidic approach for quantitative analysis of rna within a singlecellDong Kyun Kim¹, Samuel Kim¹ , ², Hong Gil Nam¹ , ²and Nam Ki Lee¹ , ³¹School of Interdisciplinary Bioscience and Bioengineering, ²Department of Life Science,³Department of physics, Pohang University of Science and Technology (POSTECH), Pohang,KoreaWe present a method for directly counting RNA molecules obtained from individual cells.A microfluidic device with pneumatically actuated microvalves enables efficientmanipulation of single cells and their lysates, thereby minimizing dilution of analytes.Specific RNA molecules can be detected by hybridizing with fluorescently-labeled antisenseprobes. Microchip capillary electrophoresis allows not only the separation ofhybridized RNA molecules from fluorescent probes but also the differentiation of multipleRNA species based on their differences in electrophoretic mobilities. It is expected that,using this approach, RNA species of low abundance can be analyzed and the cell-to-cellvariation in RNA copy numbers in biological networks can be studied.T-18-03HnRNP Q mediates a rapid induction of p53 via IRES-dependenttranslation and induces apoptosisDo-Yeon Kim¹, Wanil Kim¹, Kyung-Chul Woo¹, Kyung-Ha Lee¹, Sung-Hoon Kim²,Hwa-Rim Lee²and Kyong-Tai Kim¹ , ² , ³¹Department of Life Science, Division of Molecular and Life Science, Pohang University of Scienceand Technology, Pohang, Gyeong-Buk, Korea, ²School of Interdisciplinary Bioscience andBioengineering, Pohang University of Science and Technology, Pohang, Gyeong-Buk, Korea,³Division of Integrative Bioscience & Biotechnology, Pohang University of Science andTechnology, Pohang, Gyeong -Buk, Koreap53 is a general regulator in cell cycle progression and apoptosis. In response to severalcellular stresses, the rapid accumulation of p53 is an important step in cell fate decision.Several lines of evidence suggest that the upregulation of p53 protein level isaccompanied by the enhancement of p53 transcription and/or stabilization of p53 proteinvia dissociation of MDM2. Even though it is clear that the increase of translation efficiencyof p53 may also contribute to the abundance of p53 protein, mechanisms controllingtranslation initiation of p53 are not clearly understood yet. Here we demonstrate that p53is immediately accumulated, responding to cellular stress, and this phenomenon is mainlycontrolled by cap-independent translation initiation. We also identify that Heterogeneousnuclear ribonucleoprotein (hnRNP) Q binds to 5’untranslated region (UTR) of p53mRNA and an internal ribosomal entry site (IRES) mediated translation of p53 declineswhen hnRNP Q is downregulated. Based on these results, we propose that hnRNP Qcontrols a rapid accumulation of p53 protein via IRES-dependent manner and isnecessary for apoptosis induction.T-18-06Coordinated regulation of MAPK signaling pathway and miRNA inresponse to ionizing radiation in lung cancer cellsHimanshu Arora¹ , # , Rehana Qureshi¹ , # , Ae-Kyoung Park², Woong-Yang Park¹ , ² , *¹Departments of Biomedical Sciences, Biochemistry and Molecular Biology, ²Genomics CoreLaboratory, Seoul National University College of Medicine, Seoul 110-799, Korea, ³Ministry ofHealth Key Laboratory of Radiobiology, Jilin University, Changchun 130021, China, ⁴Departmentof Biochemistry, Ewha Women University College of Medicine, Seoul 158-907, KoreaThe ionizing radiation induced DNA damage response activates several pathways thatregulate cell cycle and allow DNA repair. MicroRNAs are short 20-22 nucleotidesequences, which play a crucial role in various cancer types. To examine miRNAmediatedregulation of the cellular responses to ionizing radiation (IR), we analyzed timedependentchanges in miRNA expression profiles upon 2 Gy γ-irradiation in radioresistantH1299 and radiosensitive H460 human lung cancer cell lines using DNA microarray. Weidentified and selected differentially expressed miRNAs based on ANOVA analysis inH1299 and H460 cell lines. From enrichment analysis and on the fact that DDR is notsolely dependent upon p53 and in the absence of p53 the MAPK pathway is essential forsurvival in response to DNA damage causing agents, we selected MAPK signalingpathway for further studies. Concurrent analysis of mRNA and miRNA expression profilesrevealed that upon 2 Gy γ-irradiation, most of target genes in MAPK signaling pathwaywere differentially regulated in H1299 and H460 cells. We confirmed these findings byfurther experiments and from results, we propose that there exists a coordinatedregulation between microRNA and MAPK signaling genes in response to ionizingradiations.336 Korean Society for Biochemistry and Molecular Biology