01085nas a2200373 4500008004100000245010300041210006900144260001200213490000600225100002100231700002100252700001900273700001700292700001800309700002200327700001900349700001600368700002200384700002000406700002100426700001600447700001700463700001500480700002000495700002000515700001300535700001400548700001800562700001700580700001600597700001900613700001700632856006200649 2019 eng d00aArabidopsis bioinformatics resources: The current state, challenges, and priorities for the future0 aArabidopsis bioinformatics resources The current state challenge c01/20190 v31 aDoherty, Colleen1 aFriesner, Joanna1 aGregory, Brian1 aLoraine, Ann1 aMegraw, Molly1 aProvart, Nicholas1 aSlotkin, Keith1 aTown, Chris1 aAssmann, Sarah, M1 aAxtell, Michael1 aBerardini, Tanya1 aChen, Sixue1 aGehan, Malia1 aHuala, Eva1 aJaiswal, Pankaj1 aLarson, Stephen1 aLi, Song1 aMay, Sean1 aMichael, Todd1 aPires, Chris1 aTopp, Chris1 aWalley, Justin1 aWurtele, Eve uhttps://onlinelibrary.wiley.com/doi/full/10.1002/pld3.10902502nas a2200325 4500008004100000022001400041245012000055210006900175260001300244300001100257490000600268520148900274653002501763653001601788653002501804653002101829653003801850653001201888653003301900100002501933700002101958700002801979700002002007700001902027700002502046700001802071700001802089700002102107856004802128 2015 eng d a1752-986700aEnvironmental stresses modulate abundance and timing of alternatively spliced circadian transcripts in Arabidopsis.0 aEnvironmental stresses modulate abundance and timing of alternat c2015 Feb a207-270 v83 a
Environmental stresses profoundly altered accumulation of nonsense mRNAs including intron-retaining (IR) transcripts in Arabidopsis. Temporal patterns of stress-induced IR mRNAs were dissected using both oscillating and non-oscillating transcripts. Broad-range thermal cycles triggered a sharp increase in the long IR CCA1 isoforms and altered their phasing to different times of day. Both abiotic and biotic stresses such as drought or Pseudomonas syringae infection induced a similar increase. Thermal stress induced a time delay in accumulation of CCA1 I4Rb transcripts, whereas functional mRNA showed steady oscillations. Our data favor a hypothesis that stress-induced instabilities of the central oscillator can be in part compensated through fluctuations in abundance and out-of-phase oscillations of CCA1 IR transcripts. Taken together, our results support a concept that mRNA abundance can be modulated through altering ratios between functional and nonsense/IR transcripts. SR45 protein specifically bound to the retained CCA1 intron in vitro, suggesting that this splicing factor could be involved in regulation of intron retention. Transcriptomes of nonsense-mediated mRNA decay (NMD)-impaired and heat-stressed plants shared a set of retained introns associated with stress- and defense-inducible transcripts. Constitutive activation of certain stress response networks in an NMD mutant could be linked to disequilibrium between functional and nonsense mRNAs.
10aAlternative Splicing10aArabidopsis10aArabidopsis Proteins10aCircadian Clocks10aGene Expression Regulation, Plant10aIntrons10aNonsense Mediated mRNA Decay1 aFilichkin, Sergei, A1 aCumbie, Jason, S1 aDharmawardhana, Palitha1 aJaiswal, Pankaj1 aChang, Jeff, H1 aPalusa, Saiprasad, G1 aReddy, A, S N1 aMegraw, Molly1 aMockler, Todd, C uhttp://megraw.cgrb.oregonstate.edu/node/31502170nas a2200217 4500008004100000022001400041245012000055210006900175260001500244520145100259100002501710700002101735700002701756700002001783700001901803700002501822700001801847700001801865700002101883856004801904 2014 eng d a1752-986700aEnvironmental Stresses Modulate Abundance and Timing of Alternatively Spliced Circadian Transcripts in Arabidopsis.0 aEnvironmental Stresses Modulate Abundance and Timing of Alternat c2014 Nov 33 aEnvironmental stresses profoundly altered accumulation of nonsense mRNAs including intron retaining (IR) transcripts in Arabidopsis. Temporal patterns of stress-induced IR mRNAs were dissected using both oscillating and non-oscillating transcripts. Broad range thermal cycles triggered a sharp increase in the long intron retaining CCA1 isoforms and altered their phasing to different times of day. Both abiotic and biotic stresses such as drought or P. syringae infection induced similar increase. Thermal stress induced a time delay in accumulation of CCA1 I4Rb transcripts whereas functional mRNA showed steady oscillations. Our data favor a hypothesis that stress-induced instabilities of the central oscillator can be in part compensated through fluctuations in abundance and out of phase oscillations of CCA1 IR transcripts. Altogether, our results support a concept that mRNA abundance can be modulated through altering ratios between functional and nonsense/IR transcripts. SR45 protein specifically bound to the retained CCA1 intron in vitro, suggesting that this splicing factor could be involved in regulation of intron retention. Transcriptomes of NMD-impaired and heat-stressed plants shared a set of retained introns associated with stress- and defense-inducible transcripts. Constitutive activation of certain stress response networks in an NMD mutant could be linked to disequilibrium between functional and nonsense mRNAs.
1 aFilichkin, Sergei, A1 aCumbie, Jason, S1 aDharmawadhana, Palitha1 aJaiswal, Pankaj1 aChang, Jeff, H1 aPalusa, Saiprasad, G1 aReddy, A, S N1 aMegraw, Molly1 aMockler, Todd, C uhttp://megraw.cgrb.oregonstate.edu/node/31702389nas a2200433 4500008004100000022001400041245007000055210006600125260001600191300000800207490000600215520115000221653001601371653002501387653003001412653002901442653001401471653001601485653003101501653002001532653002601552653003301578100002201611700001801633700001801651700002501669700001601694700001901710700001601729700001501745700002901760700001501789700002201804700001501826700001701841700002701858700002201885856004801907 2011 eng d a1744-429200aA stele-enriched gene regulatory network in the Arabidopsis root.0 asteleenriched gene regulatory network in the Arabidopsis root c2011 Jan 18 a4590 v73 aTightly controlled gene expression is a hallmark of multicellular development and is accomplished by transcription factors (TFs) and microRNAs (miRNAs). Although many studies have focused on identifying downstream targets of these molecules, less is known about the factors that regulate their differential expression. We used data from high spatial resolution gene expression experiments and yeast one-hybrid (Y1H) and two-hybrid (Y2H) assays to delineate a subset of interactions occurring within a gene regulatory network (GRN) that determines tissue-specific TF and miRNA expression in plants. We find that upstream TFs are expressed in more diverse cell types than their targets and that promoters that are bound by a relatively large number of TFs correspond to key developmental regulators. The regulatory consequence of many TFs for their target was experimentally determined using genetic analysis. Remarkably, molecular phenotypes were identified for 65% of the TFs, but morphological phenotypes were associated with only 16%. This indicates that the GRN is robust, and that gene expression changes may be canalized or buffered.
10aArabidopsis10aArabidopsis Proteins10aGene Expression Profiling10aGene Regulatory Networks10aMicroRNAs10aPlant Roots10aReproducibility of Results10aSystems Biology10aTranscription Factors10aTwo-Hybrid System Techniques1 aBrady, Siobhan, M1 aZhang, Lifang1 aMegraw, Molly1 aMartinez, Natalia, J1 aJiang, Eric1 aYi, Charles, S1 aLiu, Weilin1 aZeng, Anna1 aTaylor-Teeples, Mallorie1 aKim, Dahae1 aAhnert, Sebastian1 aOhler, Uwe1 aWare, Doreen1 aWalhout, Albertha, J M1 aBenfey, Philip, N uhttp://megraw.cgrb.oregonstate.edu/node/32202835nas a2200337 4500008004100000022001400041245008700055210006900142260001300211300001100224490000700235520183700242653002102079653002302100653000802123653003102131653001802162653001102180653003002191653002202221653001302243653002602256653003402282653002702316100001802343700002202361700002102383700001502404700003002419856004802449 2009 eng d a1088-905100aA transcription factor affinity-based code for mammalian transcription initiation.0 atranscription factor affinitybased code for mammalian transcript c2009 Apr a644-560 v193 aThe recent arrival of large-scale cap analysis of gene expression (CAGE) data sets in mammals provides a wealth of quantitative information on coding and noncoding RNA polymerase II transcription start sites (TSS). Genome-wide CAGE studies reveal that a large fraction of TSS exhibit peaks where the vast majority of associated tags map to a particular location ( approximately 45%), whereas other active regions contain a broader distribution of initiation events. The presence of a strong single peak suggests that transcription at these locations may be mediated by position-specific sequence features. We therefore propose a new model for single-peaked TSS based solely on known transcription factors (TFs) and their respective regions of positional enrichment. This probabilistic model leads to near-perfect classification results in cross-validation (auROC = 0.98), and performance in genomic scans demonstrates that TSS prediction with both high accuracy and spatial resolution is achievable for a specific but large subgroup of mammalian promoters. The interpretable model structure suggests a DNA code in which canonical sequence features such as TATA-box, Initiator, and GC content do play a significant role, but many additional TFs show distinct spatial biases with respect to TSS location and are important contributors to the accurate prediction of single-peak transcription initiation sites. The model structure also reveals that CAGE tag clusters distal from annotated gene starts have distinct characteristics compared to those close to gene 5'-ends. Using this high-resolution single-peak model, we predict TSS for approximately 70% of mammalian microRNAs based on currently available data.
[Links to Tools and Supplementary Materials]
10aBase Composition10aDatabases, Genetic10aDNA10aGene Expression Regulation10aGenome, Human10aHumans10aPromoter Regions, Genetic10aRNA Polymerase II10aTATA Box10aTranscription Factors10aTranscription Initiation Site10aTranscription, Genetic1 aMegraw, Molly1 aPereira, Fernando1 aJensen, Shane, T1 aOhler, Uwe1 aHatzigeorgiou, Artemis, G uhttp://megraw.cgrb.oregonstate.edu/node/32603230nas a2200709 4500008004100000022001400041245010600055210006900161260001600230300001100246490000800257520120600265653001801471653002001489653002401509653002101533653001101554653003001565653004301595653001801638653001101656653001401667653002101681653002201702653002101724653001901745653002201764100001501786700002101801700001801822700002601840700001901866700001401885700002001899700002501919700002301944700002001967700002601987700002102013700001702034700001802051700001502069700001602084700001602100700002402116700001802140700002402158700002902182700002002211700002502231700002402256700002202280700001802302700001802320700002002338700002202358700002302380700003002403700002002433700001902453856004802472 2008 eng d a1091-649000aGenomic and epigenetic alterations deregulate microRNA expression in human epithelial ovarian cancer.0 aGenomic and epigenetic alterations deregulate microRNA expressio c2008 May 13 a7004-90 v1053 aMicroRNAs (miRNAs) are an abundant class of small noncoding RNAs that function as negative gene regulators. miRNA deregulation is involved in the initiation and progression of human cancer; however, the underlying mechanism and its contributions to genome-wide transcriptional changes in cancer are still largely unknown. We studied miRNA deregulation in human epithelial ovarian cancer by integrative genomic approach, including miRNA microarray (n = 106), array-based comparative genomic hybridization (n = 109), cDNA microarray (n = 76), and tissue array (n = 504). miRNA expression is markedly down-regulated in malignant transformation and tumor progression. Genomic copy number loss and epigenetic silencing, respectively, may account for the down-regulation of approximately 15% and at least approximately 36% of miRNAs in advanced ovarian tumors and miRNA down-regulation contributes to a genome-wide transcriptional deregulation. Last, eight miRNAs located in the chromosome 14 miRNA cluster (Dlk1-Gtl2 domain) were identified as potential tumor suppressor genes. Therefore, our results suggest that miRNAs may offer new biomarkers and therapeutic targets in epithelial ovarian cancer.
10aDNA, Neoplasm10aDown-Regulation10aEpigenesis, Genetic10aEpithelial Cells10aFemale10aGene Expression Profiling10aGene Expression Regulation, Neoplastic10aGenome, Human10aHumans10aMicroRNAs10aNeoplasm Staging10aOvarian Neoplasms10aRibonuclease III10aRNA, Messenger10aSurvival Analysis1 aZhang, Lin1 aVolinia, Stefano1 aBonome, Tomas1 aCalin, George, Adrian1 aGreshock, Joel1 aYang, Nuo1 aLiu, Chang-Gong1 aGiannakakis, Antonis1 aAlexiou, Pangiotis1 aHasegawa, Kosei1 aJohnstone, Cameron, N1 aMegraw, Molly, S1 aAdams, Sarah1 aLassus, Heini1 aHuang, Jia1 aKaur, Sippy1 aLiang, Shun1 aSethupathy, Praveen1 aLeminen, Arto1 aSimossis, Victor, A1 aSandaltzopoulos, Raphael1 aNaomoto, Yoshio1 aKatsaros, Dionyssios1 aGimotty, Phyllis, A1 aDeMichele, Angela1 aHuang, Qihong1 aBützow, Ralf1 aRustgi, Anil, K1 aWeber, Barbara, L1 aBirrer, Michael, J1 aHatzigeorgiou, Artemis, G1 aCroce, Carlo, M1 aCoukos, George uhttp://megraw.cgrb.oregonstate.edu/node/32801853nas a2200337 4500008004100000022001400041245005600055210005500111260001300166300001100179490000700190520089800197653001601095653001801111653001801129653002301147653002801170653001701198653001401215653003001229653001301259653002601272653003401298100001801332700001901350700002401369700002101393700002301414700003001437856004801467 2006 eng d a1355-838200aMicroRNA promoter element discovery in Arabidopsis.0 aMicroRNA promoter element discovery in Arabidopsis c2006 Sep a1612-90 v123 aIn this study we present a method of identifying Arabidopsis miRNA promoter elements using known transcription factor binding motifs. We provide a comparative analysis of the representation of these elements in miRNA promoters, protein-coding gene promoters, and random genomic sequences. We report five transcription factor (TF) binding motifs that show evidence of overrepresentation in miRNA promoter regions relative to the promoter regions of protein-coding genes. This investigation is based on the analysis of 800-nucleotide regions upstream of 63 experimentally verified Transcription Start Sites (TSS) for miRNA primary transcripts in Arabidopsis. While the TATA-box binding motif was also previously reported by Xie and colleagues, the transcription factors AtMYC2, ARF, SORLREP3, and LFY are identified for the first time as overrepresented binding motifs in miRNA promoters.
10aArabidopsis10aBase Sequence10aBinding Sites10aDatabases, Genetic10aFeedback, Physiological10aGenes, Plant10aMicroRNAs10aPromoter Regions, Genetic10aTATA Box10aTranscription Factors10aTranscription Initiation Site1 aMegraw, Molly1 aBaev, Vesselin1 aRusinov, Ventsislav1 aJensen, Shane, T1 aKalantidis, Kriton1 aHatzigeorgiou, Artemis, G uhttp://megraw.cgrb.oregonstate.edu/node/331