%0 Journal Article %J Dev Cell %D 2016 %T Establishment of Expression in the SHORTROOT-SCARECROW Transcriptional Cascade through Opposing Activities of Both Activators and Repressors %A Sparks, E. E. %A Drapek, C. %A Gaudinier, A. %A Li, S. %A Ansariola, M. %A Shen, N. %A Hennacy, J. H. %A Zhang, J. %A Turco, G. %A Petricka, J. J. %A Foret, J. %A Hartemink, A. J. %A Gordan, R. %A Megraw, M. %A Brady, S. M. %A Benfey, P. N. %K Arabidopsis Proteins/ genetics/ metabolism %K Arabidopsis/ genetics/growth & development/ metabolism %K Computer Simulation %K Gene Expression Regulation, Plant %K Gene Regulatory Networks %K Genes, Plant %K Genes, Reporter %K Genes, Synthetic %K Models, Genetic %K Plant Roots/cytology/metabolism %K Plants, Genetically Modified %K Promoter Regions, Genetic %K Repressor Proteins/genetics/metabolism %K Trans-Activators/genetics/metabolism %K Transcription Factors/ genetics/ metabolism %K Two-Hybrid System Techniques %X

Tissue-specific gene expression is often thought to arise from spatially restricted transcriptional cascades. However, it is unclear how expression is established at the top of these cascades in the absence of pre-existing specificity. We generated a transcriptional network to explore how transcription factor expression is established in the Arabidopsis thaliana root ground tissue. Regulators of the SHORTROOT-SCARECROW transcriptional cascade were validated in planta. At the top of this cascade, we identified both activators and repressors of SHORTROOT. The aggregate spatial expression of these regulators is not sufficient to predict transcriptional specificity. Instead, modeling, transcriptional reporters, and synthetic promoters support a mechanism whereby expression at the top of the SHORTROOT-SCARECROW cascade is established through opposing activities of activators and repressors.

%B Dev Cell %V 39 %P 585-596 %8 12/2016 %@ 1878-1551 (Electronic)1534-5807 (Linking) %G eng %U https://doi.org/10.1016/j.devcel.2016.09.031 %! Developmental cell %0 Journal Article %J Proc Natl Acad Sci U S A %D 2012 %T The protein expression landscape of the Arabidopsis root. %A Petricka, Jalean J %A Schauer, Monica A %A Megraw, Molly %A Breakfield, Natalie W %A Thompson, J Will %A Georgiev, Stoyan %A Soderblom, Erik J %A Ohler, Uwe %A Moseley, Martin Arthur %A Grossniklaus, Ueli %A Benfey, Philip N %K Arabidopsis %K Arabidopsis Proteins %K Base Sequence %K Chromatography, Liquid %K DNA Primers %K Gene Expression Profiling %K Plant Roots %K Plants, Genetically Modified %K Protein Array Analysis %K Protein Interaction Mapping %K Proteome %K Proteomics %K RNA, Plant %K Tandem Mass Spectrometry %X

Because proteins are the major functional components of cells, knowledge of their cellular localization is crucial to gaining an understanding of the biology of multicellular organisms. We have generated a protein expression map of the Arabidopsis root providing the identity and cell type-specific localization of nearly 2,000 proteins. Grouping proteins into functional categories revealed unique cellular functions and identified cell type-specific biomarkers. Cellular colocalization provided support for numerous protein-protein interactions. With a binary comparison, we found that RNA and protein expression profiles are weakly correlated. We then performed peak integration at cell type-specific resolution and found an improved correlation with transcriptome data using continuous values. We performed GeLC-MS/MS (in-gel tryptic digestion followed by liquid chromatography-tandem mass spectrometry) proteomic experiments on mutants with ectopic and no root hairs, providing complementary proteomic data. Finally, among our root hair-specific proteins we identified two unique regulators of root hair development.

%B Proc Natl Acad Sci U S A %V 109 %P 6811-8 %8 2012 May 1 %G eng %N 18 %R 10.1073/pnas.1202546109