Project description:To address specificity of ALaP-seq for PMLwt, we performed genome-wide profiling of genomic regions associated with NLS-APEX or PMLca-APEX. Cells were treated with H2O2 to trigger labeling of chromatin with biotin (H2O2+). Experimental negative control for PMLca (H2O2-), where the H2O2 treatment was omitted, was also analyzed.
Project description:Stress granules are dynamic non-membrane bound organelles made up of untranslating messenger ribonucleoproteins (mRNPs) that form when cells integrate stressful environmental cues resulting in stalled translation initiation complexes. Although stress granules dramatically alter mRNA and protein localization, understanding these complexes has proven to be challenging through conventional imaging, purification, and crosslinking approaches. We therefore developed an RNA proximity labeling technique, APEX-Seq, which uses the ascorbate peroxidase APEX2 to probe the spatial organization of the transcriptome. We show that APEX-Seq can resolve the localization of RNAs within the cell and determine their enrichment or depletion near key RNA-binding proteins. Matching both the spatial transcriptome using APEX-seq, and the spatial proteome using APEX-mass spectrometry (APEX-MS) provide new insights into the organization of translation initiation complexes on active mRNAs, as well as revealing unanticipated complexity in stress granule contents, and provides a powerful approach to explore the spatial environment of macromolecules.
Project description:The root apex is an important section of the plant root, involved in environmental sensing and cellular development. Analyzing the gene profile of root apex in diverse environments is important and challenging, especially when the samples are limiting and precious, such as in spaceflight. The feasibility of using tiny root sections for transcriptome analysis was examined in this study.To understand the gene expression profiles of the root apex, Arabidopsis thaliana Col-0 roots were sectioned into Zone-I (0.5 mm, root cap and meristematic zone) and Zone-II (1.5 mm, transition, elongation and growth terminating zone). Gene expression was analyzed using microarray and RNA seq.Both the techniques, arrays and RNA-Seq identified 4180 common genes as differentially expressed (with > two-fold changes) between the zones. In addition, 771 unique genes and 19 novel TARs were identified by RNA-Seq as differentially expressed which were not detected in the arrays. Single root tip zones can be used for full transcriptome analysis; further, the root apex zones are functionally very distinct from each other. RNA-Seq provided novel information about the transcripts compared to the arrays. These data will help optimize transcriptome techniques for dealing with small, rare samples.
Project description:The root apex is an important section of the plant root, involved in environmental sensing and cellular development. Analyzing the gene profile of root apex in diverse environments is important and challenging, especially when the samples are limiting and precious, such as in spaceflight. The feasibility of using tiny root sections for transcriptome analysis was examined in this study.To understand the gene expression profiles of the root apex, Arabidopsis thaliana Col-0 roots were sectioned into Zone-I (0.5 mm, root cap and meristematic zone) and Zone-II (1.5 mm, transition, elongation and growth terminating zone). Gene expression was analyzed using microarray and RNA seq.Both the techniques, arrays and RNA-Seq identified 4180 common genes as differentially expressed (with > two-fold changes) between the zones. In addition, 771 unique genes and 19 novel TARs were identified by RNA-Seq as differentially expressed which were not detected in the arrays. Single root tip zones can be used for full transcriptome analysis; further, the root apex zones are functionally very distinct from each other. RNA-Seq provided novel information about the transcripts compared to the arrays. These data will help optimize transcriptome techniques for dealing with small, rare samples.