Abstract
RNA molecules form complex networks of molecular interactions that are central to their function and to cellular architecture. But these interaction networks are difficult to probe in situ. Here, we introduce Oligonucleotide-mediated proximity-interactome MAPping (O-MAP), a method for elucidating the biomolecules near an RNA of interest, within its native context. O-MAP uses RNA-fluorescence in situ hybridization-like oligonucleotide probes to deliver proximity-biotinylating enzymes to a target RNA in situ, enabling nearby molecules to be enriched by streptavidin pulldown. This induces exceptionally precise biotinylation that can be easily optimized and ported to new targets or sample types. Using the noncoding RNAs 47S, 7SK and Xist as models, we develop O-MAP workflows for discovering RNA-proximal proteins, transcripts and genomic loci, yielding a multiomic characterization of these RNAs’ subcellular compartments and new regulatory interactions. O-MAP requires no genetic manipulation, uses exclusively off-the-shelf parts and requires orders of magnitude fewer cells than established methods, making it accessible to most laboratories.
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Data availability
MS data are available on MASSIVE under accession number MSV000094186. RNA-seq and DNA-seq data are available on the Gene Expression Omnibus under SuperSeries accession number GSE217566. Raw imaging files used in this work are available upon request. HyPro-seq data were downloaded from the European Nucleotide Archive (ENA) under accession number PRJEB44394; NAD Fractionation DNA-seq data were downloaded from the ENA under accession number PRJEB2031. Genome assemblies hg38 (human) and mm10 (mouse) were used for alignment. Gene sets used in ROC analysis were assembled from data provided by the HPA (for 47S O-MAP)91 and the Jax Mouse Genome Informatics database (for Xist O-MAP)92. Source data are provided with this paper.
Code availability
Settings used for routine computational analyses (for example, high-throughput sequencing alignment and quantification) are described in detail in the Methods. Code used for k-medoid clustering (Fig. 3i and Supplementary Fig. 10), Xi allelic proportion analysis (Fig. 6c) and statistical testing of HeLa NADs (Fig. 6f) is available on the GitHub repository of the laboratory of D.M.S. via https://github.com/SheqLab/Tsue_Kania_et_al_2024_OMAP_paper/.
References
Muller-McNicoll, M. & Neugebauer, K. M. How cells get the message: dynamic assembly and function of mRNA-protein complexes. Nat. Rev. Genet. 14, 275–287 (2013).
Roden, C. & Gladfelter, A. S. RNA contributions to the form and function of biomolecular condensates. Nat. Rev. Mol. Cell Biol. 22, 183–195 (2021).
Quinodoz, S. A. & Guttman, M. Essential roles for RNA in shaping nuclear organization. Cold Spring Harb. Perspect. Biol. 14, a039719 (2022).
Dundr, M. & Misteli, T. Biogenesis of nuclear bodies. Cold Spring Harb. Perspect. Biol. 2, a000711 (2010).
Hirose, T., Ninomiya, K., Nakagawa, S. & Yamazaki, T. A guide to membraneless organelles and their various roles in gene regulation. Nat. Rev. Mol. Cell Biol. 24, 288–304 (2023).
Simon, M. D. & Machyna, M. Principles and practices of hybridization capture experiments to study long noncoding RNAs that act on chromatin. Cold Spring Harb. Perspect. Biol. 11, a032276 (2019).
McHugh, C. A. & Guttman, M. RAP-MS: a method to identify proteins that interact directly with a specific RNA molecule in cells. Methods Mol. Biol. 1649, 473–488 (2018).
Chu, C. & Chang, H. Y. ChIRP-MS: RNA-directed proteomic discovery. Methods Mol. Biol. 1861, 37–45 (2018).
Mili, S. & Steitz, J. A. Evidence for reassociation of RNA-binding proteins after cell lysis: implications for the interpretation of immunoprecipitation analyses. RNA 10, 1692–1694 (2004).
Qin, W., Cho, K. F., Cavanagh, P. E. & Ting, A. Y. Deciphering molecular interactions by proximity labeling. Nat. Methods 18, 133–143 (2021).
Kaewsapsak, P., Shechner, D. M., Mallard, W., Rinn, J. L. & Ting, A. Y. Live-cell mapping of organelle-associated RNAs via proximity biotinylation combined with protein-RNA crosslinking. eLife 6, e29224 (2017).
Ramanathan, M. et al. RNA-protein interaction detection in living cells. Nat. Methods 15, 207–212 (2018).
Han, Y. et al. Directed evolution of split APEX2 peroxidase. ACS Chem. Biol. 14, 619–635 (2019).
Han, S. et al. RNA-protein interaction mapping via MS2- or Cas13-based APEX targeting. Proc. Natl Acad. Sci. USA 117, 22068–22079 (2020).
Lobingier, B. T. et al. An approach to spatiotemporally resolve protein interaction networks in living cells. Cell 169, 350–360 (2017).
Carter, D., Chakalova, L., Osborne, C. S., Dai, Y. F. & Fraser, P. Long-range chromatin regulatory interactions in vivo. Nat. Genet. 32, 623–626 (2002).
Yap, K., Chung, T. H. & Makeyev, E. V. Hybridization-proximity labeling reveals spatially ordered interactions of nuclear RNA compartments. Mol. Cell 82, 463–478 (2022).
Raj, A. & Rinn, J. L. Illuminating genomic dark matter with RNA imaging. Cold Spring Harb. Perspect. Biol. 11, a032094 (2019).
Beliveau, B. J. et al. OligoMiner provides a rapid, flexible environment for the design of genome-scale oligonucleotide in situ hybridization probes. Proc. Natl Acad. Sci. USA 115, E2183–E2192 (2018).
Pederson, T. The nucleolus. Cold Spring Harb. Perspect. Biol. 3, a000638 (2011).
Padovan-Merhar, O. et al. Single mammalian cells compensate for differences in cellular volume and DNA copy number through independent global transcriptional mechanisms. Mol. Cell 58, 339–352 (2015).
Raap, A. K. et al. Ultra-sensitive FISH using peroxidase-mediated deposition of biotin- or fluorochrome tyramides. Hum. Mol. Genet. 4, 529–534 (1995).
Chen, Y. et al. Mapping 3D genome organization relative to nuclear compartments using TSA-Seq as a cytological ruler. J. Cell Biol. 217, 4025–4048 (2018).
Beliveau, B. J. et al. Versatile design and synthesis platform for visualizing genomes with Oligopaint FISH probes. Proc. Natl Acad. Sci. USA 109, 21301–21306 (2012).
Oakley, J. V. et al. Radius measurement via super-resolution microscopy enables the development of a variable radii proximity labeling platform. Proc. Natl Acad. Sci. USA 119, e2203027119 (2022).
Prasanth, K. V. et al. Nuclear organization and dynamics of 7SK RNA in regulating gene expression. Mol. Biol. Cell 21, 4184–4196 (2010).
Fazal, F. M. et al. Atlas of subcellular RNA localization revealed by APEX-seq. Cell 178, 473–490 (2019).
Loda, A., Collombet, S. & Heard, E. Gene regulation in time and space during X-chromosome inactivation. Nat. Rev. Mol. Cell Biol. 23, 231–249 (2022).
Boj, S. F. et al. Organoid models of human and mouse ductal pancreatic cancer. Cell 160, 324–338 (2015).
Course, M. M. et al. Evolution of a human-specific tandem repeat associated with ALS. Am. J. Hum. Genet. 107, 445–460 (2020).
Mattick, J. S. et al. Long non-coding RNAs: definitions, functions, challenges and recommendations. Nat. Rev. Mol. Cell Biol. 24, 430–447 (2023).
Li, J. et al. TMTpro reagents: a set of isobaric labeling mass tags enables simultaneous proteome-wide measurements across 16 samples. Nat. Methods 17, 399–404 (2020).
Andersen, J. S. et al. Directed proteomic analysis of the human nucleolus. Curr. Biol. 12, 1–11 (2002).
Flynn, R. A. et al. 7SK-BAF axis controls pervasive transcription at enhancers. Nat. Struct. Mol. Biol. 23, 231–238 (2016).
UniProt Consortium. UniProt: the universal protein knowledgebase in 2021. Nucleic Acids Res. 49, D480–D489 (2021).
Lingenfelter, P. A. et al. Escape from X inactivation of Smcx is preceded by silencing during mouse development. Nat. Genet. 18, 212–213 (1998).
Chu, C. et al. Systematic discovery of Xist RNA binding proteins. Cell 161, 404–416 (2015).
McHugh, C. A. et al. The Xist lncRNA interacts directly with SHARP to silence transcription through HDAC3. Nature 521, 232–236 (2015).
Minajigi, A. et al. Chromosomes. A comprehensive Xist interactome reveals cohesin repulsion and an RNA-directed chromosome conformation. Science https://doi.org/10.1126/science.aab2276 (2015).
Yu, B. et al. B cell-specific XIST complex enforces X-inactivation and restrains atypical B cells. Cell 184, 1790–1803 (2021).
Disteche, C. M. & Berletch, J. B. X-chromosome inactivation and escape. J. Genet. 94, 591–599 (2015).
Wu, M. et al. lncRNA SLERT controls phase separation of FC/DFCs to facilitate Pol I transcription. Science 373, 547–555 (2021).
Barutcu, A. R. et al. Systematic mapping of nuclear domain-associated transcripts reveals speckles and lamina as hubs of functionally distinct retained introns. Mol. Cell 82, 1035–1052 (2022).
Caudron-Herger, M. et al. Alu element-containing RNAs maintain nucleolar structure and function. EMBO J. 34, 2758–2774 (2015).
Lyon, M. F. X-chromosome inactivation: a repeat hypothesis. Cytogenet. Cell Genet. 80, 133–137 (1998).
Pandey, R. R. et al. Kcnq1ot1 antisense noncoding RNA mediates lineage-specific transcriptional silencing through chromatin-level regulation. Mol. Cell 32, 232–246 (2008).
Simon, M. D. et al. High-resolution Xist binding maps reveal two-step spreading during X-chromosome inactivation. Nature 504, 465–469 (2013).
Engreitz, J. M. et al. The Xist lncRNA exploits three-dimensional genome architecture to spread across the X chromosome. Science 341, 1237973 (2013).
Matheson, T. D. & Kaufman, P. D. Grabbing the genome by the NADs. Chromosoma 125, 361–371 (2016).
van Koningsbruggen, S. et al. High-resolution whole-genome sequencing reveals that specific chromatin domains from most human chromosomes associate with nucleoli. Mol. Biol. Cell 21, 3735–3748 (2010).
Diwakarla, C., Hannan, K., Hein, N. & Yip, D. Advanced pancreatic ductal adenocarcinoma—complexities of treatment and emerging therapeutic options. World J. Gastroenterol. 23, 2276–2285 (2017).
Lomberk, G. et al. Distinct epigenetic landscapes underlie the pathobiology of pancreatic cancer subtypes. Nat. Commun. 9, 1978 (2018).
Jiang, S. et al. A proteomics approach to the cell-surface interactome using the enzyme-mediated activation of radical sources reaction. Proteomics 12, 54–62 (2012).
Rees, J. S., Li, X. W., Perrett, S., Lilley, K. S. & Jackson, A. P. Selective Proteomic Proximity Labeling Assay Using Tyramide (SPPLAT): a quantitative method for the proteomic analysis of localized membrane-bound protein clusters. Curr. Protoc. Protein Sci. 80, 19.27.11–19.27.18 (2015).
Bar, D. Z. et al. Biotinylation by antibody recognition—a method for proximity labeling. Nat. Methods 15, 127–133 (2018).
Dopie, J., Sweredoski, M. J., Moradian, A. & Belmont, A. S. Tyramide signal amplification mass spectrometry (TSA-MS) ratio identifies nuclear speckle proteins. J. Cell Biol. 219, e201910207 (2020).
Cai, Z. et al. RIC-seq for global in situ profiling of RNA-RNA spatial interactions. Nature 582, 432–437 (2020).
Kudla, G., Wan, Y. & Helwak, A. RNA conformation capture by proximity ligation. Annu. Rev. Genomics Hum. Genet. 21, 81–100 (2020).
Dekker, J. & Misteli, T. Long-range chromatin interactions. Cold Spring Harb. Perspect. Biol. 7, a019356 (2015).
Schnell, U., Dijk, F., Sjollema, K. A. & Giepmans, B. N. Immunolabeling artifacts and the need for live-cell imaging. Nat. Methods 9, 152–158 (2012).
Zhou, Y. et al. Metascape provides a biologist-oriented resource for the analysis of systems-level datasets. Nat. Commun. 10, 1523 (2019).
Jain, A. & Vale, R. D. RNA phase transitions in repeat expansion disorders. Nature 546, 243–247 (2017).
Kishi, J. Y. et al. SABER amplifies FISH: enhanced multiplexed imaging of RNA and DNA in cells and tissues. Nat. Methods 16, 533–544 (2019).
Shechner, D. M. & Bartel, D. P. The structural basis of RNA-catalyzed RNA polymerization. Nat. Struct. Mol. Biol. 18, 1036–1042 (2011).
Eng, J. K., Jahan, T. A. & Hoopmann, M. R. Comet: an open-source MS/MS sequence database search tool. Proteomics 13, 22–24 (2013).
Rad, R. et al. Improved monoisotopic mass estimation for deeper proteome coverage. J. Proteome Res. 20, 591–598 (2021).
Schweppe, D. K. et al. Full-featured, real-time database searching platform enables fast and accurate multiplexed quantitative proteomics. J. Proteome Res. 19, 2026–2034 (2020).
Hung, V. et al. Proteomic mapping of the human mitochondrial intermembrane space in live cells via ratiometric APEX tagging. Mol. Cell 55, 332–341 (2014).
Subramanian, A. et al. Gene-set enrichment analysis: a knowledge-based approach for interpreting genome-wide expression profiles. Proc. Natl Acad. Sci. USA 102, 15545–15550 (2005).
Adiconis, X. et al. Comparative analysis of RNA sequencing methods for degraded or low-input samples. Nat. Methods 10, 623–629 (2013).
Kim, D., Paggi, J. M., Park, C., Bennett, C. & Salzberg, S. L. Graph-based genome alignment and genotyping with HISAT2 and HISAT-genotype. Nat. Biotechnol. 37, 907–915 (2019).
Mars, J. C., Sabourin-Felix, M., Tremblay, M. G. & Moss, T. A deconvolution protocol for ChIP-Seq reveals analogous enhancer structures on the mouse and human ribosomal RNA genes. G3 8, 303–314 (2018).
Danecek, P. et al. Twelve years of SAMtools and BCFtools. Gigascience 10, giab008 (2021).
Ramirez, F., Dundar, F., Diehl, S., Gruning, B. A. & Manke, T. deepTools: a flexible platform for exploring deep-sequencing data. Nucleic Acids Res. 42, W187–W191 (2014).
Shumate, A., Wong, B., Pertea, G. & Pertea, M. Improved transcriptome assembly using a hybrid of long and short reads with StringTie. PLoS Comput. Biol. 18, e1009730 (2022).
Love, M. I., Huber, W. & Anders, S. Moderated estimation of fold change and dispersion for RNA-seq data with DESeq2. Genome Biol. 15, 550 (2014).
Jin, Y., Tam, O. H., Paniagua, E. & Hammell, M. TEtranscripts: a package for including transposable elements in differential expression analysis of RNA-seq datasets. Bioinformatics 31, 3593–3599 (2015).
Dobin, A. et al. STAR: ultrafast universal RNA-seq aligner. Bioinformatics 29, 15–21 (2013).
Waskom, M. L. seaborn: statistical data visualization. J. Open Source Softw. 6, 3021 (2021).
Hunter, J. D. Matplotlib: a 2D graphics environment. Comput. Sci. Eng. 9, 90–95 (2007).
Langdon, W. B. Performance of genetic programming optimised Bowtie2 on genome comparison and analytic testing (GCAT) benchmarks. BioData Min 8, 1 (2015).
Lund, E., Oldenburg, A. R. & Collas, P. Enriched domain detector: a program for detection of wide genomic enrichment domains robust against local variations. Nucleic Acids Res. 42, e92 (2014).
Stovner, E. B. & Saetrom, P. epic2 efficiently finds diffuse domains in ChIP-seq data. Bioinformatics 35, 4392–4393 (2019).
Quinlan, A. R. & Hall, I. M. BEDTools: a flexible suite of utilities for comparing genomic features. Bioinformatics 26, 841–842 (2010).
Zhang, Y. et al. Model-based analysis of ChIP-seq (MACS). Genome Biol. 9, R137 (2008).
Ernst, J. & Kellis, M. ChromHMM: automating chromatin-state discovery and characterization. Nat. Methods 9, 215–216 (2012).
Bonora, G. et al. Orientation-dependent Dxz4 contacts shape the 3D structure of the inactive X chromosome. Nat. Commun. 9, 1445 (2018).
Schindelin, J. et al. Fiji: an open-source platform for biological-image analysis. Nat. Methods 9, 676–682 (2012).
Rueden, C. T. et al. ImageJ2: ImageJ for the next generation of scientific image data. BMC Bioinformatics 18, 529 (2017).
Gilles, J. F., Dos Santos, M., Boudier, T., Bolte, S. & Heck, N. DiAna, an ImageJ tool for object-based 3D co-localization and distance analysis. Methods 115, 55–64 (2017).
Uhlen, M. et al. Towards a knowledge-based Human Protein Atlas. Nat. Biotechnol. 28, 1248–1250 (2010).
Mouse Genome Database (MGD) at the Mouse Genome Informatics website. http://www.informatics.jax.org (2023).
Acknowledgements
We thank J. Gianopulos, C. Hsu, C. Anderson, H. Gizinski, C. Lin and J. Cabarrus for general technical assistance; Y. Sancak, A. Jain, M. Das, R. Akilesh, P. Valdmanis, J. Scott and S. Smukowski for the kind donation of materials; T. Moss for rRNA computational tools; N. Peters, K. Collins, M. Soruco, E. Hacisüleyman and A. Fenix for imaging assistance; A. Bertero, S. Attar and E. Nichols for help with cell-based models; H. -T. Lau and M. G. Golkowski for MS assistance; G. Yardimci, G. Bonara, A. Mishra, R.D. Hawkins and W. Noble for sequencing assistance; and members of the laboratories of D.M.S., Y. Sancak and R. Gardner for thoughtful discussions and critiques. This work was supported by National Institutes of Health (NIH) grants 1R01GM138799-01 and 1R01HL160825-01 (to D.M.S., A.F.T. and E.E.K.), 1R35GM137916 (to B.J.B. and E.H.), 1R35GM150919-01 (to. D.K.S. and R.F.), R01GM129090 (to S.-E.O. and D.M.M.), UM1HG011586 and GM131745 (to X.D. and C.M.D.), R37CA241472 (to S.K.), T32GM007750 (to A.F.T. and E.E.K.) and T32HG000035 (to C.D.M.), a Safeway Albertsons Early Career Award in Cancer Research (to D.M.S.), the UW Royalty Research Fund (to D.M.S.), a Brotman Baty Institute Catalytic Collaborations Award (to D.M.S. and S.K.) and the UW Student Technology Fund. E.E.K. was supported by the NSF DEB2016186 and the AHA 902616. Imaging at the UW Keck Center was supported by NIH S10 OD016240 and the UW Student Technology Fee. This work used an EASY-nLC 1200 UHPLC and Thermo Scientific Orbitrap Fusion Lumos Tribrid mass spectrometer purchased with funding from NIH grant S10OD021502 (to S.-E.O. and D.M.M.). Next-generation sequencing data analysis was facilitated through the use of advanced computational, storage and networking infrastructure provided by the Hyak supercomputer system and funded by the STF at the UW.
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Contributions
A.F.T., E.E.K. and D.M.S. conceived of, designed and analyzed all experiments, which were principally performed by A.F.T and E.E.K., and assisted by D.Q.L. and M.K. MS analysis was performed by R.F., C.D.M., D.M.M., S.-E.O. and D.K.S. S.K. assisted with PDA and organoid experiments. X.D. and C.M.D. assisted with all Xist- and Firre-related experiments. B.J.B. and E.A.H. assisted with oligonucleotide probe design. D.M.S. directed research. All authors contributed to writing.
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A.F.T., E.E.K., B.J.B. and D.M.S. have filed for a patent concerning the use of oligonucleotide-directed proximity labeling to elucidate and visualize subcellular interactions in situ. D.Q.L., R.F., C.D.M., D.M.M., E.H., X.D., M.K., S.-E.O., C.M.D. and S.K. declare no competing interests.
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Nature Methods thanks Gene Yeo, Hsueh-Ping Chu, Piero Carninci and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Primary Handling Editor: Rita Strack, in collaboration with the Nature Methods team.
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Extended data
Extended Data Fig. 1 Alternative O-MAP designs.
a, summary of RNA-targeted HRP-recruitment strategies tested. Design 1 uses biotinylated primary probes to recruit a streptavidin-HRP conjugate. Designs 2 and 3 use Digoxigenin (DIG)-labeled primary or secondary probes to recruit an HRP–conjugated anti-DIG antibody. Our final O-MAP design, which uses HRP-conjugated oligo probes, is shown for comparison (see also, Fig. 1a). The same anti-DIG antibody is used in designs 2 and 3; the same “universal landing pad” sequences are used in designs 3 and 4. b–e, limitations of Designs 1–3. In all cases biotin was visualized by staining with a fluorescent neutravidin conjugate. b, Design 1 was disfavored because in situ biotinylation cannot be distinguished from biotinylated probes. HeLa cells over-expressing NPM1~eGFP were probed using the same 47S-targeting probes as in (Supplementary Fig. 1), bearing 3´–terminal biotin. c, Design 2—analogous to HyPro—in HeLa cells. This sometimes produced well-resolved nucleolar-targeted biotinylation, but was disfavored due to antibody irreproducibility (see below). The high cost of DIG-labeled oligos would also limit its use with low-abundance transcripts, which can require dozens-to-hundreds of probes. d, Design 3 overcomes the oligo cost issue but still suffers from antibody background binding and irreproducibility. HeLa cells were probed with the same 47S-targeting primary probe set and DIG-labeled secondary oligo, using four different lots of commercial HRP-conjugated antibodies. In some cases, we observed well-resolved RNA-targeted biotinylation (panel i), though other lots from the same vendor exhibited significant off-target labeling (panel ii, arrows). Regents from other vendors exhibited varying degrees of blurring (panel iii), or excessive off-target biotinylation (panel iv). e, Design 3 is particularly problematic with lower-abundance RNA targets. Patski cells were probed with the same Xist-targeting, landing-pad-extended probes as used in the main text, divided into two sub-pools. Anti-DIG-HRP was from Vendor 1. Note that all conditions—both probe sub-pools and the omit-primary negative control–induced substantial off-target biotinylation. All scale bars, 20 µm.
Extended Data Fig. 2 More O-MAP controls and imaging analysis.
a, O-MAP and negative control experiments were performed in HeLa cells, as indicated. Biotin was imaged using a fluorescent neutravidin conjugate; NPM1 via immunofluorescence. Note that omitting any component of the O-MAP pipeline ablated biotinylation signal. The 47S-O-MAP, 7SK-O-MAP, omit primary and scrambled primary conditions (left four columns) are the same images presented in (Fig. 1b). Scale bars, 20 µm. b, Representative line traces of each condition. Note the overlap in NPM1 and O-MAP signals in the 47S O-MAP condition; the lack of overlap in 7SK O-MAP, and the nearly complete absence of biotinylation under all other conditions. Scale bars, 10 µm. The 47S O-MAP image are the same data presented in (Fig. 1b). In all “omit-H2O2” conditions (marked *), cells were pre-quenched with sodium azide and ascorbic acid prior to the addition of biotin-phenol and H2O2. Simply removing H2O2 from the O-MAP protocol still resulted in targeted in situ biotinylation (that is nucleolar labeling using 47S probes), presumably due to photoactivation by HRP.
Extended Data Fig. 3 O-MAP is more spatially precise than genetically encoded proximity-labeling systems.
a, Qualitative assessment of off-target biotinylation by 47S-targeted O-MAP (left) and nucleolar-targeted APEX2 ~ GFP (right). NPM1 was visualized by immunofluorescence; APEX2 ~ GFP by autofluorescence. O-MAP data are the same as presented in (Fig. 1b and Extended Data Fig. 1); APEX2 data are the same as in (Fig. 1c). Note prominent nucleoplasmic (off-target) labeling by APEX2, indicated by arrowheads. Scale bars, 10 µm. b, More head-to-head comparisons between 47S O-MAP and APEX2~NoLS, quantified in line-traces. Green: APEX2 ~ GFP biotinylation; Purple: 47S O-MAP biotinylation. Scale bars: 10 µm. c, Quantifying 47S O-MAP background biotinylation. Left: DAPI signal was used to identify Regions of Interest (ROI; yellow outlines), corresponding to individual nuclei, and the biotinylation intensities for all pixels within each ROI were measured. Right: histogram summarizing the distribution of biotinylation intensities observed within Cell 1. Note the prominent peak near zero, indicating that most pixels contained little or no signal. Inset highlights a minor peak of intense biotinylation (>17,500). d, The same approach was applied to APEX2~NoLS cells. Left: ROIs defined; Right: Histogram of observed biotinylation intensities within cell 1. Note the lower proportion of pixels near zero, fewer pixels at high signal intensities (inset) and the prominent peak between 1500–3600—suggesting significant background labeling. In c, d, a single z-slice is shown; scale bars, 20 µm. e, Cumulative distribution functions of biotinylation intensities for O-MAP and APEX2~NoLS (n = 4). Mean values over all ROIs (dark lines). Lighter bands correspond to the maximum and minimum values observed. Larger plot highlights the distributions at intensities below 10,000; inset shows all data. 59% of pixels in the O-MAP experiment were below 1000; only 14% of APEX2 pixels fell within this range, suggesting that O-MAP’s lower background biotinylation. Furthermore, 57% of APEX2 pixels fell between 1500—3600, while only 8% of O-MAP data fall in this range. All images under direct comparison (for example, all images in a; all in b; and the images in c and d) were collected on the same day, using the same acquisition parameters.
Extended Data Fig. 4 Probing the nucleolar proteome with 47S O-MAP-MS.
a, Receiving-Operator Characteristic (ROC) analysis of the 47S vs 7SK O-MAP-MS experiment. True Positive and False Positive proteins were defined using lists of exclusively nucleolar and exclusively nucleoplasmic proteins, respectively, as reported by the Human Protein Atlas (HPA). An Area Under the Curve (AUC) of nearly 1.0 suggests strong and highly sensitive selectivity for nucleolar proteins over the nucleoplasmic proteome. b, These data were used to derive an optimal Log2(fold change, 47S/7SK) cutoff value of 0.523, and to define a putative list of 258 O-MAP core nucleolar proteins, as described in (Fig. 3). c–e, Parallel analysis using (47S/Scramble controls), instead of (47S/7SK). c, Volcano plot and histograms of showing the enrichment of HPA-nucleolar, HPA-Nucleoplasmic, and HPA-bilocalized proteins, using the same protein marker reference lists as in (a, b), and (Fig. 3c, d). Benjamini Hochberg corrected p-values (FDR). d, ROC analysis of the (47S/Scramble) data demonstrates slightly lower sensitivity than that of the (47S/7SK) analysis, though still exceptionally. e, As in (b), these data were used to determine an optimal Log2(fold change, 47S/Scramble) cutoff value of 2.201, defining a putative cohort of 286 O-MAP core nucleolar proteins. f, The putative nucleolar proteomes derived from the (47S/7SK) and (47S/Scramble) ROC analyses show considerable overlap (66–73%). Outliers were used for Gene Ontology (GO)-term analysis. Factors uniquely captured by the (47S/7SK) analysis were highly enriched for ribosome biogenesis factors, while those unique to the (47S/Scramble) analysis were enriched for nucleoplasmic functions. This suggests that the (47S/7SK) comparison more precisely captures the nucleolar proteome. Hypergeometric test with Benjamini-Hochberg correction.
Extended Data Fig. 5 Coverage of the nucleolar proteome during the 47S O-MAP labeling time course.
a, Volcano plots for each 47S O-MAP labeling point, calculated relative to the 7SK/10-min label condition. Enrichment of nucleolar proteins derived from our k-medoid analysis (Fig. 3h–j; Supplementary Fig. 10) are highlighted in pink. Significance cutoffs were assigned at padj ≤ 0.05 and Fold Change (47S/7SK) ≥ 2.0. (dotted lines). Benjamini Hochberg corrected p-values (FDR) b, Table summarizing the recovery of the nucleolar proteome at each labeling time point. Note that coverage appears to plateau at 10 min.
Extended Data Fig. 6 Comparison of 47S-targeted O-MAP-MS and HyPro-MS.
Top: Venn diagram of enriched proteins from 47S-targeted HyPro-MS (gray) and the k-medoid-derived high-confidence O-MAP nucleolar proteome (Fig. 3j; Supplementary Table 3). Note that O-MAP enriches more than 50% of the HyPro nucleolar proteome. Bottom: Gene Ontology analysis of the outlier proteins observed by HyPro-MS (101 proteins; left) and by O-MAP-MS (194 proteins, right). The top 10 most highly enriched terms are shown. Note that the O-MAP-MS outliers are predominantly nucleolar proteins and ribosome biogenesis factors, suggesting that HyPro has undersampled the nucleolar proteome. In contrast, HyPro outliers exhibit little association with the nucleolus or its central functions, suggesting that they may be noise. Hypergeometric test with Benjamini-Hochberg correction.
Extended Data Fig. 7 Probing the Xi compartment with O-MAP-MS.
a, Receiving-Operator Characteristic (ROC) analysis of the Xist O-MAP-MS experiment. True Positives (183 proteins; Supplementary Table 2) were defined as Xist-interacting proteins observed previously via antisense oligonucleotide purification methods. False Positives (104 proteins; Supplementary Table 2) were defined using the Jackson Laboratory Mouse Genome Informatics portal (JAX MGI; https://www.informatics.jax.org/vocab/gene_ontology) list of tRNA modifying factors, manually curated to remove duplicate entries and factors that lack nuclear localization. An Area Under the Curve (AUC) of 0.92 suggests strong and highly sensitive selectivity for known Xist interactors relative to the broader proteome. b, These data were used to derive an optimal Log2(fold change, Xist/mock) cutoff value of 0.916, and to define a putative list of 621 O-MAP Xi-proximal proteins, as described in (Fig. 4). c, Behavior of other prominent gene sets in the Xist O-MAP experiment, based on their subnuclear localization (top) or molecular function (bottom). All sets were defined using JAX MGI, manually curated to remove duplicate entries and factors in our Xist True Positive list. None of these gene sets is more highly enriched than known Xist interactors en toto (Fig. 4c). However, each set contains a subset of factors that are enriched by Xist O-MAP-MS, suggesting a functional role for these factors within the Xi compartment. Student’s two-tailed T-Test, with a permutation-based FDR adjustment.
Extended Data Fig. 8 47S O-MAP-Seq enriches known and novel nucleolar transcripts.
a, the 47S pre-rRNA. Note prominent enrichment for the 5´–ETS, IT1, and ITS2 “transcribed spacer” domains. Sequences corresponding to the mature 18S, 5.8S, and 28S rRNAs are removed during sequencing library preparation. Reads are aligned to a custom genome assembly containing a single copy of the rDNA consensus sequence (courtesy of T. Moss, U. Laval) annotated as a unique chromosome. b, the U3 noncoding RNA, which directs key cleavage events during ribosomal biogenesis, c, d, exemplar Box C/D (c) and H/ACA (d) small nucleolar RNAs (snoRNAs). SnoRNAs are often expressed within the introns of protein-coding genes (gray). e, RNase MRP (enriched) upstream of the CCDC107 gene (not enriched). f, lncRNA SLERT, which is processed from the two H/ACA snoRNAs embedded in the TBRG4 gene. g, Example of a novel nucleolar transcript—a processed pseudogene—discovered by O-MAP-Seq.
Extended Data Fig. 9 Comparison of 47S O-MAP-Seq and HyPro-Seq.
a, Heatmap of Pearson correlations, comparing three biological replicates of 47S O-MAP-Seq and two biological replicates (four technical replicates each) of the analogous HyPro-Seq experiment. Comparisons were made between log2(fold change, enriched/input) for each replicate. Note the high inter-replicate reproducibility of O-MAP (r = 0.87–0.93), and that its correlation to HyPro-Seq Replicate A (r = 0.53–0.58) is comparable to the correlation between HyPro-Seq biological replicates (r = 0.55–0.56). b, Example scatter plots of the data used in (a), highlighting O-MAP-Seq’s superior reproducibility. c, O-MAP-Seq and HyPro-Seq enrich many of the same transcripts. Volcano plot of 47S O-MAP-Seq data, equivalent to (Fig. 5b), with coding and noncoding isoforms merged. 47S O-MAP-Seq prominently enriches many of the transcripts that were enriched by 47S HyPro-Seq (red), in addition to a smaller set of unique RNAs (blue). Note that relatively few of the transcripts that were uniquely enriched by HyPro-Seq (dark gray) were de-enriched by O-MAP; the majority of these RNAs fell below the significance cutoff of detection, presumably due to the O-MAP-Seq dataset’s lower sequencing depth. Significance testing: Wald’s test. d, Breakdown of 47S-proximal RNAs by transcript class, for those enriched by O-MAP-Seq (blue), HyPro-Seq (gray), and both methods (red). Although the overall composition is similar, HyPro-Seq enriches more protein coding genes and mitochondrial tRNAs, which are not thought to be nucleolar, and fewer lncRNAs and pseudogenic transcripts. e, Isoform-level analysis of enriched transcripts arising from protein-coding genes, analogous to (Fig. 5d). Note that HyPro-Seq enriches a higher proportion of protein-coding isoforms, and lower proportion of retained intron-containing transcripts. Collectively, these data suggest that O-MAP-Seq largely recapitulates the data obtained by analogous methods, but with lower noise and higher reproducibility.
Extended Data Fig. 10 Xist O-MAP-Seq enriches nascent transcripts of XCI-escape genes.
a, Enrichment of the Xist gene itself. Note different scales for input RNA and O-MAP-Seq tracks. The lack of intronic reads suggests that O-MAP-Seq has predominantly targeted and captured the mature Xist transcript. The absence of reads mapping to the antisense noncoding RNA TsiX, a lncRNA that is monoallelically expressed from the Xa (gray), confirms that O-MAP-Seq is precisely labeling the Xi. b, Enriched XCI-escape genes appear to be nascent transcripts. In all cases, read densities for both Input RNA (gray) and O-MAP-Seq (red) are shown, using matched scales. Note prominent intronic read density for all XCI-escape genes (Shroom4, Pbdc1, Magee1, Mid1, Erdr1). Transcript structures denoting the most prominent isoforms are displayed; other nearby genes not known to escape XCI are denoted in gray. c, Xist O-MAP-Seq does not appear to preferentially capture nascent transcripts of non-XCI-escape genes. Two examples (Tspan6 and Rps4x) are shown, neither of which was enriched by Xist O-MAP-Seq. Note the absence of prominent intronic read density, suggesting that the intronic signatures observed in (b) are not general artifacts of the O-MAP-Seq pipeline.
Supplementary information
Supplementary Information
Supplementary Discussion, References and Figs. 1–13; Source Data for Supplementary Fig. 4.
Supplementary Data 1
Source microscopy images for Supplementary Fig. 1.
Supplementary Data 2
Source microscopy images for Supplementary Fig. 2.
Supplementary Data 3
Source microscopy images for Supplementary Fig. 3.
Supplementary Data 4
Source microscopy images for Supplementary Fig. 4.
Supplementary Data 5
Source microscopy images for Supplementary Fig. 5.
Supplementary Data 6
Statistical source data for Supplementary Fig. 8.
Supplementary Tables
Supplementary Tables 1–5.
Source data
Source Data Fig. 1
Source microscopy and blotting images for Fig. 1. Contains 24 imaging files, and two uncropped gel images.
Source Data Fig. 2
Source microscopy images for Fig. 2. Contains 62 imaging files.
Source Data Fig. 3
Source microscopy images and statistical source data for Fig. 3. Imaging archive contains eight imaging files. Source data archive contains five statistical source data files, for 3b,c,e,f.
Source Data Fig. 3
Source microscopy images and statistical source data for Fig. 3. Imaging archive contains eight imaging files. Source data archive contains five statistical source data files, for 3b,c,e,f.
Source Data Fig. 4
Source statistical data for Fig. 4b,d,e.
Source Data Fig. 5
Source microscopy images and statistical source data for Fig. 5. Imaging archive contains nine images. Source data archive contains seven statistical source data files, for 5b,c,f,h.
Source Data Fig. 5
Source microscopy images and statistical source data for Fig. 5. Imaging archive contains nine images. Source data archive contains seven statistical source data files, for 5b,c,f,h.
Source Data Fig. 6
Statistical source data for 6c,g,i.
Source Data Extended Data Fig. 1
Source microscopy images for Extended Data Fig. 1. Contains 21 images.
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Source microscopy images for Extended Data Fig. 2. Contains 20 images.
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Source microscopy images and statistical source data for Extended Data Fig. 3. Imaging archive contains 9 images. Statistical source data contains three data files.
Source Data Extended Data Fig. 3
Source microscopy images and statistical source data for Extended Data Fig. 3. Imaging archive contains 9 images. Statistical source data contains three data files.
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Statistical source data for Extended Data Fig. 4. Contains four data files.
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Statistical source data for Extended Data Fig. 5.
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Statistical source data for Extended Data Fig. 6. Contains two files.
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Statistical source data for Extended Data Fig. 7. Contains two files.
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Statistical source data for Extended Data Fig. 9c–e. Contains three files.
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Tsue, A.F., Kania, E.E., Lei, D.Q. et al. Multiomic characterization of RNA microenvironments by oligonucleotide-mediated proximity-interactome mapping. Nat Methods 21, 2058–2071 (2024). https://doi.org/10.1038/s41592-024-02457-6
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DOI: https://doi.org/10.1038/s41592-024-02457-6
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