Project description:In eukaryotic cells, the precise spatial localization of RNAs and proteins is essential for proper cellular function. Genetically encoded photocatalytic proximity labeling techniques have expanded our ability to map subcellular proteomes and transcriptomes, but their temporal resolution remains limited. Here, we introduce Lantern, an engineered flavoprotein optimized via directed evolution, which enables sub‑minute, spatially resolved labeling of cellular biomolecules. Lantern is targetable to diverse subcellular compartments, including the endoplasmic reticulum, mitochondria, and stress granules (SGs), to map local transcriptomes (CAP-seq) and proteomes (CAP-MS). Using Lantern, we observed that m6A‑enriched RNAs are recruited to SGs within five minutes of stress induction, while ER‑proximal RNAs associate with the SG scaffold protein G3BP1 during early SG assembly. Additionally, Lantern was adapted for cell-surface tagging (CAP-CELL), enabling spatially resolved cell typing and the analysis of cell-cell interactions. Collectively, this study establishes Lantern as a powerful tool that offers unprecedented temporal resolution for investigating the dynamic organization of subcellular molecular networks.
Project description:Subcellular organization of RNAs and proteins is critical for cell function, but we still lack global maps and conceptual frameworks for how these molecules are localized in cells and tissues. Here we introduce ATLAS-Seq, which generates transcriptomes and proteomes from detergent-free tissue lysates fractionated across a sucrose gradient. Proteomic analysis of fractions confirmed separation of subcellular compartments. Unexpectedly, RNAs tended to co-sediment with other RNAs in similar protein complexes, cellular compartments, or biological functions. With the exception of those encoding secreted proteins, most RNAs sedimented differently than their encoded protein counterparts. To identify RNA binding proteins potentially driving these patterns, we correlated their sedimentation profiles to all RNAs, confirming known interactions and predicting new associations. Hundreds of alternative RNA isoforms exhibited distinct sedimentation patterns across the gradient, despite sharing most of their coding sequence. These observations suggest that transcriptomes can be organized into networks of co-segregating mRNAs encoding functionally related proteins, and provide insights into the establishment and maintenance of subcellular organization.
Project description:We used state of the art mass spectrometry (MS) and RNA sequencing (RNA-Seq) to provide the first integrated proteomic, phosphoproteomic and transcriptomic atlas of the animal model Mus musculu . We measured 66 murine pancreatic ductal adenocarcinoma cell lines (66 proteomes and 66 phosphoproteome) and 41 healthy tissues (41 proteomes, 41 phosphoproteome, and 29 transcriptomes). The employed MS-based and bioinformatics strategy identified >17,000 proteins and >50,000 phosphorylation sites, providing expression evidence for ~76% of the 22,437 protein-coding genes reported in UniProtKB. The RNA-Seq strategy resulted in the quantification of 21,261 unique gene that were expressed in at least one of the 29 sequenced tissue.
