A subcellular map of translational machinery composition and regulation at the single-molecule level

• 成果类型: Article
• 署名作者: Zhang, Zijian; Xu, Adele; Bai, Yunhao; Chen, Yuxiang; Cates, Kitra; Kerr, Craig; Bermudez, Abel; Susanto, Teodorus Theo; Wysong, Kelsie; Garcia Marques, Fernando J.; Nolan, Garry P.; Pitteri, Sharon; Barna, Maria
• 署名单位: Stanford University; Stanford University; Stanford University; Stanford University; Stanford University
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-10914
• DOI: 10.1126/science.adn2623
• 发表日期: 2025-03-07
• 关键词: endoplasmic-reticulum stress; tail-anchored proteins; expansion microscopy; messenger-rnas; in-vivo; ribosome; DYNAMICS; initiation; cells; translocation

摘要

Millions of ribosomes are packed within mammalian cells, yet we lack tools to visualize them in toto and characterize their subcellular composition. In this study, we present ribosome expansion microscopy (RiboExM) to visualize individual ribosomes and an optogenetic proximity-labeling technique (ALIBi) to probe their composition. We generated a super-resolution ribosomal map, revealing subcellular translational hotspots and enrichment of 60S subunits near polysomes at the endoplasmic reticulum (ER). We found that Lsg1 tethers 60S to the ER and regulates translation of select proteins. Additionally, we discovered ribosome heterogeneity at mitochondria guiding translation of metabolism-related transcripts. Lastly, we visualized ribosomes in neurons, revealing a dynamic switch between monosomes and polysomes in neuronal translation. Together, these approaches enable exploration of ribosomal localization and composition at unprecedented resolution.