Genetically encoded X-ray cellular imaging for nanoscale protein localization

• 作者: Chunhai Fan Huating Kong Hyun-Joon Shin Jian Wang Jiang Li Jichao Zhang Jun Hu Kai Xia Lihua Wang Qinglong Yan Renzhong Tai Ying Zhu
• 来源期刊: 国家科学评论（英文版）
• 关键词: synchrotron-based X-ray microscopy cellular imaging nanoscale protein localization genetically encoded X-ray tags 3,3'-diaminobenzidine polymers
• 年，卷（期）: 2020,（7）
• 页码范围: 1218-1227
• 页数: 10页
• 语种: 英文
• DOI: 10.1093/nsr/nwaa055

摘要

Spatial resolution defines the physical limit of microscopes for probing biomolecular localization and interactions in cells.Whereas synchrotron-based X-ray microscopy (XRM) represents a unique approach for imaging a whole cell with nanoscale resolution due to its intrinsic nanoscale resolution and great penetration ability,existing approaches to label biomolecules rely on the use of exogenous tags that are multi-step and error-prone.Here,we repurpose engineered peroxidases as genetically encoded X-ray-sensitive tags (GXET) for site-specific labeling of protein-of-interest in mammalian cells.We find that 3,3'-diaminobenzidine (DAB) polymers that are in-situ catalytically formed by fusion-expressed peroxidases are visible under XRM.Using this new tag,we imaged the protein location associated with the alteration of a DNA-methylation pathway with an ultra-high resolution of 30 nanometers.Importantly,the excellent energy resolution of XRM enables multicolor imaging using different peroxidase tags.The development of GXET enlightens the way to nanoscopic imaging for biological studies.