波士顿大学John T. Ngo研究组宣布他们开发出RNA稳定的外壳蛋白，用于活细胞中不同单一mRNAs的敏感和同时成像。该研究于2025年9月22日发表于国际一流学术期刊《自然—方法学》杂志上。

在这里，该研究团队介绍了MS2和PP7外壳蛋白（该研究团队命名为dMCP和dPCP）的条件稳定变体，旨在降低活细胞RNA成像的背景。利用结合环状排列和降解掩蔽的蛋白质工程方法，研究组生成了dMCP和dPCP变体，除了与同源RNA配体结合外，它们可以快速降解。这些增强使单个mRNA分子在活细胞的不同亚室中受到差异调节的敏感可视化成为可能。该团队进一步展示了MS2和PP7基序正交的双色成像，允许在同一细胞内同时低背景可视化不同的RNA物种。总的来说，这项工作为RNA成像提供了通用的低背景探针，这将在含有MS2和PP7的RNA的成像和生物技术利用中具有广泛的用途。

据了解，RNA定位和调控对细胞功能至关重要，但由于未结合探针的背景辐射，许多活RNA成像工具的灵敏度有限。

附：英文原文

Title: RNA-stabilized coat proteins for sensitive and simultaneous imaging of distinct single mRNAs in live cells

Author: Kuffner, Christopher J., Marzilli, Alexander M., Ngo, John T.

Issue&Volume: 2025-09-22

Abstract: RNA localization and regulation are critical for cellular function, yet many live RNA imaging tools suffer from limited sensitivity due to background emissions from unbound probes. Here we introduce conditionally stable variants of MS2 and PP7 coat proteins (which we name dMCP and dPCP) designed to decrease background in live-cell RNA imaging. Using a protein engineering approach that combines circular permutation and degron masking, we generated dMCP and dPCP variants that rapidly degrade except when bound to cognate RNA ligands. These enhancements enabled the sensitive visualization of single mRNA molecules undergoing differential regulation within various subcompartments of live cells. We further demonstrate dual-color imaging with orthogonal MS2 and PP7 motifs, allowing simultaneous low-background visualization of distinct RNA species within the same cell. Overall, this work provides versatile, low-background probes for RNA imaging, which should have broad utility in the imaging and biotechnological utilization of MS2-containing and PP7-containing RNAs.

DOI: 10.1038/s41592-025-02782-4

Source: https://www.nature.com/articles/s41592-025-02782-4