Downie Laura, Ferrandiz Nuria, Courthold Elizabeth, Jones Megan, Royle Stephen J
Centre for Mechanochemical Cell Biology, Warwick Medical School, University of Warwick, Coventry, United Kingdom.
PLoS Biol. 2025 Jul 10;23(7):e3003249. doi: 10.1371/journal.pbio.3003249. eCollection 2025 Jul.
Membrane contact sites (MCSs) are areas of close proximity between organelles that allow the exchange of material, among other roles. The endoplasmic reticulum (ER) has MCSs with a variety of organelles in the cell. MCSs are dynamic, responding to changes in cell state, and are, therefore, best visualized through inducible labeling methods. However, existing methods typically distort ER-MCSs, by expanding contacts or creating artificial ones. Here, we describe a new method for inducible labeling of ER-MCSs using the Lamin B receptor (LBR) and a generic anchor protein on the partner organelle. Termed LaBeRling, this versatile, one-to-many approach allows labeling of different types of ER-MCSs (mitochondria, plasma membrane, lysosomes, early endosomes, lipid droplets, and Golgi), on-demand, in interphase or mitotic human cells. LaBeRling is nondisruptive and does not change ER-MCSs in terms of the contact number, extent or distance measured; as determined by light microscopy or a deep-learning volume electron microscopy approach. We applied this method to study the changes in ER-MCSs during mitosis and to label novel ER-Golgi contact sites at different mitotic stages in live cells.
膜接触位点(MCSs)是细胞器之间紧密相邻的区域,除了其他作用外,还允许物质交换。内质网(ER)与细胞中的多种细胞器存在膜接触位点。膜接触位点是动态的,会对细胞状态的变化做出反应,因此,通过诱导标记方法进行可视化观察最为合适。然而,现有的方法通常会通过扩大接触或产生人工接触来扭曲内质网-膜接触位点。在此,我们描述了一种利用核纤层蛋白B受体(LBR)和伴侣细胞器上的通用锚定蛋白对内质网-膜接触位点进行诱导标记的新方法。这种方法称为LaBeRling,是一种通用的、一对多的方法,能够在间期或有丝分裂的人类细胞中按需标记不同类型的内质网-膜接触位点(线粒体、质膜、溶酶体、早期内体、脂滴和高尔基体)。LaBeRling不会造成破坏,并且在接触数量、范围或测量距离方面不会改变内质网-膜接触位点;这是通过光学显微镜或深度学习体积电子显微镜方法确定的。我们应用该方法研究有丝分裂期间内质网-膜接触位点的变化,并在活细胞的不同有丝分裂阶段标记新的内质网-高尔基体接触位点。