蛋白质互作,你看得到.

2023-05-10 14:56:27

转录因子蛋白互作并形成复合体调控基因表达是生物体内无时无刻都在发生的生物学过程。利用现代生物技术手段，蛋白间的互作模式、复合体的构成以及调控基因表达的方式正在逐渐被科学家一一破解。然而，我们很难通过直观的手段看到这一过程。FRET-FLIM（Förster resonance energy transfer measured by fluorescence lifetime microscopy）是用荧光寿命成像的手段测定共振能量转移的技术。FRET-FLIM因其受干扰因素少的优势，已经成为研究活细胞中生物大分子构象变化和分子间动态相互作用的常用技术。最新一期的《Nature》杂志报道了科学家利用体内FRET-FLIM技术揭示了拟南芥根中细胞特异性蛋白间的互作方式。

拟南芥根尖维管束四周的U型区可以分为不活动区、内皮层和皮层内皮层起始区几个部分，每个区域的细胞形态迥然不同。这三个区域的基因受到SHR、SCR、JKD等转录因子的调控。研究人员利用FRET-FLIM技术，在活体根尖细胞内观察到SHR、SCR、JKD三个转录因子的互作模式在不同的区域内有所差异。不同的作用方式导致了复合体呈现出不同的构象，从而调控不同的靶标基因，形成不同的细胞状态。

该研究利用FRET-FLIM技术在植物中实现了蛋白互作的可视化，也更深入地揭示了根尖细胞发育的分子机理。

Nature. 2017 Jul 26.

In vivo FRET-FLIM reveals cell-type-specific protein interactions in Arabidopsis roots.

Author

Long Y, Stahl Y, Weidtkamp-Peters S……Simon R, Scheres B, Blilou I*.

*: Plant Developmental Biology, Wageningen University and Research Centre; Molecular Genetics, Department Biology, Utrecht University, The Netherlands.

Abstract

During multicellular development, specification of distinct cell fates is often regulated by the same transcription factors operating differently in distinct cis-regulatory modules, either through different protein complexes, conformational modification of protein complexes, or combinations of both. Direct visualization of different transcription factor complex states guiding specific gene expression programs has been challenging. Here we use in vivo FRET-FLIM (Förster resonance energy transfer measured by fluorescence lifetime microscopy) to reveal spatial partitioning of protein interactions in relation to specification of cell fate. We show that, in Arabidopsis roots, three fully functional fluorescently tagged cell fate regulators establish cell-type-specific interactions at endogenous expression levels and can form higher order complexes. We reveal that cell-type-specific in vivo FRET-FLIM distributions reflect conformational changes of these complexes to differentially regulate target genes and specify distinct cell fates.

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