Regulation and functional effects of localized RNAs

在过去的一年里，我们提供了一个详细的分子解释，即特定mrna如何靶向突起有助于有效的细胞迁移和侵袭。具体来说，我们已经证明了蛋白质合成的确切亚细胞位点，以及新生链外观的动力学，作为一种“伴侣选择”机制，指定结合伴侣，从而确定新合成蛋白质的功能潜力。这项研究已经在BioRxiv上发表，目前正在分子细胞杂志上出版（Gasparski et al, Mol. Cell，出版中）。本研究通过揭示一种调节蛋白质复合物形成和多种相互作用伙伴选择的机制，提供了重要的概念进展。它进一步提供了一个解释，并定义了一个新的框架，以理解即使在小的、动态的细胞中也需要精确的mRNA区隔化和靶向。此外，我们还描述了一种实验方法，用于可视化和定量mRNA定位在三维癌球体的侵袭性前端。这项工作作为一章发表在《分子生物学方法》系列书《三维细胞迁移》（Moissoglu et al., Methods Mol Biol, 2023）。它提出了一种在三维图像中识别RNA点的方法，并量身定制用于定量描述和比较表现出前后极化的细胞背景下的分布。对侵袭性先导癌细胞前细胞质的mRNA分布进行了分析流水线。然而，它可以适用于各种其他设置的前后偏振或更广泛的情况下的偏振沿线性轴。该分析还可以应用于其他细胞类型或RNA成像方法，具有广泛的潜在适用性。

In the past year, we have provided a detailed molecular explanation of how targeting of specific mRNAs to protrusions contributes to efficient cell migration and invasion. Specifically, we have shown that the exact subcellular site of protein synthesis, as well as the kinetics of appearance of nascent chains, function as a 'partner-selection' mechanism that specify the binding partners and consequently the functional potential of newly-synthesized proteins. This study has been reported in BioRxiv and is currently in press in the journal Molecular Cell (Gasparski et al, Mol. Cell, in press). This study has provided an important conceptual advance through revealing a mechanism that can regulate the formation of protein complexes and the choice among multiple interacting partners. It has further provided an explanation and defined a new framework for understanding the need for precise mRNA compartmentalization and targeting even in small, dynamic cells. We have additionally described an experimental methodology for visualizing and quantifying mRNA localization at the invasive front of 3D cancer spheroids. This work was published as a chapter in a Methods in Molecular Biology book series on Cell Migration in Three Dimensions (Moissoglu et al., Methods Mol Biol, 2023). It presents a method to identify RNA spots in three-dimensional images and is tailored to quantitatively describe and compare distributions in the context of cells that exhibit front-back polarization. The analysis pipeline was implemented on mRNA distributions at the front cytoplasm of invasive leader cancer cells. However, it can be applicable in various other settings of front-back polarization or more broadly in cases of polarization along a linear axis. The analysis can additionally be applied in other cell types or methods of RNA imaging making it of broad potential applicability.