Aravindan Nitya, Vitali Daniela G, Breuer Julia, Oberst Jessica, Zalckvar Einat, Schuldiner Maya, Rapaport Doron
Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany.
Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel.
EMBO Rep. 2025 May;26(10):2622-2653. doi: 10.1038/s44319-025-00440-6. Epub 2025 Apr 2.
Most cellular proteins require targeting to a distinct cellular compartment to function properly. A subset of proteins is distributed to two or more destinations in the cell and little is known about the mechanisms controlling the process of dual/multiple targeting. Here, we provide insight into the mechanism of dual targeting of proteins between mitochondria and peroxisomes. We perform a high throughput microscopy screen in which we visualize the location of the model tail-anchored proteins Fis1 and Gem1 in the background of mutants in virtually all yeast genes. This screen identifies three proteins, whose absence results in a higher portion of the tail-anchored proteins in peroxisomes: the two paralogues Tom70, Tom71, and the uncharacterized gene YNL144C that we rename mitochondria and peroxisomes factor 1 (Mpf1). We characterize Mpf1 to be an unstable protein that associates with the cytosolic face of the mitochondrial outer membrane. Furthermore, our study uncovers a unique contribution of Tom71 to the regulation of dual targeting. Collectively, our study reveals, for the first time, factors that influence the dual targeting of proteins between mitochondria and peroxisomes.
大多数细胞蛋白质需要被靶向运输到特定的细胞区室才能正常发挥功能。有一部分蛋白质会被分配到细胞中的两个或更多个目的地，而对于控制双重/多重靶向运输过程的机制我们却知之甚少。在此，我们深入探究了蛋白质在线粒体和过氧化物酶体之间双重靶向运输的机制。我们进行了一项高通量显微镜筛选，在几乎所有酵母基因的突变体背景下，观察模型尾锚定蛋白Fis1和Gem1的定位。该筛选鉴定出三种蛋白质，缺失它们会导致尾锚定蛋白在过氧化物酶体中的比例升高：两个同源蛋白Tom70、Tom71，以及我们重新命名为线粒体和过氧化物酶体因子1（Mpf1）的未表征基因YNL144C。我们将Mpf1鉴定为一种不稳定蛋白，它与线粒体外膜的胞质面相关联。此外，我们的研究揭示了Tom71在双重靶向运输调控中的独特作用。总的来说，我们的研究首次揭示了影响蛋白质在线粒体和过氧化物酶体之间双重靶向运输的因素。
