Galiani S, Reglinski K, Carravilla P, Barbotin A, Urbančič I, Ott J, Sehr J, Sezgin E, Schneider F, Waithe D, Hublitz P, Schliebs W, Erdmann R, Eggeling C
MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK.
Wolfson Imaging Centre, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK.
Biophys Rep (N Y). 2022 Jun 8;2(2):None. doi: 10.1016/j.bpr.2022.100055.
Cellular functions rely on proper actions of organelles such as peroxisomes. These organelles rely on the import of proteins from the cytosol. The peroxisomal import receptor PEX5 takes up target proteins in the cytosol and transports them to the peroxisomal matrix. However, its cytosolic molecular interactions have so far not directly been disclosed. Here, we combined advanced optical microscopy and spectroscopy techniques such as fluorescence correlation spectroscopy and stimulated emission depletion microscopy with biochemical tools to present a detailed characterization of the cytosolic diffusion and interaction dynamics of PEX5. Among other features, we highlight a slow diffusion of PEX5, independent of aggregation or target binding, but associated with cytosolic interaction partners via its N-terminal domain. This sheds new light on the functionality of the receptor in the cytosol as well as highlighting the potential of using complementary microscopy tools to decipher molecular interactions in the cytosol by studying their diffusion dynamics.
细胞功能依赖于过氧化物酶体等细胞器的正常运作。这些细胞器依赖于从细胞质中导入蛋白质。过氧化物酶体导入受体PEX5在细胞质中摄取靶蛋白并将其转运到过氧化物酶体基质中。然而，其在细胞质中的分子相互作用迄今尚未直接揭示。在这里，我们将先进的光学显微镜和光谱技术，如荧光相关光谱和受激发射损耗显微镜，与生化工具相结合，以详细表征PEX5在细胞质中的扩散和相互作用动力学。在其他特征中，我们强调PEX5的缓慢扩散，这与聚集或靶标结合无关，但通过其N端结构域与细胞质相互作用伙伴相关联。这为该受体在细胞质中的功能提供了新的线索，同时也突出了利用互补显微镜工具通过研究其扩散动力学来破译细胞质中分子相互作用的潜力。
