Diffusion and interaction dynamics of the cytosolic peroxisomal import receptor PEX5

Abstract

Peroxisomes fulfil many anabolic and catabolic functions, thereby importing all required proteins post-translationally from the cytosol. Dysfunction of the peroxisomal import process leads to severe diseases making this process a study of utmost importance. Peroxisomal proteins are recognized in the cytosol by the import receptor PEX5 and transported towards the peroxisomal membrane. Here we study the diffusion of the cargo loaded receptor in the cytosol by combining advanced live-cell microscopy and spectroscopy techniques such as fluorescence correlation spectroscopy (FCS) and superresolution STED and Minflux microscopy to present a detailed characterization of the diffusion and thus interaction dynamics as well as spatial organization of the peroxisomal import receptor PEX5.