Diffusion and interaction dynamics of the cytosolic peroxisomal import receptor PEX5

S Galiani; K Reglinski; P Carravilla; A Barbotin; I Urbančič; J Ott; J Sehr; E Sezgin; F Schneider; D Waithe; P Hublitz; W Schliebs; R Erdmann; C Eggeling

doi:10.1016/j.bpr.2022.100055

Diffusion and interaction dynamics of the cytosolic peroxisomal import receptor PEX5

Biophys Rep (N Y). 2022 Jun 8;2(2):None. doi: 10.1016/j.bpr.2022.100055.

Authors

S Galiani^{1

2}, K Reglinski^{1

3

4

5}, P Carravilla^{3

4

6

7}, A Barbotin^{1

8}, I Urbančič^{1

9}, J Ott¹⁰, J Sehr¹⁰, E Sezgin^{1

11}, F Schneider¹², D Waithe^{2

13}, P Hublitz¹⁴, W Schliebs¹⁰, R Erdmann¹⁰, C Eggeling^{1

2

3

4

15}

Affiliations

¹ MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK.
² Wolfson Imaging Centre, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK.
³ Leibniz-Institute of Photonic Technologies e.V., Jena, Germany.
⁴ Institute of Applied Optic and Biophysics, Friedrich-Schiller University Jena, Jena, Germany.
⁵ University Hospital Jena, Jena, Germany.
⁶ Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain.
⁷ Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country, Leioa, Spain.
⁸ Department of Engineering Science, University of Oxford, Oxford, UK.
⁹ Laboratory of Biophysics, Condensed Matter Physics Department, Jožef Stefan Institute, Ljubljana, Slovenia.
¹⁰ Institute of Biochemistry and Pathobiochemistry, Systems Biochemistry, Ruhr-University Bochum, Bochum, Germany.
¹¹ Science for Life Laboratory, Department of Women's and Children's Health, Karolinska Institutet, Solna, Sweden.
¹² Kennedy Institute for Rheumatology, University of Oxford, Oxford, UK.
¹³ WIMM Centre for Computational Biology , MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK.
¹⁴ WIMM Genome Engineering Services, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK.
¹⁵ Jena Center for Soft Matter (JCSM), Jena, Germany.

Abstract

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.

Abstract

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