1. Academic Validation
  2. Plekhg5 controls the unconventional secretion of Sod1 by presynaptic secretory autophagy

Plekhg5 controls the unconventional secretion of Sod1 by presynaptic secretory autophagy

  • Nat Commun. 2024 Oct 4;15(1):8622. doi: 10.1038/s41467-024-52875-5.
Amy-Jayne Hutchings # 1 Bita Hambrecht # 1 Alexander Veh # 1 Neha Jadhav Giridhar 1 Abdolhossein Zare 1 Christina Angerer 1 Thorben Ohnesorge 1 Maren Schenke 2 3 Bhuvaneish T Selvaraj 4 5 6 Siddharthan Chandran 4 5 6 Jared Sterneckert 7 8 Susanne Petri 9 Bettina Seeger 2 Michael Briese 1 Christian Stigloher 10 Thorsten Bischler 11 Andreas Hermann 12 13 14 Markus Damme 15 Michael Sendtner 1 Patrick Lüningschrör 16
Affiliations

Affiliations

  • 1 Institute of Clinical Neurobiology, University Hospital Würzburg, Würzburg, Germany.
  • 2 Institute for Food Quality and Safety, Research Group Food Toxicology and Alternative/Complementary Methods to Animal Experiments, University of Veterinary Medicine Hannover, Hannover, Germany.
  • 3 Bloomberg School of Public Health, Center for Alternatives to Animal Testing, Johns Hopkins University, Baltimore, MD, USA.
  • 4 Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, EH16 4SB, UK.
  • 5 UK Dementia Research Institute at University of Edinburgh, University of Edinburgh, Edinburgh, EH16 4SB, UK.
  • 6 Anne Rowling Regenerative Neurology Clinic, University of Edinburgh, Edinburgh, EH16 4SB, UK.
  • 7 Center for Regenerative Therapies TU Dresden, Fetscherstr. 105, 01307, Dresden, Germany.
  • 8 Medical Faculty Carl Gustav Carus of TU Dresden, Dresden, Germany.
  • 9 Department of Neurology, Hannover Medical School, Hannover, Germany.
  • 10 Imaging Core Facility, Biocenter, University of Würzburg, 97074, Würzburg, Germany.
  • 11 Core Unit Systems Medicine, University of Würzburg, D-97080, Würzburg, Germany.
  • 12 Translational Neurodegeneration Section Albrecht-Kossel, Department of Neurology, University Medical Center Rostock, Rostock, Germany.
  • 13 Center for Transdisciplinary Neurosciences Rostock, University Medical Center Rostock, Rostock, Germany.
  • 14 Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE) Rostock/Greifswald, 18147, Rostock, Germany.
  • 15 Institute of Biochemistry, Christian-Albrechts-University Kiel, Olshausenstr. 40, 24098, Kiel, Germany.
  • 16 Institute of Clinical Neurobiology, University Hospital Würzburg, Würzburg, Germany. Lueningsch_P@ukw.de.
  • # Contributed equally.
Abstract

Increasing evidence suggests an essential function for Autophagy in unconventional protein secretion (UPS). However, despite its relevance for the secretion of aggregate-prone proteins, the mechanisms of secretory Autophagy in neurons have remained elusive. Here we show that the lower motoneuron disease-associated guanine exchange factor Plekhg5 drives the UPS of Sod1. Mechanistically, Sod1 is sequestered into autophagosomal carriers, which subsequently fuse with secretory lysosomal-related organelles (LROs). Exocytosis of LROs to release Sod1 into the extracellular milieu requires the activation of the small GTPase Rab26 by Plekhg5. Deletion of Plekhg5 in mice leads to the accumulation of Sod1 in LROs at swollen presynaptic sites. A reduced secretion of toxic ALS-linked SOD1G93A following deletion of Plekhg5 in SOD1G93A mice accelerated disease onset while prolonging survival due to an attenuated microglia activation. Using human iPSC-derived motoneurons we show that reduced levels of PLEKHG5 cause an impaired secretion of ALS-linked SOD1. Our findings highlight an unexpected pathophysiological mechanism that converges two motoneuron disease-associated proteins into a common pathway.

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