Functional Characterisation of the Autophagy ATG12~5/16 Complex in Dictyostelium discoideum

Karow M, Fischer S, Meßling S, Konertz R, Riehl J, Xiong Q, Rijal R, Wagle P, Clemen CS, Eichinger L (2020)

Publication Type: Journal article

Publication year: 2020

Journal

Cells MDPI

Book Volume: 9

Journal Issue: 5

DOI: 10.3390/cells9051179

Abstract

Macroautophagy, a highly conserved and complex intracellular degradative pathway, involves more than 20 core autophagy (ATG) proteins, among them the hexameric ATG12~5/16 complex, which is part of the essential ubiquitin-like conjugation systems in autophagy. Dictyostelium discoideumatg5 single, atg5/12 double, and atg5/12/16 triple gene knock-out mutant strains displayed similar defects in the conjugation of ATG8 to phosphatidylethanolamine, development, and cell viability upon nitrogen starvation. This implies that ATG5, 12 and 16 act as a functional unit in canonical autophagy. Macropinocytosis of TRITC dextran and phagocytosis of yeast were significantly decreased in ATG5¯ and ATG5¯/12¯ and even further in ATG5¯/12¯/16¯ cells. In contrast, plaque growth on Klebsiella aerogenes was about twice as fast for ATG5¯ and ATG5¯/12¯/16¯ cells in comparison to AX2, but strongly decreased for ATG5¯/12¯ cells. Along this line, phagocytic uptake of Escherichia coli was significantly reduced in ATG5¯/12¯ cells, while no difference in uptake, but a strong increase in membrane association of E. coli, was seen for ATG5¯ and ATG5¯/12¯/16¯ cells. Proteasomal activity was also disturbed in a complex fashion, consistent with an inhibitory activity of ATG16 in the absence of ATG5 and/or ATG12. Our results confirm the essential function of the ATG12~5/16 complex in canonical autophagy, and furthermore are consistent with autophagy-independent functions of the complex and its individual components. They also strongly support the placement of autophagy upstream of the ubiquitin-proteasome system (UPS), as a fully functional UPS depends on autophagy.

Additional Organisation(s)

Institute of Neuropathology

Involved external institutions

Universität zu Köln DE Germany (DE) Shanxi University (SXU) / 山西大学 CN China (CN) Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR) / German Aerospace Center DE Germany (DE) Texas A&M University US United States (USA) (US)

How to cite

APA:

Karow, M., Fischer, S., Meßling, S., Konertz, R., Riehl, J., Xiong, Q.,... Eichinger, L. (2020). Functional Characterisation of the Autophagy ATG12~5/16 Complex in Dictyostelium discoideum. Cells, 9(5). https://dx.doi.org/10.3390/cells9051179

MLA:

Karow, Malte, et al. "Functional Characterisation of the Autophagy ATG12~5/16 Complex in Dictyostelium discoideum." Cells 9.5 (2020).

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