Robust LC3B lipidation analysis by precisely adjusting autophagic flux
Autophagic flux can be quantified based on the accumulation of lipidated LC3B in the presence of late-stage autophagy inhibitors. This method has been widely applied to identify novel compounds that activate autophagy. Here we scrutinize this approach and show that bafilomycin A1 (BafA) but not chlo...
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| Main Authors: | , , , , , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
07 January 2022
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| In: |
Scientific reports
Year: 2022, Volume: 12, Pages: 1-14 |
| ISSN: | 2045-2322 |
| DOI: | 10.1038/s41598-021-03875-8 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1038/s41598-021-03875-8 Verlag, lizenzpflichtig, Volltext: https://www.nature.com/articles/s41598-021-03875-8 
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| Author Notes: | Martina P. Liebl, Sarah C. Meister, Lisa Frey, Kristina Hendrich, Anja Klemmer, Bettina Wohlfart, Christopher Untucht, Judith Nuber, Christian Pohl & Viktor Lakics |
| Summary: | Autophagic flux can be quantified based on the accumulation of lipidated LC3B in the presence of late-stage autophagy inhibitors. This method has been widely applied to identify novel compounds that activate autophagy. Here we scrutinize this approach and show that bafilomycin A1 (BafA) but not chloroquine is suitable for flux quantification due to the stimulating effect of chloroquine on non-canonical LC3B-lipidation. Significant autophagic flux increase by rapamycin could only be observed when combining it with BafA concentrations not affecting basal flux, a condition which created a bottleneck, rather than fully blocking autophagosome-lysosome fusion, concomitant with autophagy stimulation. When rapamycin was combined with saturating concentrations of BafA, no significant further increase of LC3B lipidation could be detected over the levels induced by the late-stage inhibitor. The large assay window obtained by this approach enables an effective discrimination of autophagy activators based on their cellular potency. To demonstrate the validity of this approach, we show that a novel inhibitor of the acetyltransferase EP300 activates autophagy in a mTORC1-dependent manner. We propose that the creation of a sensitized background rather than a full block of autophagosome progression is required to quantitatively capture changes in autophagic flux. |
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| Item Description: | Gesehen am 20.09.2022 |
| Physical Description: | Online Resource |
| ISSN: | 2045-2322 |
| DOI: | 10.1038/s41598-021-03875-8 |