Journal: bioRxiv
Article Title: Dysregulation of a novel autophagosome-mitochondria contact contributes to autophagy dysfunction and neurodegeneration in tauopathy
doi: 10.64898/2026.03.23.713823
Figure Lengend Snippet: AV-Mito untethering relies on AV-bound TBC1D15 GAP activity and is required for autophagic cargo clearance in tauopathy axons. ( A and B ) Representative images ( A ) and quantitative analysis ( B ) of TBC1D15 localization in normal axons. Data were expressed as the percentage of AVs or mitochondria positive for TBC1D15 and quantified from the total numbers of AVs or mitochondria ( n , indicated in parentheses) from the axons of 51 neurons ( B ). Arrows: TBC1D15-positive AVs; arrowheads: a TBC1D15-negative AV in an AV-Mito contact; asterisk: mitophagosome. ( C and D ) Representative kymographs ( C ) and quantitative analysis ( D ) of TBC1D15-tagged AVs in axons with 24-hour trehalose incubation. The relative motility of AVs was quantified from the axons of 17 neurons as indicated in parentheses ( D ). Arrows: TBC1D15-tagged motile AVs. ( E - H ) Representative kymographs ( E ) and quantitative analysis ( F - H ) of AV-Mito contacts in axons expressing TBC1D15 or TBC1D15 D397A mutant. The data were quantified and expressed as AV-Mito contact duration and its frequency, the contact number per 100 μm axonal length, the percentage of AVs in contacts, and the relative motility of AVs. Data were quantified from the total numbers of neurons ( n ) and AV-Mito contacts (c) as indicated in parentheses ( F - H ). Arrows: AV-Mito contacts. ( I and J ) Representative images ( I ) and quantitative analysis ( J ) of p62 in tauP301S axons with and without OE of TBC1D15 or TBC1D15 D397A mutant. The data were quantified and expressed as GFP-p62 puncta number per 100 μm axonal length. Data were quantified from the total numbers of neurons ( n ) as indicated in parentheses ( J ). ( K and L ) Representative blots ( K ) and quantitative analysis ( L ) of tauP301S Tg neurons transduced with and without AAV-hTBC1D15. Protein intensities were normalized to those in control tauP301S neurons without TBC1D15 OE. Data were collected from two ( B and D ), three ( F-H and J ), or five ( L ) dissections. Data were expressed as the mean ± SEM and analyzed using linear mixed-effects models ( B , F - H , and J ) or by two-sided Student’s t -test ( L ). Scale bars: 10 μm.
Article Snippet: The AAV2/9-mCherry, AAV2/9-mCherry-hTBC1D15, and AAV2/9-mCherry-hTBC1D15 D397A mutant viruses were produced by Vector BioLabs.
Techniques: Activity Assay, Incubation, Expressing, Mutagenesis, Transduction, Control