The interaction between SAMM50 and p62/SQSTM1 is important for OXPHOS-induced mitophagy. (A) Live cell images of WT and p62 KO MEF cells stably expressing mCherry-ATG13 grown in glucose media or glucose-free acetoacetate-containing media for 96 h. Cells were stained with MitoTracker. Enlarged insets are indicated. Scale bars, 10 µm (main), 2 µm (inset). (B) ATG13 puncta quantified per cell in A in ∼60 cells for each treatment. Values are mean ± SD. ***, P < 0.001; †, NS; one-way ANOVA. (C) Live-cell images of WT and p62 KO MEFs stably expressing mCherry-GABARAP grown in glucose or acetoacetate media for 96 h and stained with MitoTracker. Scale bars, 10 µm (main), 2 µm (inset). (D) GABARAP puncta per cell quantified in C in ∼60 cells for each treatment. Values are mean ± SD. **, P < 0.005; †, NS; one-way ANOVA. (E) Immunoblots of lysates of WT, p62 KO, and p62 KO MEFs reconstituted with Myc-p62 or Myc-p62 Δ170–256 stably expressing COX8-EGFP-mCherry. (F) Live-cell images of p62 KO MEFs and p62 KO MEFs reconstituted with Myc-p62 or Myc-p62 Δ170–256 stably expressing COX8-EGFP-mCherry grown in media containing acetoacetate for 96 h. Scale bars, 20 µm (main), 5 µm (inset). (G) Percentage of cells with red-only dots signifying mitophagy quantified in F from three different experiments. Values are mean ± SD. ***, P < 0.001; **, P < 0.005; one-way ANOVA. (H) Model for basal piecemeal and OXPHOS-induced mitophagy. SAMM50 interacts with SAM and MICOS complex proteins and recruits hATG8 and p62 to these fragments. The fragments are recruited to p62 puncta, which mark sites of forming autophagosomes. The fragmented mitochondria are enclosed in the autophagosome and subsequently degraded in the lysosome.
Figure 9.

The interaction between SAMM50 and p62/SQSTM1 is important for OXPHOS-induced mitophagy. (A) Live cell images of WT and p62 KO MEF cells stably expressing mCherry-ATG13 grown in glucose media or glucose-free acetoacetate-containing media for 96 h. Cells were stained with MitoTracker. Enlarged insets are indicated. Scale bars, 10 µm (main), 2 µm (inset). (B) ATG13 puncta quantified per cell in A in ∼60 cells for each treatment. Values are mean ± SD. ***, P < 0.001; †, NS; one-way ANOVA. (C) Live-cell images of WT and p62 KO MEFs stably expressing mCherry-GABARAP grown in glucose or acetoacetate media for 96 h and stained with MitoTracker. Scale bars, 10 µm (main), 2 µm (inset). (D) GABARAP puncta per cell quantified in C in ∼60 cells for each treatment. Values are mean ± SD. **, P < 0.005; †, NS; one-way ANOVA. (E) Immunoblots of lysates of WT, p62 KO, and p62 KO MEFs reconstituted with Myc-p62 or Myc-p62 Δ170–256 stably expressing COX8-EGFP-mCherry. (F) Live-cell images of p62 KO MEFs and p62 KO MEFs reconstituted with Myc-p62 or Myc-p62 Δ170–256 stably expressing COX8-EGFP-mCherry grown in media containing acetoacetate for 96 h. Scale bars, 20 µm (main), 5 µm (inset). (G) Percentage of cells with red-only dots signifying mitophagy quantified in F from three different experiments. Values are mean ± SD. ***, P < 0.001; **, P < 0.005; one-way ANOVA. (H) Model for basal piecemeal and OXPHOS-induced mitophagy. SAMM50 interacts with SAM and MICOS complex proteins and recruits hATG8 and p62 to these fragments. The fragments are recruited to p62 puncta, which mark sites of forming autophagosomes. The fragmented mitochondria are enclosed in the autophagosome and subsequently degraded in the lysosome.

This Feature Is Available To Subscribers Only

or Create an Account

Close Modal
Close Modal