Fig. 1: The proteasome is recruited to the mitochondria during cellular quiescence.

A Model of Insulin-AKT-GSK3 regulation of mitochondrial respiration quiescence (MRQ). Created with Biorender. B Proteasome activity from st1–8 oocytes(active), st14 oocytes(quiescent), and embryos (collected 0–2h and 16–20 h posted egg laying) (n = 4 completely independent experiments on independent samples). C In-gel hydrolysis assay to examine total proteasome activity in st1–8 and st14 eggs. This experiment was replicated 3 times with biological replicates. D Western blotting examines K48 ubiquitin levels in total cell lysis in st1–8 and st14 eggs. E Mitochondria-associated proteasome activity in st1–8 and st14 oocytes (n = 6 independent biological replicates). F In-gel hydrolysis assay examine mitochondria-associated proteasome activity in st1–8 and st14 eggs. This experiment was replicated 3 times with biological replicates. G Western blotting to examine K48 ubiquitin levels in mitochondrial fractions in st1–8 and st14 eggs. This experiment was replicated 3 times with biological replicates. H Native Western blotting gels to examine 20 S core and 19 S regulatory components of the assembled proteasome in total cell lysis from st1–8 and st14 eggs. This experiment was replicated 3 times with biological replicates. I TMRE mitochondrial membrane potential staining of wild-type ovarioles treated with DMSO or proteasome inhibitor MG132 (50 µM, 2 h). All error bars represent 1 X standard deviation. J Summary of the effects of proteasome inhibitor MG132 (50 µM, 2 h) on TMRE mitochondrial membrane potential staining in the indicated stages. These data are normalized to the TMRE staining in the adjacent follicle cell (n = >20 biological replicates). In the box-and-whisker plots, the box represents the upper and lower quartiles and the line within the box is the mean. The whiskers represent the maximum and minimum values. P values were calculated by one-way analysis of variance (ANOVA). Error bars represent one standard deviation. ^**p < 0.001, ^*p < 0.05. Error bars represent 1X standard deviation.