pr0c00506_si_004.xlsx (13.68 MB)
Download fileProteomic Profiling of Mitochondrial-Derived Vesicles in Brain Reveals Enrichment of Respiratory Complex Sub-assemblies and Small TIM Chaperones
dataset
posted on 27.11.2020, 02:31 authored by Rosalind
F. Roberts, Andrew N. Bayne, Thomas Goiran, Dominique Lévesque, François-Michel Boisvert, Jean-François Trempe, Edward A. FonThe
generation of mitochondrial-derived vesicles (MDVs) is implicated
in a plethora of vital cell functions, from mitochondrial quality
control to peroxisomal biogenesis. The discovery of distinct subtypes
of MDVs has revealed the selective inclusion of mitochondrial cargo
in response to varying stimuli. However, the true scope and variety
of MDVs is currently unclear, and unbiased approaches have yet to
be used to understand their biology. Furthermore, as mitochondrial
dysfunction has been implicated in many neurodegenerative diseases,
it is essential to understand MDV pathways in the nervous system.
To address this, we sought to identify the cargo in brain MDVs. We
used an in vitro budding assay and proteomic approach
to identify proteins selectively enriched in MDVs. 72 proteins were
identified as MDV-enriched, of which 31% were OXPHOS proteins. Interestingly,
the OXPHOS proteins localized to specific modules of the respiratory
complexes, hinting at the inclusion of sub-assemblies in MDVs. Small
TIM chaperones were also highly enriched in MDVs, linking mitochondrial
chaperone-mediated protein transport to MDV formation. As the two
Parkinson’s disease genes PINK1 and Parkin have been previously
implicated in MDV biogenesis in response to oxidative stress, we compared
the MDV proteomes from the brains of wild-type mice with those of
PINK1‑/‑ and Parkin‑/‑ mice. No significant difference was found, suggesting that PINK1-
and Parkin-dependent MDVs make up a small proportion of all MDVs in
the brain. Our findings demonstrate a previously uncovered landscape
of MDV complexity and provide a foundation from which further novel
MDV functions can be discovered. Data are available via ProteomeXchange
with identifier PXD020197.