Dataset Information

Quantifying and Localizing the Mitochondrial Proteome Across Five Tissues in A Mouse Population.

ABSTRACT: We have used SWATH mass spectrometry to quantify 3648 proteins across 76 proteomes collected from genetically diverse BXD mouse strains in two fractions (mitochondria and total cell) from five tissues: liver, quadriceps, heart, brain, and brown adipose (BAT). Across tissues, expression covariation between genes' proteins and transcripts-measured in the same individuals-broadly aligned. Covariation was however far stronger in certain subsets than others: only 8% of transcripts in the lowest expression and variance quintile covaried with their protein, in contrast to 65% of transcripts in the highest quintiles. Key functional differences among the 3648 genes were also observed across tissues, with electron transport chain (ETC) genes particularly investigated. ETC complex proteins covary and form strong gene networks according to tissue, but their equivalent transcripts do not. Certain physiological consequences, such as the depletion of ATP synthase in BAT, are thus obscured in transcript data. Lastly, we compared the quantitative proteomic measurements between the total cell and mitochondrial fractions for the five tissues. The resulting enrichment score highlighted several hundred proteins which were strongly enriched in mitochondria, which included several dozen proteins were not reported in literature to be mitochondrially localized. Four of these candidates were selected for biochemical validation, where we found MTAP, SOAT2, and IMPDH2 to be localized inside the mitochondria, whereas ABCC6 was in the mitochondria-associated membrane. These findings demonstrate the synergies of a multi-omics approach to study complex metabolic processes, and this provides a resource for further discovery and analysis of proteoforms, modified proteins, and protein localization.

SUBMITTER: Williams EG

PROVIDER: S-EPMC6126393 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:We used 8 strains the BXD mouse genetic reference population, including parents C57BL/6J and DBA/2J, to study the proteome of the heart, whole brain, liver, quadriceps, and brown adipose tissue (BAT) across 8 different genotypes. For each sample, we examined the proteome of the mitochondria, as well as the whole cell fraction (including mitochondria). Later, we supplemented this study with an additional 19 strains of BXD mouse, with one strain overlapping, in the BAT for both whole cell and mitochondrial extract to examine tissue-specific hypotheses generated from the original set of 8 strains. All together, these data allowed us to (1) examine proteome expression of the mitochondria, (2) examine differences in proteome expression across tissue, (3) examine differences in proteome expression across strain, and (4) examine all three of the preceding factors simultaneously against one-another. This allowed us to uncover several proteins which are expressed in the mitochondria but are not reported as such in the literature, of which we validated a few by traditional staining techniques. Furthermore, we compare our proteome data against transcriptome data gathered in the same individual mice. We observe (1) that differences in expression of genes involved in oxidative phosphorylation are far more tissue-dependent at the protein level than the transcript level, and (2) and we observe that the phenotypic relationship between BAT and thermogenesis is far more evident at the protein expression data than it is from the transcript expression. Together, these data provide two conclusions: (1) next-gen mass spectrometry proteomics techniques can identify organelle localizations that were not evident from other techniques (perhaps particularly those proteins which are expressed both inside and outside the mitochondria); and (2) proteome and transcriptome data are complimentary, and proteome data may help us find and test new hypotheses even for physiological pathways which have been well studied at the genetic and transcriptomic levels.

Dataset Information

Quantifying and Localizing the Mitochondrial Proteome Across Five Tissues in A Mouse Population.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets