Mitochondria are essential for cell viability. Without functioning mitochondria, the cell cannot be supplied with the energy it needs to survive. Mitochondrial function relies heavily on import of proteins; this is because the proteome is almost exclusively encoded by nuclear genes (Weidberg). When import is prohibited, the mitochondria will send out several mitochondria-to-nucleus signals to try and resolve the issue.
The first pathway mentioned in the article is the mtUPR (Mito-Nucleus Signaling Pathway). If proteins are not entering the mitochondrial due to folding errors, then this signal is sent and “triggers the expression of mitochondrial chaperones”(Weidberg), which aid in the correct folding and transportation of proteins. The next two pathways both attempt to “reduce translation and induce degradation of unimported proteins in the cytosol” (Weidberg). They are the UPRam (Unfolded Protein Response Activated by Mistargeting of Proteins) and the mPOS (Mitochondrial Precursor Over-Accumulation Stress) pathways.
The purpose of the experiment was to “determine how cells respond to defects in mitochondrial protein import” (Weidberg). This direction of research was determined because the researches found a lack in literature about the “response to protein import defects that protect the mitochondria during stress” …show more content…
Through budding yeast, the researchers developed an unexplained system that allowed them to overexpress proteins that “rely on a bipartite signal sequence for their mitochondrial localization inhibited mitochondrial import” (Weidberg). This led to the accumulation of unimported proteins or mitochondrial precursors. Protease protection and carbonate extraction assays were performed on the isolated mitochondria to reveal that the proteins has accumulated on the mitochondrial surface and in the transport channels
The first pathway mentioned in the article is the mtUPR (Mito-Nucleus Signaling Pathway). If proteins are not entering the mitochondrial due to folding errors, then this signal is sent and “triggers the expression of mitochondrial chaperones”(Weidberg), which aid in the correct folding and transportation of proteins. The next two pathways both attempt to “reduce translation and induce degradation of unimported proteins in the cytosol” (Weidberg). They are the UPRam (Unfolded Protein Response Activated by Mistargeting of Proteins) and the mPOS (Mitochondrial Precursor Over-Accumulation Stress) pathways.
The purpose of the experiment was to “determine how cells respond to defects in mitochondrial protein import” (Weidberg). This direction of research was determined because the researches found a lack in literature about the “response to protein import defects that protect the mitochondria during stress” …show more content…
Through budding yeast, the researchers developed an unexplained system that allowed them to overexpress proteins that “rely on a bipartite signal sequence for their mitochondrial localization inhibited mitochondrial import” (Weidberg). This led to the accumulation of unimported proteins or mitochondrial precursors. Protease protection and carbonate extraction assays were performed on the isolated mitochondria to reveal that the proteins has accumulated on the mitochondrial surface and in the transport channels