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The mitochondrial surface receptor Tom70 protects the cytosol against mitoprotein-induced stress

ABSTRACT: Most mitochondrial proteins are synthesized as precursor proteins in the cytosol and post-translationally transported into mitochondria. The mitochondrial surface protein Tom70 acts at the interface of the cytosol and mitochondria. In vitro import experiments identified Tom70 as targeting receptor, particularly for hydrophobic carriers. Using in vivo methods, we revisited the Tom70 function, confirming that it supports the biogenesis of carriers and other mitochondrial proteins which considerably expands the set of Tom70-dependent mitochondrial proteins. However, the crucial activity of Tom70 is its recruitment of cytosolic chaperones to the outer membrane. Surprisingly, tethering an unrelated chaperone-binding domain onto the mitochondrial surface complements most of the defects caused by the absence of Tom70. In vivo, small single spanning inner membrane proteins can be particularly problematic when present in excess and the chaperone-binding ability of Tom70 is crucial to suppress their proteotoxicity. Thus, the predominant function of Tom70 is more that of a cytosolic co-chaperone, and its role as mitochondria-specifying receptor apparently is of less immediate relevance.

INSTRUMENT(S): Q Exactive HF

ORGANISM(S): Saccharomyces Cerevisiae (baker's Yeast)

TISSUE(S): Cell Culture

SUBMITTER: Robin Roth

LAB HEAD: Zuzana Storchova

PROVIDER: PXD021173 | Pride | 2021-03-29

REPOSITORIES: Pride

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			Action	DRS
	20200130_HF1_MaRa_SA_C0027_P0058B_TAH1_TMT_SS_01.raw	Raw
	20200130_HF1_MaRa_SA_C0027_P0058B_TAH1_TMT_SS_02.raw	Raw
	20200229_HF1_MaRa_SA_C0028_P0058C_TAH1_TMT_SS_03.raw	Raw
	andromeda.zip	Other
	txt.zip	Other

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