Dataset Information

The Mammalian Cytosolic Thioredoxin Reductase Pathway Acts via a Membrane Protein to Reduce ER-localised Proteins

ABSTRACT: Folding of proteins entering the mammalian secretory pathway requires the insertion of the correct disulfide bonds. Disulfide formation involves both an oxidative pathway for their insertion and a reductive pathway to remove incorrectly formed disulfides. Reduction of these disulfides is critical for correct folding and degradation of misfolded proteins. Previously, we showed that the reductive pathway is driven by NADPH generated in the cytosol. Here, by reconstituting the pathway using purified proteins and ER microsomal membranes, we demonstrate that the thioredoxin reductase system provides the minimal cytosolic components required for reducing proteins within the ER lumen. In particular, saturation of the pathway and its protease sensitivity demonstrates the requirement for a membrane protein to shuttle electrons from the cytosol to the ER lumen. These results provide compelling evidence for the critical role of the cytosol in regulating ER redox homeostasis to ensure correct protein folding and to facilitate the degradation of misfolded ER proteins.

INSTRUMENT(S): Orbitrap Fusion Lumos

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Epithelial Cell

SUBMITTER: Sergio Lilla

LAB HEAD: Sara Rossana Zanivan

PROVIDER: PXD017923 | Pride | 2020-04-09

REPOSITORIES: Pride

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			Action	DRS
	2019418_SEL_LU_SA_NIB_EXT_040419_microsomes_SICyLIA-Hyp_LC-pH10_3h_f001.raw	Raw
	2019418_SEL_LU_SA_NIB_EXT_040419_microsomes_SICyLIA-Hyp_LC-pH10_3h_f002.raw	Raw
	2019418_SEL_LU_SA_NIB_EXT_040419_microsomes_SICyLIA-Hyp_LC-pH10_3h_f003.raw	Raw
	2019418_SEL_LU_SA_NIB_EXT_040419_microsomes_SICyLIA-Hyp_LC-pH10_3h_f004.raw	Raw
	2019418_SEL_LU_SA_NIB_EXT_040419_microsomes_SICyLIA-Hyp_LC-pH10_3h_f005.raw	Raw

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Publications

The mammalian cytosolic thioredoxin reductase pathway acts via a membrane protein to reduce ER-localised proteins.

Cao Xiaofei X Lilla Sergio S Cao Zhenbo Z Pringle Marie Anne MA Oka Ojore B V OBV Robinson Philip J PJ Szmaja Tomasz T van Lith Marcel M Zanivan Sara S Bulleid Neil J NJ

Journal of cell science 20200430 8

Folding of proteins entering the mammalian secretory pathway requires the insertion of the correct disulfides. Disulfide formation involves both an oxidative pathway for their insertion and a reductive pathway to remove incorrectly formed disulfides. Reduction of these disulfides is crucial for correct folding and degradation of misfolded proteins. Previously, we showed that the reductive pathway is driven by NADPH generated in the cytosol. Here, by reconstituting the pathway using purified prot ...[more]

PMID: 32184267

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