TRP14 is the rate limiting enzyme for intracellular cystine reduction and regulates proteome cysteinylation. 42 proteins showed higher cysteinylation levels in TRP14 knockdown cells compared to wild-type cells upon biotinylated cysteine incubation and subsequent streptavidin pulldown. Figure 2C.

ABSTRACT: It has remained unknown how cells reduce cystine taken up from the extracellular space, which is a required step for further utilization of cysteine in key processes such as protein or glutathione synthesis. Here we show that the thioredoxin-related protein of 14 kDa (TRP14, encoded by TXNDC17) is the rate limiting enzyme for intracellular cystine reduction. When TRP14 is genetically knocked out, cysteine synthesis through the transsulfuration pathway becomes the major source of cysteine in human cells, and knockout of both pathways becomes lethal in C. elegans subjected to proteostatic stress. TRP14 can also reduce cysteinyl moieties on proteins, rescuing their activities as here shown with cysteinylated peroxiredoxin 2. Txndc17 knock-out mice were, surprisingly, protected in an acute pancreatitis model, concomitant with activation of Nrf2-driven antioxidant pathways and upregulation of transsulfuration. We conclude that TRP14 is the evolutionary conserved enzyme principally responsible for intracellular cystine reduction in C. elegans, mice and humans.

INSTRUMENT(S): TripleTOF 5600

ORGANISM(S): Homo Sapiens (human)

SUBMITTER: Luz Valero  

LAB HEAD: Juan Sastre

PROVIDER: PXD038965 | Pride | 2024-06-05

REPOSITORIES: pride