Description
Cysteine plays an essential role in cellular redox homoeostasis as a key constituent of the tripeptide glutathione (GSH).
A rate limiting step in cellular GSH synthesis is the availability of cysteine.
However, circulating cysteine exists in the blood as the oxidised di-peptide cystine, requiring specialised transport systems for its import into the cell.
System xc- is a dedicated cystine transporter, importing cystine in exchange for intracellular glutamate.
To counteract elevated levels of reactive oxygen species in cancerous cells system xc- is frequently upregulated, making it an attractive target for anticancer therapies