FCU1 fusion protein (FCU1)

The FCU1 fusion protein is a therapeutic gene composed of two yeast-derived enzymes: cytosine deaminase (CD) and uracil phosphoribosyltransferase (UPRT), genetically linked in a single polypeptide. This fusion efficiently converts 5-fluorocytosine, a nontoxic antifungal agent, into 5-fluorouracil, a highly cytotoxic chemotherapeutic, thereby inducing selective death of gene-transfected tumor cells. It further increases tumor cell sensitivity to 5-fluorouracil via its UPRT activity. Used as a 'suicide gene' in cancer gene therapy, FCU1 can be delivered by viral vectors to tumors, enabling localized drug activation and bystander cell killing, addressing some limitations of classical prodrug strategies

Other names

FCU1 hybrid proteinyeast cytosine deaminase-uracil phosphoribosyltransferase fusion proteinsuicide gene fusion protein

Conversion of 5-fluorocytosine—a non-toxic prodrug—into 5-fluorouracil, a cytotoxic chemotherapeutic, thus selectively killing transfected tumor cells Uracil phosphoribosyltransferase activity also increases sensitivity to 5-fluorouracil