Metalloreductase STEAP2 (Six-transmembrane epithelial antigen of the prostate 2) (STEAP2)

Metalloreductase STEAP2 is a membrane-embedded hemprotein encoded by the STEAP2 gene located on chromosome 7q21, functioning as a NADPH-dependent ferric-chelate reductase that mediates cross-membrane electron transfer for iron and copper reduction. The protein is predominantly expressed in prostate epithelial cells, with localization to the plasma membrane and Golgi complex. STEAP2 plays a critical role in prostate cancer progression, with significantly elevated expression in both primary and hormone-refractory prostate carcinomas compared to benign prostate tissue. The protein's knockdown reduces cancer cell invasiveness, promotes apoptosis, and decreases cell migration, demonstrating its functional importance in oncogenic processes. As a highly specific, cell-surface antigen expressed at all stages of prostate cancer independent of androgen signaling, STEAP2 represents a promising diagnostic and therapeutic target for prostate cancer management.

Other names

STAMP1 (six transmembrane protein of prostate 1)

STEAP2 functions as a NADPH-dependent ferric-chelate reductase, using NADPH from one side of the membrane to reduce Fe³⁺ chelate. The protein mediates cross-membrane electron transfer from NADPH via FAD and heme. It also exhibits ferri reductase and cupric reductase activity, stimulating cellular uptake of iron and copper in vitro.