ZRT And IRT Related Protein 3 (ZIP3)

ZIP1 (SLC39A1), ZIP2 (SLC39A2), and ZIP3 (SLC39A3). The 3 deduced human proteins share greater than 49% similarity.By immunohistochemistry analysis of human normal and malignant prostate tissue sections, they determined that, like SLC39A1, both SLC39A2 and SLC39A3 are downregulated in malignant cells in situ along with the depletion of zinc levels. SLC39A2 and SLC39A3 were localized predominantly at the apical cell membrane, which is in contrast to the SLC39A1 localization at the basolateral membrane.

SLC39A1 is important for the extraction of zinc from circulation as the primary source of cellular zinc, whereas SLC39A2 and SLC39A3 are important for retention of the zinc in the cellular compartment.