Molecular insights into substrate translocation in an elevator-type metal transporter

Abstract: Solute carrier (SLC) transporters govern the selective transport of diverse molecules across cell membranes, controlling fundamental metabolic and cellular processes. Despite genetic evidence implicating SLC transporters in a variety of human diseases, this family of proteins represents an underexplored target class for therapeutic drug discovery. Here, we discovered a selective potentiator of SLC39A8, a metal transporter associated with inflammatory bowel disease, schizophrenia, and cardiovascular and metabolic disorders. We conducted a drug repurposing screen, identifying efavirenz as a potentiator of manganese and cadmium uptake by SLC39A8 and subsequently generated structure-activity relationships to guide design of analogs. Computational pocket identification methodology and molecular dynamic simulations revealed a ligandable, cryptic pocket that, together with functional mutagenesis, indicated direct target engagement and allosteric modulation. Our findings demonstrate how the combination of experimental data and computational tools represents a powerful synergy that can enhance scientific outcomes. This integrated approach allowed for iterative feedback where insights from experiments informed the model refinements and computational predictions guided future experimental designs. Furthermore, our data established that SLC39A8 transporter activity can be increased pharmacologically, potentially opening avenues for SLC transporter drug discovery.

TL;DR: The results identify a previously uncharacterized role of ZIP4 in pancreatic cancer progression, and indicate that knocking down ZIP4 by short hairpin RNA might be a novel treatment strategy for pancreatic cancers with ZIP4 overexpression.