Structural mechanism of intracellular autoregulation of zinc uptake in ZIP transporters.
Pang, C., Chai, J., Zhu, P., Shanklin, J., Liu, Q.(2023) Nat Commun 14: 3404-3404
- PubMed: 37296139 
- DOI: https://doi.org/10.1038/s41467-023-39010-6
- Primary Citation of Related Structures:  
8GHT - PubMed Abstract: 
Zinc is an essential micronutrient that supports all living organisms through regulating numerous biological processes. However, the mechanism of uptake regulation by intracellular Zn 2+ status remains unclear. Here we report a cryo-electron microscopy structure of a ZIP-family transporter from Bordetella bronchiseptica at 3.05 Å resolution in an inward-facing, inhibited conformation. The transporter forms a homodimer, each protomer containing nine transmembrane helices and three metal ions. Two metal ions form a binuclear pore structure, and the third ion is located at an egress site facing the cytoplasm. The egress site is covered by a loop, and two histidine residues on the loop interact with the egress-site ion and regulate its release. Cell-based Zn 2+ uptake and cell growth viability assays reveal a negative regulation of Zn 2+ uptake through sensing intracellular Zn 2+ status using a built-in sensor. These structural and biochemical analyses provide mechanistic insight into the autoregulation of zinc uptake across membranes.
Organizational Affiliation: 
Biology Department, Brookhaven National Laboratory, Upton, NY, USA.