Download MendeleyStructure of the human cation-chloride cotransporter NKCC1 determined by single-particle electron cryo-microscopy.
Yang, X., Wang, Q., Cao, E.(2020) Nat Commun 11: 1016-1016
- PubMed: 32081947
- DOI: https://doi.org/10.1038/s41467-020-14790-3
- Primary Citation of Related Structures:
6PZT - PubMed Abstract:
The secondary active cation-chloride cotransporters (CCCs) utilize the existing Na + and/or K + gradients to move Cl - into or out of cells. NKCC1 is an intensively studied member of the CCC family and plays fundamental roles in regulating trans-epithelial ion movement, cell volume, chloride homeostasis and neuronal excitability. Here, we report a cryo-EM structure of human NKCC1 captured in a partially loaded, inward-open state. NKCC1 assembles into a dimer, with the first ten transmembrane (TM) helices harboring the transport core and TM11-TM12 helices lining the dimer interface. TM1 and TM6 helices break α-helical geometry halfway across the lipid bilayer where ion binding sites are organized around these discontinuous regions. NKCC1 may harbor multiple extracellular entryways and intracellular exits, raising the possibility that K + , Na + , and Cl - ions may traverse along their own routes for translocation. NKCC1 structure provides a blueprint for further probing structure-function relationships of NKCC1 and other CCCs.
Organizational Affiliation:
Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, 84112-5650, USA.
