Mechanism of anion exchange and small-molecule inhibition of pendrin

Abstract Pendrin (SLC26A4) is an anion exchanger that mediates bicarbonate (HCO3 −) exchange for chloride (Cl−) and is crucial for maintaining pH and salt homeostasis in the kidney, lung, and cochlea. Pendrin also exports iodide (I−) in the thyroid gland. Pendrin mutations in humans lead to Pendred...

Full description

Bibliographic Details
Main Authors: Lie Wang, Anthony Hoang, Eva Gil-Iturbe, Arthur Laganowsky, Matthias Quick, Ming Zhou
Format: Article
Language:English
Published: Nature Portfolio 2024-01-01
Series:Nature Communications
Online Access:https://doi.org/10.1038/s41467-023-44612-1
_version_ 1827388332683821056
author Lie Wang
Anthony Hoang
Eva Gil-Iturbe
Arthur Laganowsky
Matthias Quick
Ming Zhou
author_facet Lie Wang
Anthony Hoang
Eva Gil-Iturbe
Arthur Laganowsky
Matthias Quick
Ming Zhou
author_sort Lie Wang
collection DOAJ
description Abstract Pendrin (SLC26A4) is an anion exchanger that mediates bicarbonate (HCO3 −) exchange for chloride (Cl−) and is crucial for maintaining pH and salt homeostasis in the kidney, lung, and cochlea. Pendrin also exports iodide (I−) in the thyroid gland. Pendrin mutations in humans lead to Pendred syndrome, causing hearing loss and goiter. Inhibition of pendrin is a validated approach for attenuating airway hyperresponsiveness in asthma and for treating hypertension. However, the mechanism of anion exchange and its inhibition by drugs remains poorly understood. We applied cryo-electron microscopy to determine structures of pendrin from Sus scrofa in the presence of either Cl−, I−, HCO3 − or in the apo-state. The structures reveal two anion-binding sites in each protomer, and functional analyses show both sites are involved in anion exchange. The structures also show interactions between the Sulfate Transporter and Anti-Sigma factor antagonist (STAS) and transmembrane domains, and mutational studies suggest a regulatory role. We also determine the structure of pendrin in a complex with niflumic acid (NFA), which uncovers a mechanism of inhibition by competing with anion binding and impeding the structural changes necessary for anion exchange. These results reveal directions for understanding the mechanisms of anion selectivity and exchange and their regulations by the STAS domain. This work also establishes a foundation for analyzing the pathophysiology of mutations associated with Pendred syndrome.
first_indexed 2024-03-08T16:16:20Z
format Article
id doaj.art-6d6b2df95fe74449afcfd24d0974d2dc
institution Directory Open Access Journal
issn 2041-1723
language English
last_indexed 2024-03-08T16:16:20Z
publishDate 2024-01-01
publisher Nature Portfolio
record_format Article
series Nature Communications
spelling doaj.art-6d6b2df95fe74449afcfd24d0974d2dc2024-01-07T12:34:28ZengNature PortfolioNature Communications2041-17232024-01-0115111110.1038/s41467-023-44612-1Mechanism of anion exchange and small-molecule inhibition of pendrinLie Wang0Anthony Hoang1Eva Gil-Iturbe2Arthur Laganowsky3Matthias Quick4Ming Zhou5Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of MedicineVerna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of MedicineDepartment of Psychiatry, Columbia University Irving Medical CenterDepartment of Chemistry, Texas A&M UniversityDepartment of Psychiatry, Columbia University Irving Medical CenterVerna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of MedicineAbstract Pendrin (SLC26A4) is an anion exchanger that mediates bicarbonate (HCO3 −) exchange for chloride (Cl−) and is crucial for maintaining pH and salt homeostasis in the kidney, lung, and cochlea. Pendrin also exports iodide (I−) in the thyroid gland. Pendrin mutations in humans lead to Pendred syndrome, causing hearing loss and goiter. Inhibition of pendrin is a validated approach for attenuating airway hyperresponsiveness in asthma and for treating hypertension. However, the mechanism of anion exchange and its inhibition by drugs remains poorly understood. We applied cryo-electron microscopy to determine structures of pendrin from Sus scrofa in the presence of either Cl−, I−, HCO3 − or in the apo-state. The structures reveal two anion-binding sites in each protomer, and functional analyses show both sites are involved in anion exchange. The structures also show interactions between the Sulfate Transporter and Anti-Sigma factor antagonist (STAS) and transmembrane domains, and mutational studies suggest a regulatory role. We also determine the structure of pendrin in a complex with niflumic acid (NFA), which uncovers a mechanism of inhibition by competing with anion binding and impeding the structural changes necessary for anion exchange. These results reveal directions for understanding the mechanisms of anion selectivity and exchange and their regulations by the STAS domain. This work also establishes a foundation for analyzing the pathophysiology of mutations associated with Pendred syndrome.https://doi.org/10.1038/s41467-023-44612-1
spellingShingle Lie Wang
Anthony Hoang
Eva Gil-Iturbe
Arthur Laganowsky
Matthias Quick
Ming Zhou
Mechanism of anion exchange and small-molecule inhibition of pendrin
Nature Communications
title Mechanism of anion exchange and small-molecule inhibition of pendrin
title_full Mechanism of anion exchange and small-molecule inhibition of pendrin
title_fullStr Mechanism of anion exchange and small-molecule inhibition of pendrin
title_full_unstemmed Mechanism of anion exchange and small-molecule inhibition of pendrin
title_short Mechanism of anion exchange and small-molecule inhibition of pendrin
title_sort mechanism of anion exchange and small molecule inhibition of pendrin
url https://doi.org/10.1038/s41467-023-44612-1
work_keys_str_mv AT liewang mechanismofanionexchangeandsmallmoleculeinhibitionofpendrin
AT anthonyhoang mechanismofanionexchangeandsmallmoleculeinhibitionofpendrin
AT evagiliturbe mechanismofanionexchangeandsmallmoleculeinhibitionofpendrin
AT arthurlaganowsky mechanismofanionexchangeandsmallmoleculeinhibitionofpendrin
AT matthiasquick mechanismofanionexchangeandsmallmoleculeinhibitionofpendrin
AT mingzhou mechanismofanionexchangeandsmallmoleculeinhibitionofpendrin