{"title":"Cryo-EM structures of the zinc transporters ZnT3 and ZnT4 provide insights into their transport mechanisms.","authors":"Hanako Ishida, Riri Yo, Zhikuan Zhang, Toshiyuki Shimizu, Umeharu Ohto","doi":"10.1002/1873-3468.15047","DOIUrl":null,"url":null,"abstract":"<p><p>Zinc transporters (ZnTs) act as H<sup>+</sup>/Zn<sup>2+</sup> antiporters, crucial for zinc homeostasis. Brain-specific ZnT3 expressed in synaptic vesicles transports Zn<sup>2+</sup> from the cytosol into vesicles and is essential for neurotransmission, with ZnT3 dysfunction associated with neurological disorders. Ubiquitously expressed ZnT4 localized to lysosomes facilitates the Zn<sup>2+</sup> efflux from the cytosol to lysosomes, mitigating the cell injury risk. Despite their importance, the structures and Zn<sup>2+</sup> transport mechanisms remain unclear. We characterized the three-dimensional structures of human ZnT3 (inward-facing) and ZnT4 (outward-facing) using cryo-electron microscopy. By combining these structures, we assessed the conformational changes that could occur within the transmembrane domain during Zn<sup>2+</sup> transport. Our results provide a structural basis for a more comprehensive understanding of the H<sup>+</sup>/Zn<sup>2+</sup> exchange mechanisms exhibited by ZnTs.</p>","PeriodicalId":12142,"journal":{"name":"FEBS Letters","volume":null,"pages":null},"PeriodicalIF":3.5000,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"FEBS Letters","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1002/1873-3468.15047","RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"Biochemistry, Genetics and Molecular Biology","Score":null,"Total":0}
引用次数: 0
Abstract
Zinc transporters (ZnTs) act as H+/Zn2+ antiporters, crucial for zinc homeostasis. Brain-specific ZnT3 expressed in synaptic vesicles transports Zn2+ from the cytosol into vesicles and is essential for neurotransmission, with ZnT3 dysfunction associated with neurological disorders. Ubiquitously expressed ZnT4 localized to lysosomes facilitates the Zn2+ efflux from the cytosol to lysosomes, mitigating the cell injury risk. Despite their importance, the structures and Zn2+ transport mechanisms remain unclear. We characterized the three-dimensional structures of human ZnT3 (inward-facing) and ZnT4 (outward-facing) using cryo-electron microscopy. By combining these structures, we assessed the conformational changes that could occur within the transmembrane domain during Zn2+ transport. Our results provide a structural basis for a more comprehensive understanding of the H+/Zn2+ exchange mechanisms exhibited by ZnTs.
期刊介绍:
FEBS Letters is one of the world''s leading journals in molecular biology and is renowned both for its quality of content and speed of production. Bringing together the most important developments in the molecular biosciences, FEBS Letters provides an international forum for Minireviews, Research Letters and Hypotheses that merit urgent publication.