Structure of the human dopamine transporter and mechanisms of inhibition

• 成果类型: Article
• 署名作者: Srivastava, Dushyant Kumar; Navratna, Vikas; Tosh, Dilip K.; Chinn, Audrey; Sk, Md Fulbabu; Tajkhorshid, Emad; Jacobson, Kenneth A.; Gouaux, Eric
• 署名单位: Oregon Health & Science University; National Institutes of Health (NIH) - USA; NIH National Institute of Diabetes & Digestive & Kidney Diseases (NIDDK); University of Illinois System; University of Illinois Urbana-Champaign; University of Illinois System; University of Illinois Urbana-Champaign; University of Illinois System; University of Illinois Urbana-Champaign; Oregon Health & Science University; Howard Hughes Medical Institute; University of Michigan System; University of Michigan
• 刊物名称: Nature
• ISSN/ISSBN: 0028-6929
• DOI: 10.1038/s41586-024-07739-9
• 发表日期: 2024-08-15
• 页码: 672-+
• 关键词: x-ray structures; molecular-dynamics; cryo-em; membrane-transport; endogenous zinc; n-glycosylation; neurotransmitter; expression; software; proteins

摘要

The neurotransmitter dopamine has central roles in mood, appetite, arousal and movement(1). Despite its importance in brain physiology and function, and as a target for illicit and therapeutic drugs, the human dopamine transporter (hDAT) and mechanisms by which it is inhibited by small molecules and Zn2+ are without a high-resolution structural context. Here we determine the structure of hDAT in a tripartite complex with the competitive inhibitor and cocaine analogue, (-)-2-beta-carbomethoxy-3-beta-(4-fluorophenyl)tropane(2) (beta-CFT), the non-competitive inhibitor MRS7292(3) and Zn2+ (ref. (4)). We show how beta-CFT occupies the central site, approximately halfway across the membrane, stabilizing the transporter in an outward-open conformation. MRS7292 binds to a structurally uncharacterized allosteric site, adjacent to the extracellular vestibule, sequestered underneath the extracellular loop 4 (EL4) and adjacent to transmembrane helix 1b (TM1b), acting as a wedge, precluding movement of TM1b and closure of the extracellular gate. A Zn2+ ion further stabilizes the outward-facing conformation by coupling EL4 to EL2, TM7 and TM8, thus providing specific insights into how Zn2+ restrains the movement of EL4 relative to EL2 and inhibits transport activity.