Mechanism of substrate transport and inhibition of the human LAT1-4F2hc amino acid transporter.

Autor: Yan R; Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China.; Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China., Li Y; Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100085, China., Müller J; ETH Zürich, Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, Vladimir-Prelog-Weg 1- 5/10, 8093, Zurich, Switzerland., Zhang Y; Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China.; Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China., Singer S; Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28 3012, Bern, Switzerland., Xia L; Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China.; Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China., Zhong X; Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China.; Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China., Gertsch J; Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28 3012, Bern, Switzerland., Altmann KH; ETH Zürich, Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, Vladimir-Prelog-Weg 1- 5/10, 8093, Zurich, Switzerland. karl-heinz.altmann@pharma.ethz.ch., Zhou Q; Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China. zhouqiang@westlake.edu.cn.; Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China. zhouqiang@westlake.edu.cn.
Jazyk: angličtina
Zdroj: Cell discovery [Cell Discov] 2021 Mar 23; Vol. 7 (1), pp. 16. Date of Electronic Publication: 2021 Mar 23.
DOI: 10.1038/s41421-021-00247-4
Abstrakt: LAT1 (SLC7A5) is one of the representative light chain proteins of heteromeric amino acid transporters, forming a heterodimer with its heavy chain partner 4F2hc (SLC3A2). LAT1 is overexpressed in many types of tumors and mediates the transfer of drugs and hormones across the blood-brain barrier. Thus, LAT1 is considered as a drug target for cancer treatment and may be exploited for drug delivery into the brain. Here, we synthesized three potent inhibitors of human LAT1, which inhibit transport of leucine with IC 50 values between 100 and 250 nM, and solved the cryo-EM structures of the corresponding LAT1-4F2hc complexes with these inhibitors bound at resolution of up to 2.7 or 2.8 Å. The protein assumes an outward-facing occluded conformation, with the inhibitors bound in the classical substrate binding pocket, but with their tails wedged between the substrate binding site and TM10 of LAT1. We also solved the complex structure of LAT1-4F2hc with 3,5-diiodo-L-tyrosine (Diiodo-Tyr) at 3.4 Å overall resolution, which revealed a different inhibition mechanism and might represent an intermediate conformation between the outward-facing occluded state mentioned above and the outward-open state. To our knowledge, this is the first time that the outward-facing conformation is revealed for the HAT family. Our results unveil more important insights into the working mechanisms of HATs and provide a structural basis for future drug design.
Databáze: MEDLINE
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