RT Journal Article
SR Electronic
T1 Structural basis for stereospecific inhibition of ASCT2 from rational design
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.05.29.124305
DO 10.1101/2020.05.29.124305
A1 Rachel-Ann A. Garibsingh
A1 Elias Ndaru
A1 Alisa A. Garaeva
A1 Massimiliano Bonomi
A1 Dirk J. Slotboom
A1 Cristina Paulino
A1 Christof Grewer
A1 Avner Schlessinger
YR 2020
UL http://biorxiv.org/content/early/2020/05/31/2020.05.29.124305.abstract
AB ASCT2 (SLC1A5) is a sodium-dependent neutral amino acid transporter that controls amino acid homeostasis in peripheral tissues. ASCT2 is upregulated in cancer, where it modulates intracellular glutamine levels, fueling cell proliferation. Nutrient deprivation via ASCT2 inhibition provides an emerging strategy for cancer therapy. Here, guided by a homology model of ASCT2 in an outward-facing conformation, we rationally designed novel inhibitors exploiting stereospecific pockets in the substrate binding site. A cryo-EM structure of ASCT2 in complex with inhibitor (Lc-BPE) validated our predictions and was subsequently refined based on computational analysis. The final structures, combined with MD simulations, show that the inhibitor samples multiple conformations in the ASCT2 binding site. Our results demonstrate the utility of combining computational modeling and cryo-EM for SLC ligand discovery, and a viable strategy for structure determination of druggable conformational states for challenging membrane protein targets.Competing Interest StatementAvner Schlessinger is the Co-Founder of AIchemy.