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Title | Structures of ATP-binding cassette transporter ABCC1 reveal the molecular basis of cyclic dinucleotide cGAMP export. |
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Journal, issue, pages | Immunity, Vol. 58, Issue 1, Page 59-73.e5, Year 2025 |
Publish date | Jan 14, 2025 |
![]() | Omkar Shinde / Joshua A Boyer / Stephanie Cambier / Jordyn J VanPortfliet / Xuewu Sui / Gaya P Yadav / Elizabeth G Viverette / Mario J Borgnia / A Phillip West / Qi Zhang / Daniel B Stetson / Pingwei Li / ![]() |
PubMed Abstract | Cyclic nucleotide GMP-AMP (cGAMP) plays a critical role in mediating the innate immune response through the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway. Recent ...Cyclic nucleotide GMP-AMP (cGAMP) plays a critical role in mediating the innate immune response through the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway. Recent studies showed that ATP-binding cassette subfamily C member 1 (ABCC1) is a cGAMP exporter. The exported cGAMP can be imported into uninfected cells to stimulate a STING-mediated innate immune response. However, the molecular basis of cGAMP export mediated by ABCC1 remains unclear. Here, we report the cryoelectron microscopy (cryo-EM) structures of human ABCC1 in a ligand-free state and a cGAMP-bound state. These structures reveal that ABCC1 forms a homodimer via its N-terminal transmembrane domain. The ligand-bound structure shows that cGAMP is recognized by a positively charged pocket. Mutagenesis and functional studies confirmed the roles of the ligand-binding pocket in cGAMP recognition and export. This study provides insights into the structure and function of ABCC1 as a cGAMP exporter and lays a foundation for future research targeting ABCC1 in infection and anti-cancer immunity. |
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Methods | EM (single particle) |
Resolution | 3.54 - 4.32 Å |
Structure data | EMDB-43518, PDB-8vt4: EMDB-43543, PDB-8vux: EMDB-43550, PDB-8vvc: |
Chemicals | ![]() ChemComp-Y01: ![]() ChemComp-1SY: |
Source |
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![]() | MEMBRANE PROTEIN / Organic anion exporter / ATPase-dependent export / homodimer / multidrug-resistant protein / cGAMP exporter / ABC transporter |