Download MendeleyStructures of ATP-binding cassette transporter ABCC1 reveal the molecular basis of cyclic dinucleotide cGAMP export.
Shinde, O., Boyer, J.A., Cambier, S., VanPortfliet, J.J., Sui, X., Yadav, G.P., Viverette, E.G., Borgnia, M.J., West, A.P., Zhang, Q., Stetson, D.B., Li, P.(2025) Immunity 58: 59
- PubMed: 39765229
- DOI: https://doi.org/10.1016/j.immuni.2024.12.002
- Primary Citation of Related Structures:
8VT4, 8VUX, 8VVC - 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 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.
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA.
Organizational Affiliation:
