Structural Basis for the Recognition of GPRC5D by Talquetamab, a Bispecific Antibody for Multiple Myeloma.
Jeong, J., Park, J., Young Mo, G., Shin, J., Cho, Y.(2024) J Mol Biology 436: 168748-168748
- PubMed: 39181182 
- DOI: https://doi.org/10.1016/j.jmb.2024.168748
- Primary Citation of Related Structures:  
9IMA - PubMed Abstract: 
Multiple myeloma (MM) is a complex hematological malignancy characterized by abnormal antibody production from plasma cells. Despite advances in the treatment, many patients experience disease relapse or become refractory to treatment. G-protein-coupled receptor class C group 5 member D (GPRC5D), an orphan GPCR predominantly expressed in MM cells, is emerging as a promising target for MM immunotherapy. Talquetamab, a Food and Drug Administration-approved T-cell-directing bispecific antibody developed for treatment of MM, targets GPRC5D. Here, we elucidate the structure of GPRC5D complexed with the Fab fragment of talquetamab, using cryo-electron microscopy, providing the basis for recognition of GPRC5D by the bispecific antibody. GPRC5D forms a symmetric homodimer with the interface between transmembrane helix (TM) 4 of one protomer and TM4/5 of the other protomer. A single talquetamab Fab interacts with the GPRC5D dimer with its orientation toward the dimer interface. All six complementarity-determining regions of talquetamab engage with extracellular loops and TM3/5/7. In particular, the side-chain of an arginine residue from the antibody penetrates into a shallow pocket on the extracellular surface of GPRC5D. The structure offers insights for optimizing antibody design against GPRC5D for relapsed or refractory MM therapy.
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Kyungbook 37673, South Korea.
Organizational Affiliation: 


















