Regulation of ADP-ribosyltransferase activity by ART domain dimerization in PARP15.
Ebenwaldner, C., Garcia Saura, A.G., Ekstrom, S., Bernfur, K., Moche, M., Logan, D.T., Cohen, M.S., Schuler, H.(2025) Nat Commun 16: 9567-9567
- PubMed: 41162413 
- DOI: https://doi.org/10.1038/s41467-025-65315-9
- Primary Citation of Related Structures:  
9IFV - PubMed Abstract: 
PARP15 is a mono-ADP-ribosyltransferase that targets an unknown set of proteins as well as RNA. Its evolutionary relationship with PARP14 suggests roles in antiviral defence; its localization to stress granules points to functions in the regulation of translation. Here we show that the transferase domain of PARP15 dimerizes in solution; the formation of dimers is a prerequisite for catalytic activity and monomeric mutant variants of the domain are inactive. In cells, dimer-disrupting mutations abrogate catalytic activity and alter the subcellular localization of the full-length protein. Using biophysical methods, including X-ray crystallography and HDX-MS, we provide evidence for a regulatory mechanism by which dimerization enables correct target engagement rather than NAD + co-substrate binding, and by which the two protomers of the dimer operate independently of one another. Together, our results uncover a regulatory mechanism in a PARP family enzyme.
- Division of Biochemistry and Structural Biology, Department of Chemistry, Lund University, Lund, Sweden.
Organizational Affiliation: 
















