Chimeric 14-3-3 Proteins for Unraveling Interactions with Intrinsically Disordered Partners
Affiliations
In eukaryotes, several "hub" proteins integrate signals from different interacting partners that bind through intrinsically disordered regions. The 14-3-3 protein hub, which plays wide-ranging roles in cellular processes, has been linked to numerous human disorders and is a promising target for therapeutic intervention. Partner proteins usually bind via insertion of a phosphopeptide into an amphipathic groove of 14-3-3. Structural plasticity in the groove generates promiscuity allowing accommodation of hundreds of different partners. So far, accurate structural information has been derived for only a few 14-3-3 complexes with phosphopeptide-containing proteins and a variety of complexes with short synthetic peptides. To further advance structural studies, here we propose a novel approach based on fusing 14-3-3 proteins with the target partner peptide sequences. Such chimeric proteins are easy to design, express, purify and crystallize. Peptide attachment to the C terminus of 14-3-3 via an optimal linker allows its phosphorylation by protein kinase A during bacterial co-expression and subsequent binding at the amphipathic groove. Crystal structures of 14-3-3 chimeras with three different peptides provide detailed structural information on peptide-14-3-3 interactions. This simple but powerful approach, employing chimeric proteins, can reinvigorate studies of 14-3-3/phosphoprotein assemblies, including those with challenging low-affinity partners, and may facilitate the design of novel biosensors.
Wu Q, van den Wildenberg S, Brzoskowski J, van den Oetelaar M, Verhoef C, Genet S Chem Sci. 2025; 16(8):3523-3535.
PMID: 39850253 PMC: 11752056. DOI: 10.1039/d4sc07419j.
Fragment-Based Interrogation of the 14-3-3/TAZ Protein-Protein Interaction.
Andlovic B, Valenti D, Centorrino F, Picarazzi F, Hristeva S, Hiltmann M Biochemistry. 2024; 63(17):2196-2206.
PMID: 39172504 PMC: 11375770. DOI: 10.1021/acs.biochem.4c00248.
Egbert C, Warr L, Pennington K, Thornton M, Vaughan A, Ashworth S J Mol Biol. 2022; 435(2):167890.
PMID: 36402225 PMC: 10099770. DOI: 10.1016/j.jmb.2022.167890.
Williams D, Thorn D, Dobson C, Meehan S, Jackson S, Woodcock J Molecules. 2021; 26(20).
PMID: 34684701 PMC: 8538830. DOI: 10.3390/molecules26206120.
Hierarchized phosphotarget binding by the seven human 14-3-3 isoforms.
Gogl G, Tugaeva K, Eberling P, Kostmann C, Trave G, Sluchanko N Nat Commun. 2021; 12(1):1677.
PMID: 33723253 PMC: 7961048. DOI: 10.1038/s41467-021-21908-8.