28uw
Ternary structure of 14-3-3sigma, interaction cassette phosphopeptide, and Fusicoccin-A
Structural highlights
Function1433S_HUMAN Adapter protein implicated in the regulation of a large spectrum of both general and specialized signaling pathways. Binds to a large number of partners, usually by recognition of a phosphoserine or phosphothreonine motif. Binding generally results in the modulation of the activity of the binding partner. When bound to KRT17, regulates protein synthesis and epithelial cell growth by stimulating Akt/mTOR pathway (By similarity). p53-regulated inhibitor of G2/M progression. Publication Abstract from PubMedThe tumor suppressor p53 is regulated by phosphorylation-dependent protein-protein interactions, including via binding to 14-3-3 adaptor proteins, which can tune p53 activity. Molecular glue (MG)-induced stabilization of 14-3-3/client interactions offers an attractive strategy to probe such networks, but cellular engagement is often constrained by context-dependent phosphorylation and interaction occupancy. Here, we engineered phosphorylation- and MG-dependent 14-3-3 interaction cassettes (IC1 and IC2) and fused them to p53 to promote recruitment of endogenous 14-3-3 proteins in human cells. Biochemical characterization establishes high-affinity binding of the phosphorylated cassettes to 14-3-3 and enhanced in vitro stabilization by the 14-3-3 molecular glue 3'-deacetylated fusicoccin-A (FC-A). In HEK293T cells, Flag-p53-IC1 and Flag-p53-IC2 co-immunoprecipitated native 14-3-3 proteins. Mutation of the cassette's phospho-accepting serine to alanine abolished binding, confirming phosphorylation dependent recruitment. Transcriptomic profiling of transiently transfected cells reveals cassette-dependent remodeling of a p53-associated gene expression landscape. Together, these results establish a modular, MG- and phosphorylation-dependent platform for engaging 14-3-3 in a p53 context and for evaluating how chemical stabilization translates from biochemical interaction control to cellular pathway-level readouts. Molecular Glue and Phosphorylation-Dependent 14-3-3 Recruitment to p53 with an Engineered Interaction Cassette.,Munoz-Lasso DC, Ni Y, Weber G, Eduati F, Beijersbergen RL, Ottmann C, Brunsveld L ACS Chem Biol. 2026 Aug 21. doi: 10.1021/acschembio.6c00482. PMID:42631642[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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