6yox
14-3-3 sigma with RelA/p65 binding site pS45 and covalently bound TCF521-027
Structural highlights
FunctionTF65_HUMAN NF-kappa-B is a pleiotropic transcription factor present in almost all cell types and is the endpoint of a series of signal transduction events that are initiated by a vast array of stimuli related to many biological processes such as inflammation, immunity, differentiation, cell growth, tumorigenesis and apoptosis. NF-kappa-B is a homo- or heterodimeric complex formed by the Rel-like domain-containing proteins RELA/p65, RELB, NFKB1/p105, NFKB1/p50, REL and NFKB2/p52 and the heterodimeric p65-p50 complex appears to be most abundant one. The dimers bind at kappa-B sites in the DNA of their target genes and the individual dimers have distinct preferences for different kappa-B sites that they can bind with distinguishable affinity and specificity. Different dimer combinations act as transcriptional activators or repressors, respectively. NF-kappa-B is controlled by various mechanisms of post-translational modification and subcellular compartmentalization as well as by interactions with other cofactors or corepressors. NF-kappa-B complexes are held in the cytoplasm in an inactive state complexed with members of the NF-kappa-B inhibitor (I-kappa-B) family. In a conventional activation pathway, I-kappa-B is phosphorylated by I-kappa-B kinases (IKKs) in response to different activators, subsequently degraded thus liberating the active NF-kappa-B complex which translocates to the nucleus. NF-kappa-B heterodimeric p65-p50 and p65-c-Rel complexes are transcriptional activators. The NF-kappa-B p65-p65 complex appears to be involved in invasin-mediated activation of IL-8 expression. The inhibitory effect of I-kappa-B upon NF-kappa-B the cytoplasm is exerted primarily through the interaction with p65. p65 shows a weak DNA-binding site which could contribute directly to DNA binding in the NF-kappa-B complex. Associates with chromatin at the NF-kappa-B promoter region via association with DDX1.[1] [2] [3] [4] [5] [6] Publication Abstract from PubMedSmall-molecule stabilization of protein-protein interactions (PPI) is a promising concept in drug discovery, however the question how to identify or design chemical starting points in a 'bottom-up' approach is largely unanswered. Here we report a novel concept for identifying initial chemical matter for PPI stabilization based on covalent imine forming fragments. The imine bond offers a covalent anchor for site-directed fragment targeting, whereas its transient nature allows an efficient structure activity relationship analysis. This bond enables fragment identification and optimisation using protein crystallography. We report novel fragments which bind specifically to a lysine at the PPI interface of the p65 subunit-derived peptide of NF-kappaB with the adapter protein 14-3-3. Those fragments that subsequently establish contacts with the p65-derived peptide, rather than with 14-3-3, efficiently stabilize the 14-3-3/p65 complex and offer novel starting points for molecular glues. Fragment Based Protein-Protein Interaction Stabilizers via Imine-Based Tethering.,Ottmann C, Wolter M, Valenti D, Cossar PJ, Levy LM, Hristeva S, Genski T, Hoffmann T, Brunsveld L, Tzalis D Angew Chem Int Ed Engl. 2020 Aug 20. doi: 10.1002/anie.202008585. PMID:32816380[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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