Correction for ‘Dynamic conformational equilibria in the active states of KRAS and NRAS’ by Enrico Rennella et al. , RSC Chem. Biol. , 2025, 6 , 106–118, https://doi.org/10.1039/D4CB00233D.

The Werner Syndrome RecQ helicase (WRN) is a synthetic lethal target of interest for the treatment of cancers with microsatellite instability (MSI). Different hit finding approaches were initially tested. The identification of WRN inhibitors proved challenging due to a high propensity for artefacts via protein interference, i. e., hits inhibiting WRN enzymatic activities through multiple, unspecific mechanisms. Previously published WRN Helicase inhibitors (ML216, NSC19630 or NSC617145) were characterized in an extensive set of biochemical and biophysical assays and could be ruled out as specific WRN helicase probes. More innovative screening strategies need to be developed for successful drug discovery of non-covalent WRN helicase inhibitors. One of the major hurdles in targeting WRN helicase is to overcome the challenge of false positives in screening due to the high propensity of WRN to protein interferences. Biochemical and biophysical fingerprints of hits allow to triage the hits and highlight the artefacts, including compounds (ML216 and NSC617145) wrongly considered as specific WRN probes. image

Supplementary Figure 2 from Modulation of drug resistance by artificial transcription factors

Supplementary Data from Potent and Selective Inhibition of Polycythemia by the Quinoxaline JAK2 Inhibitor NVP-BSK805

PDF - 92K, NVP-BYL719 does not inhibit mTOR and PIKKs involved in DNA damage-repair processes. A. TSC1 -/- MEFs cells were grown in a 96-well format and treated for 1 h with increased concentrations of RAD001 or NVP-BYL719 (from 0.5 nmol/L to 10 ?mol/L in 1 third dilution steps) and immediately fixed. S235/236P-RPS6 levels were measured and IC50 determined with the Excel module XLfit. Background (no primary Ab incubated); BL, Baseline. B: TSC1 -/- MEFs cells were treated with increasing concentrations of NVP-BYL719 as indicated or RAD001 at 500 nmol/L or an equivalent DMSO concentration for 30 minutes. Levels of S235/236P-RPS6 and total RPS6 in protein- normalized lysates were detected by Western blot analyzis using an activation-state specific antibody, followed by incubation with species- specific HRP-labeled secondary antibody and signal development by ECL. C: 24 h post seeding, A549 cells were treated at the same time with Actinomycin D (Act D) at a concentration of 5 ?mol/L (an agent used to induce DNA damage), and with increasing concentrations of NVP-BYL719 as indicated or with the vehicle control (DMSO) for 1 h. Levels of S15P-p53 and tubulin in protein-normalized lysates were detected by Western blot analysis using an activation-state specific antibody, followed by incubation with species- specific HRP-labeled secondary antibody and signal development by ECL. D: 24 h post seeding, U2OS cells were pre-treated for 1 h with increased concentrations of NVP-BYL719 or KU55933 a specific small molecular mass inhibitor of ATM (Supplementary reference 1) at a concentration of 10 ?mol/L or with the vehicle control (DMSO). The cells were then irradiated with 15 Gy and re-incubated at 37 degrees C for 1 h and then lysed. Levels of S1981P-ATM in protein- normalized lysates were detected by Western blot analysis using an activation-state specific antibody, followed by incubation with species- specific HRP-labeled secondary antibody and signal development by ECL.

Supplementary Figure 1 from Modulation of drug resistance by artificial transcription factors

Supplementary Figure 4 from Modulation of drug resistance by artificial transcription factors

The yes-associated protein (YAP) regulates the transcriptional activity of the TEAD transcription factors that are key in the control of organ morphogenesis. YAP interacts with TEAD via three secondary structure elements: a β-strand, an α-helix, and an Ω-loop. Earlier results have shown that the β-strand has only a marginal contribution in the YAP:TEAD interaction, but we show here that it significantly enhances the affinity of YAP for the Drosophila homolog of TEAD, scalloped (Sd). Nuclear magnetic resonance shows that the β-strand adopts a more rigid conformation once bound to Sd; pre-steady state kinetic measurements show that the YAP:Sd complex is more stable. Although the crystal structures of the YAP:TEAD and YAP:Sd complexes reveal no differences at the binding interface that could explain these results. Molecular Dynamics simulations are in line with our experimental findings regarding β-strand stability and overall binding affinity of YAP to TEAD and Sd. In particular, RMSF, correlated motion and MMGBSA analyses suggest that β-sheet fluctuations play a relevant role in YAP53-57 β-strand dissociation from TEAD4 and contribute to the lower affinity of YAP for TEAD4. Identifying a clear mechanism leading to the difference in YAP's β-strand stability proved to be challenging, pointing to the potential relevance of multiple modest structural changes or fluctuations for regulation of binding affinity.

PDF - 71K, Rat1-myr-p110alpha (blue), beta (green) or delta (red) cells were treated with increasing concentrations of NVP-BYL719 for 30 minutes. Levels of S473P-Akt in cell extracts were quantified by Reverse Phase Protein Array as described in (18) and plotted as percentage of untreated control cells. The graph illustrates n=3 independent experiments. IC50s (plus/minus) SD and IC80s (plus/minus) SD of n=3 independent experiments are reported..

PDF - 129K, Legends for Supplementary Figures 1 through 4 and Supplementary Tables 1 through 7. Supplementary Table 1. Determination of NVP-BYL719 in vitro effects on human protein kinases. Supplementary Table 2. Activity profile of NVP-BYL719 in the Invitrogen Kinase panel. Supplementary Table 3. Activity profile of NVP-BYL719 in the Ambit Kinase panel. Supplementary Table 4. NVP-BYL719 Kd (nmol/L) determination in the Ambit Kinase panel for the hits found to be inhibited >90%. Supplementary Table 5. NVP-BYL719 anti-tumor effects in diverse cancer cell line-derived xenograft models. Supplementary Table 6. CCLE cell lines responsive to NVP-BYL719. Supplementary Table 7 Anti-tumor effect of NVP-BYL719 in patient-derived xenograft models carrying PIK3CA genetic alterations.

PDF - 60K, Linear correlation observed between tumor growth inhibition (% T/C) or tumor regression and the fraction of time over the in vivo S473P-Akt IC80 in different cancer cell line-derived tumor xenografts implanted in nude mice (represented as dots) and nude rats (represented as triangles) following NVP-BYL719 treatment (R2=0.77, p<0.001, n=27).

Supplementary Figure 3 from Modulation of drug resistance by artificial transcription factors

PDF - 37K, NVP-BYL719 was tested at 10 different concentrations (from 0.5 nmol/L to 10 μmol/L in 1 third dilution steps) against CLK2 (A) and LRRK2 (B). SelectScreenTM Kinase Profiling Service uses XLfit from IDBS to determine the IC50 values (IC50 CLK2=621 nmol/L; IC50 LRRK2=3'220 nmol/L). The dose response curve is curve fit to model number 205 (sigmoidal dose-response model).

The TEAD transcription factors are the most downstream elements of the Hippo pathway. Their transcriptional activity is modulated by different regulator proteins and by the palmitoylation/myristoylation of a specific cysteine residue. In this report, we show that a conserved lysine present in these transcription factors can also be acylated, probably following the intramolecular transfer of the acyl moiety from the cysteine. Using Scalloped (Sd), the Drosophila homolog of human TEAD, as a model, we designed a mutant protein (Glu352GlnSd) that is predominantly acylated on the lysine (Lys350Sd). This protein binds in vitro to the three Sd regulators-Yki, Vg and Tgi-with a similar affinity as the wild type Sd, but it has a significantly higher thermal stability than Sd acylated on the cysteine. This mutant was also introduced in the endogenous locus of the sd gene in Drosophila using CRISPR/Cas9. Homozygous mutants reach adulthood, do not present obvious morphological defects and the mutant protein has both the same level of expression and localization as wild type Sd. This reveals that this mutant protein is both functional and able to control cell growth in a similar fashion as wild type Sd. Therefore, enhancing the lysine acylation of Sd has no detrimental effect on the Hippo pathway. However, we did observe a slight but significant increase of wing size in flies homozygous for the mutant protein suggesting that a higher acylation of the lysine affects the activity of the Hippo pathway. Altogether, our findings indicate that TEAD/Sd can be acylated either on a cysteine or on a lysine, and suggest that these two different forms may have similar properties in cells.

The transcription factor PAX8 is critical for the development of the thyroid and urogenital system. Comprehensive genomic screens furthermore indicate an additional oncogenic role for PAX8 in renal and ovarian cancers. While a plethora of PAX8-regulated genes in different contexts have been proposed, we still lack a mechanistic understanding of how PAX8 engages molecular complexes to drive disease-relevant oncogenic transcriptional programs. Here we show that protein isoforms originating from the MECOM locus form a complex with PAX8. These include MDS1-EVI1 (also called PRDM3) for which we map its interaction with PAX8 in vitro and in vivo. We show that PAX8 binds a large number of genomic sites and forms transcriptional hubs. At a subset of these, PAX8 together with PRDM3 regulates a specific gene expression module involved in adhesion and extracellular matrix. This gene module correlates with PAX8 and MECOM expression in large scale profiling of cell lines, patient-derived xenografts (PDXs) and clinical cases and stratifies gynecological cancer cases with worse prognosis. PRDM3 is amplified in ovarian cancers and we show that the MECOM locus and PAX8 sustain in vivo tumor growth, further supporting that the identified function of the MECOM locus underlies PAX8-driven oncogenic functions in ovarian cancer.

The TEAD (Sd in drosophila) transcription factors are essential for the Hippo pathway. Human VGLL4 and drosophila Tgi bind to TEAD/Sd via two distinct binding sites. These two regions are separated by few amino acids in VGLL4 but they are very distant from each other in Tgi. This difference prompted us to study whether it influences the interaction with TEAD4/Sd. We show that the full-length VGLL4/Tgi proteins behave as intrinsically disordered proteins. They have a similar affinity for TEAD4/Sd revealing that the length of the region between the two binding sites has little effect on the interaction. One of their two binding sites (high-affinity site) binds to TEAD4/Sd 100 times more tightly than to the other site, and size exclusion chromatography experiments reveal that VGLL4/Tgi only form trimeric complexes with TEAD4/Sd at high protein concentrations. In solution, therefore, VGLL4/Tgi may predominantly interact with TEAD4/Sd via their high-affinity site to create dimeric complexes. In contrast, when TEAD4/Sd molecules are immobilized on sensor chips used in Surface Plasmon Resonance experiments, one VGLL4/Tgi molecule can bind simultaneously with an enhanced affinity to two immobilized molecules. This effect, due to a local increase in protein concentration triggered by the proximity of the immobilized TEAD4/Sd molecules, suggests that in vivo VGLL4/Tgi could bind with an enhanced affinity to two nearby TEAD/Sd molecules bound to DNA. The presence of two binding sites in VGLL4/Tgi might only be required for the function of these proteins when they interact with TEAD/Sd bound to DNA.

Abstract RAS is the most frequently mutated oncogene in cancer. KRAS G12C mutations are most prevalent in lung adenocarcinoma (~13%) and colorectal adenocarcinoma (~4%), and occur less commonly in other solid tumor malignancies. First generation KRASG12C inhibitors show anti-tumor activity in early phase clinical trials. However, the emergence of resistance, mediated at least in part by RAS gene mutations that disrupt inhibitor binding and reactivation of downstream pathways, limit the duration of response. Here we report the identification of JDQ443 (NVP-JDQ443), a novel KRASG12C inhibitor which binds under the switch II loop with a novel binding mode, exploiting unique interactions with the KRASG12C protein compared to sotorasib and adagrasib. JDQ443 potently inhibits KRASG12C cellular signaling and proliferation in a mutant selective manner by irreversibly trapping the GDP-bound state of KRASG12C through formation of a covalent bond with cysteine at position 12. Consistent with its mechanism as an irreversible inhibitor, JDQ443 shows sustained target occupancy (TO) in vivo (KRASG12C TO t1/2 ~ 66 h in the MiaPaCa2 model) despite a blood half-life of ~ 2 hours, and exhibits a linear PK/PD relationship. JDQ443 has dose-dependent anti-tumor activity in mice bearing KRAS G12C mutated tumor xenografts comparable to sotorasib and adagrasib. In mouse, rat, and dog, JDQ443 is orally bioavailable, achieves exposures in a range predicted to confer anti-tumor activity, and is well-tolerated. Continuous delivery of JDQ443 using mini-pump administration demonstrates that area under the curve (AUC), rather than maximal concentration (Cmax), is the driver of efficacy. Combination of JDQ443 with the SHP2 inhibitor TNO155 further increases KRAS G12C target occupancy in vivo, enhanced pre-clinical anti-tumor activity, and delayed the emergence of resistance in xenografts. A genome-wide CRISPR screen in 5 KRAS G12C mutated lung cancer cell lines identifies novel mechanisms of resistance to the KRAS/SHP2 drug combination. Furthermore, the characterization of JDQ443 alone and in combination with TNO155 in BaF/3 pools addicted to KRAS alleles that have previously been shown to mediate resistance to adagrasib in clinical samples will be discussed. Collectively, these data show that JDQ443 is a potent, mutant-selective, covalent irreversible KRASG12C inhibitor with favorable pharmaceutical properties. A phase Ib/II clinical trial of JDQ443 alone and in combination with TNO155 in patients with advanced solid tumors harboring the KRAS G12C mutation is ongoing (NCT04699188). Citation Format: Saskia M. Brachmann, Andreas Weiss, Daniel A. Guthy, Kim Beyer, Johannes Voshol, Michel Maira, Anirudh Prahallad, Diana Graus Porta, Christian Schnell, Nils Ostermann, Andrea Vaupel, Marc Gerspacher, Catherine Leblanc, Dirk Erdmann, Dario Sterker, Grainne Kerr, Giovannoni Jerome, Victoria Head, Rowan Stringer, Ruben De Kanter, Kearns Jeff, Danielle Roman, Toni Widmer, Peter Wessels, Eloisa Jimenez Nunez, Richard Sedrani, Frederic Zecri, Francesco Hofmann, Jeff Engleman, Edwige Lorthiois, Simona Cotesta. JDQ443, a covalent irreversible inhibitor of KRAS G12C, exhibits a novel binding mode and demonstrates potent anti-tumor activity and favorable pharmacokinetic properties in preclinical models [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P124.

The Hippo pathway is an evolutionarily conserved signaling pathway that is involved in the control of organ size and development. The TEAD transcription factors are the most downstream elements of the Hippo pathway, and their transcriptional activity is regulated via the interaction with different co-regulators such as YAP. The structure of the YAP:TEAD complex shows that YAP binds to TEAD via two distinct secondary structure elements, an alpha-helix and an Omega-loop, and site-directed mutagenesis experiments revealed that the Omega-loop is the "hot spot" of this interaction. While much is known about how YAP and TEAD interact with each other, little is known about the mechanism leading to the formation of a complex between these two proteins. Here we combine site-directed mutagenesis with pre-steady-state kinetic measurements to show that the association between these proteins follows an apparent one-step binding mechanism. Furthermore, linear free energy relationships and Phi analysis suggest that binding-induced folding of the YAP alpha-helix to TEAD occurs independently of and before formation of the Omega-loop interface. Thus, the binding-induced folding of YAP appears not to conform to the concomitant formation of tertiary structure (nucleation-condensation) usually observed for coupled binding and folding reactions. Our findings demonstrate how a mechanism reminiscent of the classical framework (diffusion-collision) mechanism of protein folding may operate in disorder-to-order transitions involving intrinsically disordered proteins.

The most downstream elements of the Hippo pathway, the TEAD transcription factors, are regulated by several cofactors, such as Vg/VGLL1-3. Earlier findings on human VGLL1 and here on human VGLL3 show that these proteins interact with TEAD via a conserved amino acid motif called the TONDU domain. Surprisingly, our studies reveal that the TEAD-binding domain of Drosophila Vg and of human VGLL2 is more complex and contains an additional structural element, an Ω-loop, that contributes to TEAD binding. To explain this unexpected structural difference between proteins from the same family, we propose that, after the genome-wide duplications at the origin of vertebrates, the Ω-loop present in an ancestral VGLL gene has been lost in some VGLL variants. These findings illustrate how structural and functional constraints can guide the evolution of transcriptional cofactors to preserve their ability to compete with other cofactors for binding to transcription factors.