Enzymes of the ALDH1A subfamily of aldehyde dehydrogenases are crucial in regulating retinoic acid (RA) signaling and have received attention as potential drug targets. ALDH1A2 is the primary RA-synthesizing enzyme in mammalian... more
Enzymes of the ALDH1A subfamily of aldehyde dehydrogenases are crucial in regulating retinoic acid (RA) signaling and have received attention as potential drug targets. ALDH1A2 is the primary RA-synthesizing enzyme in mammalian spermatogenesis and is therefore considered a viable drug target for male contraceptive development. However, only a small number of ALDH1A2 inhibitors have been reported, and information on the structure of ALDH1A2 was limited to the NAD-liganded enzyme void of substrate or inhibitors. Herein, we describe the mechanism of action of structurally unrelated reversible and irreversible inhibitors of human ALDH1A2 using direct binding studies and X-ray crystallography. All inhibitors bind to the active sites of tetrameric ALDH1A2. Compound WIN18,446 covalently reacts with the side chain of the catalytic residue Cys320, resulting in a chiral adduct in ( R) configuration. The covalent adduct directly affects the neighboring NAD molecule, which assumes a contracted ...
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Protein degraders have been developed that can aide in understanding gene function. These chemicals contain complementary bifunctional components that 1) interact with specific proteins, and 2) engage an E3 ligase which leads to... more
Protein degraders have been developed that can aide in understanding gene function. These chemicals contain complementary bifunctional components that 1) interact with specific proteins, and 2) engage an E3 ligase which leads to polyubiquitination and intracellular degradation by the proteasome. Thalidomide, infamously known for its teratogenic effects, is central to this new technology since it binds cereblon (CRBN) which promiscuously recruits the DDB1/Cul4A/Rbx1 complex to trigger target destruction. Thalidomide, and especially its immunomodulatory derivatives lenalidomide and pomalidomide, induce NK and T-cell activation by degrading IKZF1 which is a transcription factor that suppresses IL-2. Currently, it is debated whether mouse cereblon has conserved function due to a single non-conserved amino acid in mouse CRBN, Ile390 (equivalent to Val388 in human CRBN). First, our work confirms that lenalidomide induces IL-2 and the ubiquitin-dependent degradation of IKZF1 only in human ...
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Casein kinase 1 alpha (CK1α) is a serine/threonine kinase with numerous functions, including regulating the Wnt/β‐catenin and p53 pathways. CK1α has a well‐established role in inhibiting the p53 tumor suppressor by binding to MDMX and... more
Casein kinase 1 alpha (CK1α) is a serine/threonine kinase with numerous functions, including regulating the Wnt/β‐catenin and p53 pathways. CK1α has a well‐established role in inhibiting the p53 tumor suppressor by binding to MDMX and stimulating MDMX‐p53 interaction. MDMX purified from cells contains near‐stoichiometric amounts of CK1α, suggesting that MDMX may in turn regulate CK1α function. We present evidence that MDMX is a potent competitive inhibitor of CK1α kinase activity (Ki = 8 nM). Depletion of MDMX increases CK1α activity and β‐catenin S45 phosphorylation, whereas ectopic MDMX expression inhibits CK1α activity and β‐catenin phosphorylation. The MDMX acidic domain and zinc finger are necessary and sufficient for binding and inhibition of CK1α. P53 binding to MDMX disrupts an intramolecular auto‐regulatory interaction and enhances its ability to inhibit CK1α. P53‐null mice expressing the MDMXW200S/W201G mutant, defective in CK1α binding, exhibit reduced Wnt/β‐catenin target gene expression and delayed tumor development. Therefore, MDMX is a physiological inhibitor of CK1α and has a role in modulating cellular response to Wnt signaling. The MDMX‐CK1α interaction may account for certain p53‐independent functions of MDMX.
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Resistance to Androgen receptor (AR) antagonists is a significant problem in the treatment of Castration resistant prostate cancers (CRPCs). Identification of the mechanisms by which CRPCs evade Androgen Deprivation Therapies (ADT) is... more
Resistance to Androgen receptor (AR) antagonists is a significant problem in the treatment of Castration resistant prostate cancers (CRPCs). Identification of the mechanisms by which CRPCs evade Androgen Deprivation Therapies (ADT) is critical to develop novel therapeutics. We uncovered that CRPCs rely on BRD4-HOXB13 epigenetic reprogramming for androgen-independent cell proliferation. Mechanistically, BRD4, a member of the BET bromodomain family epigenetically promotes HOXB13 expression. Consistently, genetic disruption or pharmacological suppression of HOXB13 mRNA and protein expression by the novel dual activity BET bromodomain-kinase inhibitors directly correlates with rapid induction of apoptosis, potent inhibition of tumor cell proliferation, inhibits cell migration and suppresses CRPC growth. Integrative analysis revealed that the BRD4-HOXB13 transcriptome comprises a proliferative gene network implicated in cell cycle progression, nucleotide metabolism and chromatin assembly...
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Analogs of N-butyl-1-deoxynojirimycin (NB-DNJ) were prepared and assayed for inhibition of ceramide-specific glucosyltransferase (CGT), non-lysosomal -glucosidase 2 (GBA2) and the lysosomal -glucosidase 1 (GBA1). Compounds 6a-6f that... more
Analogs of N-butyl-1-deoxynojirimycin (NB-DNJ) were prepared and assayed for inhibition of ceramide-specific glucosyltransferase (CGT), non-lysosomal -glucosidase 2 (GBA2) and the lysosomal -glucosidase 1 (GBA1). Compounds 6a-6f that carry sterically demanding nitrogen substituents, and compound 14, devoid of the C3 and C5 hydroxyl groups present in DNJ/NB-DGJ (N-butyl-deoxygalactojirimycin showed no inhibitory activity for CGT or GBA2. Inversion of stereochemistry at C4 of N-(n-butyl)- and N-(n-nonyl)-DGJ (compounds 25) also led to a loss of activity in these assays. The aminocyclopentitols N-(n-butyl)- (36a), N-(n-nonyl)-4-amino-5-(hydroxymethyl)cyclopentane- (36b), and N-(1-(pentyloxy)methyl)adamantan-1-yl)-1,2,3-triol (36f), were selective inhibitors of GBA1 and GBA2 that did not inhibit CGT (>1mM) with the exception of 36f, which inhibited CGT with an IC50 of 1 mM. The N-butyl analog 36a was 1000-fold selective for inhibiting GBA1 over GBA2 (Ki values of 32 nM and 3.3 μM for...
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Evaluating the engagement of a small molecule ligand with a protein target in cells provides useful information for chemical probe optimization and pharmaceutical development. While several techniques exist that can be performed in a... more
Evaluating the engagement of a small molecule ligand with a protein target in cells provides useful information for chemical probe optimization and pharmaceutical development. While several techniques exist that can be performed in a low-throughput manner, systematic evaluation of large compound libraries remains a challenge. In-cell engagement measurements are especially useful when evaluating compound classes suspected to target multiple cellular factors. In this study we used a bioluminescent resonant energy transfer assay to assess bromodomain engagement by a compound series containing bromodomain- and kinase-biasing polypharmacophores based on the known dual BRD4 bromodomain/PLK1 kinase inhibitor BI2536. With this assay, we discovered several novel agents with bromodomain-selective specificity profiles and cellular activity. Thus, this platform aids in distinguishing molecules whose cellular activity is difficult to assess due to polypharmacologic effects.
Research Interests: Organic Chemistry, Computational Biology, Biology, Transcription Factors, Medicine, and 12 moreFluorescence Resonance Energy Transfer, Humans, Drug Design, Kinase, Small Molecule, Cell cycle checkpoints, Cell Cycle Proteins, Protein Binding, Cell Survival, BRD, fluorescent dyes, and Pharmacology and pharmaceutical sciences
The p53 inhibitor MDMX is controlled by multiple stress signaling pathways. Using a proteolytic fragment release (PFR) assay, we detected an intramolecular interaction in MDMX that mechanistically mimics the interaction with p53,... more
The p53 inhibitor MDMX is controlled by multiple stress signaling pathways. Using a proteolytic fragment release (PFR) assay, we detected an intramolecular interaction in MDMX that mechanistically mimics the interaction with p53, resulting in autoinhibition of MDMX. This mimicry is mediated by a hydrophobic peptide located in a long disordered central segment of MDMX that has sequence similarity to the p53 transactivation domain. NMR spectroscopy was used to show this hydrophobic peptide interacts with the N-terminal domain of MDMX in a structurally analogous manner to p53. Mutation of two critical tryptophan residues in the hydrophobic peptide disrupted the intramolecular interaction and increased p53 binding, providing further evidence for mechanistic mimicry. The PFR assay also revealed a second intramolecular interaction between the RING domain and central region that regulates MDMX nuclear import. These results establish the importance of intramolecular interactions in MDMX reg...
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Research Interests: Biochemistry, Chemistry, Medicinal Chemistry, Biotechnology, Cancer, and 15 moreCell Biology, Medicine, Crystal structure, Humans, Ic, Mitogen Activated Protein Kinase, Kinase, Mammary gland, Medicinal, Binding Site, Molecular Structure, Breast Cancer Cells, Adenosine Triphosphate, ATP binding site, and binding sites
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We report the first set of small molecule co-crystal structures with the bromodomain of BPTF and describe several new leads for chemical probe development.
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Upon binding to thalidomide and other immunomodulatory drugs, the E3 ligase substrate receptor cereblon (CRBN) promotes proteasomal destruction by engaging the DDB1-CUL4A-Roc1-RBX1 E3-ubiquitin ligase in human cells but not in mouse cells... more
Upon binding to thalidomide and other immunomodulatory drugs, the E3 ligase substrate receptor cereblon (CRBN) promotes proteasomal destruction by engaging the DDB1-CUL4A-Roc1-RBX1 E3-ubiquitin ligase in human cells but not in mouse cells suggesting that sequence variations in CRBN may cause its inactivation. Therapeutically, CRBN engagers have the potential for broad applications in cancer and immune therapy by specifically reducing protein expression through targeted ubiquitin-mediated degradation. To examine the effects of defined sequence changes on CRBNs activity, we performed a comprehensive study using complementary theoretical, biophysical, and biological assays aimed at understanding CRBNs non-primate sequence variations. With a series of recombinant thalidomide-binding domain (TBD) proteins, we show that CRBN sequence variants retain their drug binding properties to both classical immunomodulatory drugs and to dBET1, a chemical compound and targeting ligand designed to deg...
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Inhibition of the WEE1 tyrosine kinase enhances anticancer chemotherapy efficacy. Accordingly, the WEE1 inhibitor AZD1775 (previously MK-1775) is currently under evaluation in clinical trials for cancer in combination with chemotherapy.... more
Inhibition of the WEE1 tyrosine kinase enhances anticancer chemotherapy efficacy. Accordingly, the WEE1 inhibitor AZD1775 (previously MK-1775) is currently under evaluation in clinical trials for cancer in combination with chemotherapy. AZD1775 has been reported to display high selectivity and is therefore used in many studies as a probe to interrogate WEE1 biology. However, AZD1775 also exhibits anticancer activity as a single agent although the underlying mechanism is not fully understood. Using a chemical proteomics approach, we here describe a proteome-wide survey of AZD1775 targets in lung cancer cells and identify several previously unknown targets in addition to WEE1. In particular, we observed polo-like kinase 1 (PLK1) as a new target of AZD1775. Importantly, in vitro kinase assays showed PLK1 and WEE1 to be inhibited by AZD1775 with similar potency. Subsequent loss-of-function experiments using RNAi for WEE1 and PLK1 suggested that targeting PLK1 enhances the pro-apoptotic ...
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Meiotic recombination ensures faithful segregation of homologous chromosomes during meiosis and generates genetic diversity in gametes. MEIOB, a meiosis-specific ssDNA-binding homologue of RPA1, is essential for meiotic recombination.... more
Meiotic recombination ensures faithful segregation of homologous chromosomes during meiosis and generates genetic diversity in gametes. MEIOB, a meiosis-specific ssDNA-binding homologue of RPA1, is essential for meiotic recombination. Here we investigated the molecular mechanisms of MEIOB by characterizing its binding partners SPATA22 and RPA. We find that MEIOB and SPATA22 form an obligate complex and contain defined interaction domains. The interaction between these two proteins is unusual in that nearly any deletion in the binding domains abolishes the interaction. Strikingly, a single residue D383 in MEIOB is indispensable for the interaction. The MEIOB/SPATA22 complex interacts with the RPA heterotrimeric complex in a collaborative manner. Furthermore, MEIOB and SPATA22 are recruited to induced DNA double-strand breaks (DSBs) together but not alone. These results demonstrate the cooperative property of the MEIOB-SPATA22 complex in its interaction with RPA and recruitment to DSBs.
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Chemical inhibition of epigenetic regulatory proteins BrdT and Brd4 is emerging as a promising therapeutic strategy in contraception, cancer, and heart disease. We report an easily synthesized dihydropyridopyrmidine pan-BET inhibitor... more
Chemical inhibition of epigenetic regulatory proteins BrdT and Brd4 is emerging as a promising therapeutic strategy in contraception, cancer, and heart disease. We report an easily synthesized dihydropyridopyrmidine pan-BET inhibitor scaffold, which was uncovered via a virtual screen followed by testing in a fluorescence anisotropy assay. Dihydropyridpyimidine 3 was subjected to further characterization and is highly selective for the BET family of bromodomains. Structure-activity relationship data and ligand deconstruction highlight the importance of the substitution of the uracil moiety for potency and selectivity. Compound 3 was also cocrystallized with Brd4 for determining the ligand binding pose and rationalizing subsequent structure-activity data. An additional series of dihydropyridopyrimidines was synthesized to exploit the proximity of a channel near the ZA loop of Brd4, leading to compounds with submicromolar affinity and cellular target engagement. Given these findings, n...
Research Interests: Organic Chemistry, Medicinal Chemistry, Magnetic Resonance Spectroscopy, Transcription Factors, Macromolecular X-Ray Crystallography, and 9 moreCell line, Humans, Computer User Interface Design, Protein Domains, Fluorescence polarization, Structure activity Relationship, Fluorometry, binding sites, and Pharmacology and pharmaceutical sciences
Synergistic action of kinase and BET bromodomain inhibitors in cell killing has been reported for a variety of cancers. Using the chemical scaffold of the JAK2 inhibitor TG101348 we developed and characterized single agents which potently... more
Synergistic action of kinase and BET bromodomain inhibitors in cell killing has been reported for a variety of cancers. Using the chemical scaffold of the JAK2 inhibitor TG101348 we developed and characterized single agents which potently and simultaneously inhibit BRD4 and a specific set of oncogenic tyrosine kinases including JAK2, FLT3, RET, and ROS1. Lead compounds showed on-target inhibition in several blood cancer cell lines and were highly efficacious at inhibiting the growth of hematopoietic progenitor cells from myeloproliferative neoplasm (MPN) patients. Screening across 931 cancer cell lines revealed differential growth inhibitory potential with highest activity against bone and blood cancers, and greatly enhanced activity over the single BET inhibitor JQ1. Gene-drug sensitivity analyses and drug combination studies indicate synergism of BRD4 and kinase inhibition as a plausible reason for the superior potency in cell killing. Combined, our findings indicate promising pot...
Research Interests: Hematopoietic Stem Cells, Humans, Mice, Animals, Drug Design, and 11 moreProteins, Molecular Conformation, Cell Proliferation, Molecular Cancer Therapeutics, Structure activity Relationship, Cell Survival, Antineoplastic Agents, Protein Kinase Inhibitors, janus kinase, Drug synergism, and Pharmacology and pharmaceutical sciences
Research Interests: Biochemistry, Crystallography, Kinetics, Enzyme Inhibitors, Macromolecular X-Ray Crystallography, and 12 moreX Rays, Escherichia coli, Enzyme, Spectrum, Active site, Ligands, Conformational Change, Shikimic acid, Biochemistry and cell biology, binding sites, Medical biochemistry and metabolomics, and stereoisomerism
Selective inhibitors of bromodomain-containing protein 9 (BRD9) may have therapeutic potential in the treatment of human malignancies and inflammatory diseases. A selective small molecule inhibitor that is well tolerated and has proper... more
Selective inhibitors of bromodomain-containing protein 9 (BRD9) may have therapeutic potential in the treatment of human malignancies and inflammatory diseases. A selective small molecule inhibitor that is well tolerated and has proper pharmacokinetic properties is required to explore the function of BRD9 in diseases. BI-9564 (2) is a cell permeable and noncytotoxic BRD9 inhibitor provided to the scientific community to explore BRD9 biology and determine its potential as a drug target.
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Inhibition of cancer-promoting kinases is an established therapeutic strategy for the treatment of many cancers, although resistance to kinase inhibitors is common. One way to overcome resistance is to target orthogonal cancer-promoting... more
Inhibition of cancer-promoting kinases is an established therapeutic strategy for the treatment of many cancers, although resistance to kinase inhibitors is common. One way to overcome resistance is to target orthogonal cancer-promoting pathways. Bromo and Extra-Terminal (BET) domain proteins, which belong to the family of epigenetic readers, have recently emerged as promising therapeutic targets in multiple cancers. The development of multitarget drugs that inhibit kinase and BET proteins therefore may be a promising strategy to overcome tumor resistance and prolong therapeutic efficacy in the clinic. We developed a general computational screening approach to identify novel dual kinase/bromodomain inhibitors from millions of commercially available small molecules. Our method integrated machine learning using big datasets of kinase inhibitors and structure-based drug design. Here we describe the computational methodology, including validation and characterization of our models and t...
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We describe a (19)F NMR method for detecting bromodomain-ligand interactions using fluorine-labeled aromatic amino acids due to the conservation of aromatic residues in the bromodomain binding site. We test the sensitivity, accuracy, and... more
We describe a (19)F NMR method for detecting bromodomain-ligand interactions using fluorine-labeled aromatic amino acids due to the conservation of aromatic residues in the bromodomain binding site. We test the sensitivity, accuracy, and speed of this method with small molecule ligands (+)-JQ1, BI2536, Dinaciclib, TG101348, and acetaminophen using three bromodomains Brd4, BrdT, and BPTF. Simplified (19)F NMR spectra allowed for simultaneous testing of multiple bromodomains to assess selectivity and identification of a new BPTF ligand. Fluorine labeling only modestly affected the Brd4 structure and function assessed by isothermal titration calorimetry, circular dichroism, and X-ray crystallography. The speed, ease of interpretation, and low concentration of protein needed for binding experiments affords a new method to discover and characterize both native and new ligands.
Research Interests: Magnetic Resonance Spectroscopy, Transcription Factors, Gene expression, Macromolecular X-Ray Crystallography, Biological Sciences, and 12 moreHumans, Escherichia coli, CHEMICAL SCIENCES, Acetaminophen, Triazoles, Recombinant Proteins, Protein Binding, Ligands, Halogenation, Molecular probes, binding sites, and Sulfonamides
The extrinsic fluorescence dye 8-anilino-1-naphthalene sulfonate (ANS) is widely used for probing conformational changes in proteins, yet no detailed structure of ANS bound to any protein has been reported so far. ANS has been... more
The extrinsic fluorescence dye 8-anilino-1-naphthalene sulfonate (ANS) is widely used for probing conformational changes in proteins, yet no detailed structure of ANS bound to any protein has been reported so far. ANS has been successfully used to monitor the induced-fit mechanism of MurA [UDPGlcNAc enolpyruvyltransferase (EC )], an essential enzyme for bacterial cell wall biosynthesis. We have solved the crystal structure of the ANS small middle dotMurA complex at 1.7-A resolution. ANS binds at an originally solvent-exposed region near Pro-112 and induces a major restructuring of the loop Pro-112-Pro-121, such that a specific binding site emerges. The fluorescence probe is sandwiched between the strictly conserved residues Arg-91, Pro-112, and Gly-113. Substrate binding to MurA is accompanied by large movements especially of the loop and Arg-91, which explains why ANS is an excellent sensor of conformational changes during catalysis of this pharmaceutically important enzyme.
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Aurora A and JAK2 kinases are involved in cell division and tumor cell survival, respectively. Here we demonstrate that ectopic expression of Aurora A and JAK2 together is more effective than each alone at inducing non-transformed cells... more
Aurora A and JAK2 kinases are involved in cell division and tumor cell survival, respectively. Here we demonstrate that ectopic expression of Aurora A and JAK2 together is more effective than each alone at inducing non-transformed cells to grow in an anchorage-independent manner and to invade. Furthermore, siRNA silencing or pharmacological inhibition of Aurora A and JAK2 with Alisertib and Ruxolitinib, respectively, is more effective than blocking each kinase alone at suppressing anchorage-dependent and -independent growth and invasion as well as at inducing apoptosis. Importantly, we have developed dual Aurora and JAK inhibitors, AJI-214 and AJI-100, which potently inhibit Aurora A, Aurora B and JAK2 in vitro. In human cancer cells, these dual inhibitors block the auto-phosphorylation of Aurora A (Thr-288) and the phosphorylation of the Aurora B substrate histone H3 (Ser-10) and the JAK2 substrate STAT3 (Tyr-705). Furthermore, AJI-214 and AJI-100 inhibit anchorage dependent and in...
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Research Interests: Organic Chemistry, Kinetics, Cancer stem cells, Cell Biology, Cancer Biology, and 15 moreCancer Research, Humans, Phosphorylation, Molecules, Heat Shock Proteins, Calorimetry, Protein Kinase, Cell Cycle Proteins, Enzyme Linked Immunosorbent Assay, Nucleotides, Adenosine Triphosphate, Adenosine Diphosphate, Chaperonins, Protein interaction maps, and binding sites
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Research Interests: Kinetics, Multidisciplinary, Macromolecular X-Ray Crystallography, Crystal structure, Drug Resistance, and 13 moreGenetic modification, Herbicide Resistance, Transgenic Crops, Herbicides, Enzyme, Spectrum, Active site, Structural Properties, Molecular Conformation, Glycine, Roundup Ready, Conformational Change, and glyphosate resistant GM
Research Interests: Breast Cancer, Drug Discovery, Drug development, Multidisciplinary, Transgenic Mice, and 15 moreHumans, Mice, Female, Animals, Male, Phosphorylation, PLoS one, Disease Progression, Growth Factor, Plasma Membrane, Tyrosine, Receptor Tyrosine Kinase, Cell Membrane, Breast Neoplasms, and Protein tyrosine kinases
Research Interests: Kinetics, Molecular modeling, Crystal structure, Pesticide, Mutation, and 15 moreEscherichia coli, Pesticides, Bacteria, Genetic determinism, Enzyme, Active site, Boolean Satisfiability, Glycine, Alanine, Amino Acid Substitution Rates, Crystalline Structure, Binding Site, Klebsiella pneumoniae, Interaction Pattern, and binding sites
MDMX is an important regulator of p53 during embryonic development and malignant transformation. Previous studies showed that casein kinase 1α (CK1α) stably associates with MDMX, stimulates MDMX-p53 binding, and cooperates with MDMX to... more
MDMX is an important regulator of p53 during embryonic development and malignant transformation. Previous studies showed that casein kinase 1α (CK1α) stably associates with MDMX, stimulates MDMX-p53 binding, and cooperates with MDMX to inactivate p53. However, the mechanism by which CK1α stimulates MDMX-p53 interaction remains unknown. Here, we present evidence that p53 binding by the MDMX N-terminal domain is inhibited by the central acidic region through an intramolecular interaction that competes for the p53 binding pocket. CK1α binding to the MDMX central domain and phosphorylation of S289 disrupts the intramolecular interaction, allowing the N terminus to bind p53 with increased affinity. After DNA damage, the MDMX-CK1α complex is disrupted by Chk2-mediated phosphorylation of MDMX at S367, leading to reduced MDMX-p53 binding. Therefore, CK1α is an important functional partner of MDMX. DNA damage activates p53 in part by disrupting CK1α-MDMX interaction and reducing MDMX-p53 bin...
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The o-carboxylic acid substituted bisanilinopyrimidine 1 was identified as a potent hit (Aurora A IC(50) = 6.1 ± 1.0 nM) from in-house screening. Detailed structure-activity relationship (SAR) studies indicated that polar substituents at... more
The o-carboxylic acid substituted bisanilinopyrimidine 1 was identified as a potent hit (Aurora A IC(50) = 6.1 ± 1.0 nM) from in-house screening. Detailed structure-activity relationship (SAR) studies indicated that polar substituents at the para position of the B-ring are critical for potent activity. X-ray crystallography studies revealed that compound 1 is a type I inhibitor that binds the Aurora kinase active site in a DFG-in conformation. Structure-activity guided replacement of the A-ring carboxylic acid with halogens and incorporation of fluorine at the pyrimidine 5-position led to highly potent inhibitors of Aurora A that bind in a DFG-out conformation. B-Ring modifications were undertaken to improve the solubility and cell permeability. Compounds such as 9m with water-solubilizing moieties at the para position of the B-ring inhibited the autophosphorylation of Aurora A in MDA-MB-468 breast cancer cells.
Research Interests: Organic Chemistry, Medicinal Chemistry, Magnetic Resonance Spectroscopy, Macromolecular X-Ray Crystallography, Phosphorylation, and 6 moreLiquid Chromatography / Electrospray Ionization Mass Spectrometry, Aurora kinases, Structure activity Relationship, Protein Kinase Inhibitors, Minimum inhibitory concentration, and Pharmacology and pharmaceutical sciences
Cyclin-dependent kinases (CDKs) are serine/threonine protein kinases that act as key regulatory elements in cell cycle progression. We describe the development of highly potent diaminothiazole inhibitors of CDK2 (IC50 = 0.0009-0.0015 μM)... more
Cyclin-dependent kinases (CDKs) are serine/threonine protein kinases that act as key regulatory elements in cell cycle progression. We describe the development of highly potent diaminothiazole inhibitors of CDK2 (IC50 = 0.0009-0.0015 μM) from a single hit compound with weak inhibitory activity (IC50 = 15 μM), discovered by high-throughput screening. Structure-based design was performed using 35 cocrystal structures of CDK2 liganded with distinct analogues of the parent compound. The profiling of compound 51 against a panel of 339 kinases revealed high selectivity for CDKs, with preference for CDK2 and CDK5 over CDK9, CDK1, CDK4, and CDK6. Compound 51 inhibited the proliferation of 13 out of 15 cancer cell lines with IC50 values between 0.27 and 6.9 μM, which correlated with the complete suppression of retinoblastoma phosphorylation and the onset of apoptosis. Combined, the results demonstrate the potential of this new inhibitors series for further development into CDK-specific chemical probes or therapeutics.