Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.2.1.1 (ACS)
 78,556 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chemically inducible rapid manipulation of small GTPase activity has proven a powerful approach to dissect complex spatiotemporal signaling of these molecular switches. However, overexpression of these synthetic molecular probes freely in the cytosol often results in elevated background activity before chemical induction, which perturbs the cellular basal state and thereby limits their wide application. As a fundamental solution, we have rationally designed and newly developed a strategy to remove unwanted background activity without compromising the extent of induced activation. By exploiting interaction between a membrane lipid and its binding protein, target proteins were translocated from one organelle to another on a time scale of seconds. This improved strategy now allows for rapid manipulation of small GTPases under a physiological state, thus enabling fine dissection of sophisticated signaling processes shaped by these molecules.
ACS Chem Biol 2012 Dec 21
PMID:Rapidly relocating molecules between organelles to manipulate small GTPase activity. 2299 78

Cystic fibrosis (CF), a major life-limiting genetic disease leading to severe respiratory symptoms, is caused by mutations in CF transmembrane conductance regulator (CFTR), a chloride (Cl(-)) channel expressed at the apical membrane of epithelial cells. Absence of functional CFTR from the surface of respiratory cells reduces mucociliary clearance, promoting airways obstruction, chronic infection, and ultimately lung failure. The most frequent mutation, F508del, causes the channel to misfold, triggering its premature degradation and preventing it from reaching the cell surface. Recently, novel small-molecule correctors rescuing plasma membrane localization of F508del-CFTR underwent clinical trials but with limited success. Plausibly, this may be due to the mutant intrinsic plasma membrane (PM) instability. Herein, we show that restoration of F508del-CFTR PM localization by correctors can be dramatically improved through a novel pathway involving stimulation of signaling by the endogenous small GTPase Rac1 via hepatocyte growth factor (HGF). We first show that CFTR anchors to apical actin cytoskeleton (via Ezrin) upon activation of Rac1 signaling through PIP5K and Arp2/3. We then found that such anchoring retains pharmacologically rescued F508del-CFTR at the cell surface, boosting functional restoration by correctors up to 30% of wild-type channel levels in human airway epithelial cells. Our findings reveal that surface anchoring and retention is a major target pathway for CF pharmacotherapy, namely, to achieve maximal restoration of F508del-CFTR in patients in combination with correctors. Moreover, this approach may also translate to other disorders caused by trafficking-deficient surface proteins.
ACS Chem Biol 2013 Feb 15
PMID:HGF stimulation of Rac1 signaling enhances pharmacological correction of the most prevalent cystic fibrosis mutant F508del-CFTR. 2314 78

Optical control of cellular processes is an emerging approach for studying biological systems, affording control with high spatial and temporal resolution. Specifically designed artificial photoswitches add an interesting extension to naturally occurring light-regulated functionalities. However, despite a great deal of structural information, the generation of new tools cannot be based fully on rational design yet; in many cases design is limited by our understanding of molecular details of light activation and signal transduction. Our biochemical and biophysical studies on the established optogenetic tool PA-Rac1, the photoactivatable small GTPase Rac1, reveal how unexpected details of the sensor-effector interface, such as metal coordination, significantly affect functionally important structural elements of this photoswitch. Together with solution scattering experiments, our results favor differences in the population of pre-existing conformations as the underlying allosteric activation mechanism of PA-Rac1, rather than the assumed release of the Rac1 domain from the caging photoreceptor domain. These results have implications for the design of new optogenetic tools and highlight the importance of including molecular details of the sensor-effector interface, which is however difficult to assess during the initial design of novel artificial photoswitches.
ACS Chem Biol 2015 Feb 20
PMID:Structural details of light activation of the LOV2-based photoswitch PA-Rac1. 2536 73

Approximately 15% of all human tumors harbor mutant KRAS, a membrane-associated small GTPase and notorious oncogene. Mutations that render KRAS constitutively active will lead to uncontrolled cell growth and cancer. However, despite aggressive efforts in recent years, there are no drugs on the market that directly target KRAS and inhibit its aberrant functions. In the current work, we combined structure-based design with a battery of cell and biophysical assays to discover a novel pyrazolopyrimidine-based allosteric KRAS inhibitor that binds to activated KRAS with sub-micromolar affinity and disrupts effector binding, thereby inhibiting KRAS signaling and cancer cell growth. These results show that pyrazolopyrimidine-based compounds may represent a first-in-class allosteric noncovalent inhibitors of KRAS. Moreover, by studying two of its analogues, we identified key chemical features of the compound that interact with a set of specific residues at the switch regions of KRAS and play critical roles for its high-affinity binding and unique mode of action, thus providing a blueprint for future optimization efforts.
ACS Omega 2019 Feb 28
PMID:Discovery of High-Affinity Noncovalent Allosteric KRAS Inhibitors That Disrupt Effector Binding. 3084 83

Cryptococcus neoformans is one of the most important human fungal pathogens and causes life-threatening meningoencephalitis in immunocompromised patients. The current gold standard therapy for C. neoformans meningoencephalitis is based on medications that are over 50 years old and is not readily available in regions with high disease burden. Here, we report the mycologic, mechanistic, and pharmacologic characterization of a set of benzothioureas with highly selective fungicidal activity against C. neoformans. In addition, to direct antifungal activity, benzothioureas inhibit C. neoformans virulence traits. On the basis of a set of phenotypic, biochemical, and biophysical assays, the benzothioureas (BTUs) inhibit the late secretory pathway (post-Golgi), possibly through a direct interaction with Sav1, an orthologue of the Sec4-class small GTPase. Importantly, pharmacological characterization of the BTUs indicates it readily penetrates the blood-brain barrier. Together, our data support the further development of this scaffold as an antifungal agent with a novel mechanism of action against C. neoformans.
ACS Infect Dis 2020 03 13
PMID:Benzothiourea Derivatives Target the Secretory Pathway of the Human Fungal Pathogen Cryptococcus neoformans. 3207 95

Activating mutations in the small GTPase NRAS are responsible for driving tumor growth in several cancers. Unfortunately, the development of NRAS inhibitors has proven difficult due to the lack of hydrophobic binding pockets on the protein's surface. To overcome this limitation, we chose to target the post-translational S-palmitoyl modification of NRAS, which is required for its signaling activity. Utilizing an amphiphile-mediated depalmitoylation (AMD) strategy, we demonstrate the ability to directly cleave S-palmitoyl groups from NRAS and inhibit its function. C8 alkyl cysteine causes a dose-dependent decrease in NRAS palmitoylation and inhibits downstream signaling in melanoma cells with an activating mutation in NRAS. This compound reduces cell growth in NRAS-driven versus non-NRAS-driven melanoma lines and inhibits tumor progression in an NRAS-mutated melanoma xenograft mouse model. Our work demonstrates that AMD can effectively suppress NRAS activity and could represent a promising new avenue for discovering lead compounds for treatment of NRAS-driven cancers.
ACS Chem Biol 2020 08 21
PMID:Inhibition of NRAS Signaling in Melanoma through Direct Depalmitoylation Using Amphiphilic Nucleophiles. 3256 9