Browse
Submit Data
Databases
API
Help

Dataset Information

13 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Thioesterase-mediated side chain transesterification generates potent Gq signaling inhibitor FR900359.

ABSTRACT: The potent and selective Gq protein inhibitor depsipeptide FR900359 (FR), originally discovered as the product of an uncultivable plant endosymbiont, is synthesized by a complex biosynthetic system comprising two nonribosomal peptide synthetase (NRPS) assembly lines. Here we characterize a cultivable bacterial FR producer, enabling detailed investigations into biosynthesis and attachment of the functionally important FR side chain. We reconstitute side chain assembly by the monomodular NRPS FrsA and the non-heme monooxygenase FrsH, and characterize intermolecular side chain transesterification to the final macrocyclic intermediate FR-Core, mediated by the FrsA thioesterase domain. We harness FrsA substrate promiscuity to generate FR analogs with altered side chains and demonstrate indispensability of the FR side chain for efficient Gq inhibition by comparative bioactivity, toxicity and docking studies. Finally, evolution of FR and side chain biosynthesis is discussed based on bioinformatics analyses. Side chain transesterification boosts potency and target affinity of selective Gq inhibitor natural products.

SUBMITTER: Hermes C

PROVIDER: S-EPMC7794379 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Metabolism of 1-aminoethylphosphinate generates acetylphosphinate, a potent inhibitor of pyruvate dehydrogenase.

Project description:The alanine analogue 1-aminoethylphosphinate [H3C-CH(NH2)-PO2H2] effectively inhibited anthocyanin synthesis in buckwheat hypocotyls and caused an increase in the concentrations of alanine and alanine-derived metabolites. Aminotransferase inhibitors partially alleviated the effects of the analogue. 1-Aminoethylphosphinate did not affect the growth of Klebsiella pneumoniae under anaerobic conditions, but under aerobic conditions it inhibited growth and caused the massive excretion of pyruvate. The analogue inhibited the pyruvate dehydrogenase complex in vitro in the presence of an aminotransferase activity. The transamination product of 1-aminoethylphosphinate, acetylphosphinate (H3C-CO-PO2H2), was found to inhibit the pyruvate dehydrogenase complex in a time-dependent reaction that followed first-order and saturation kinetics and required the presence of thiamin pyrophosphate.

| S-EPMC1148548 | biostudies-other

Extracellular Succinate Hyperpolarizes M2 Macrophages through SUCNR1/GPR91-Mediated Gq Signaling

Project description:Succinate functions both as a classical TCA cycle metabolite and as an extracellular metabolic stress signal sensed by the mainly Gi-coupled succinate receptor, SUCNR1. In the present study, we characterize and compare effects and signaling pathways activated by succinate and both classes of non-metabolite SUCNR1 agonists. By use of specific receptor and pathway inhibitors, rescue in G protein depleted cells and monitoring of receptor G protein activation by BRET we surprisingly identify Gq rather than Gi signaling, to be responsible for SUCNR1-mediated effects on basic transcriptional regulation. Importantly, in primary human M2 macrophages, where SUCNR1 is highly expressed, we demonstrate that physiological concentrations of extracellular succinate act through SUCNR1 activated Gq signaling to efficiently regulate transcription of immune function genes in a manner that hyperpolarizes their M2 versus M1 phenotype. Thus, sensing of stress-induced extracellular succinate by SUCNR1 is an important transcriptional regulator in human M2 macrophages through Gq signaling.

2021-04-30 | GSE173611 | GEO

Kinetic scaffolding mediated by a phospholipase C-beta and Gq signaling complex.

Project description:Transmembrane signals initiated by a broad range of extracellular stimuli converge on nodes that regulate phospholipase C (PLC)-dependent inositol lipid hydrolysis for signal propagation. We describe how heterotrimeric guanine nucleotide-binding proteins (G proteins) activate PLC-?s and in turn are deactivated by these downstream effectors. The 2.7-angstrom structure of PLC-?3 bound to activated G?(q) reveals a conserved module found within PLC-?s and other effectors optimized for rapid engagement of activated G proteins. The active site of PLC-?3 in the complex is occluded by an intramolecular plug that is likely removed upon G protein-dependent anchoring and orientation of the lipase at membrane surfaces. A second domain of PLC-?3 subsequently accelerates guanosine triphosphate hydrolysis by G?(q), causing the complex to dissociate and terminate signal propagation. Mutations within this domain dramatically delay signal termination in vitro and in vivo. Consequently, this work suggests a dynamic catch-and-release mechanism used to sharpen spatiotemporal signals mediated by diverse sensory inputs.

| S-EPMC3046049 | biostudies-literature

C-peptide inhibitors of Ebola virus glycoprotein-mediated cell entry: effects of conjugation to cholesterol and side chain-side chain crosslinking.

Project description:We previously described potent inhibition of Ebola virus entry by a 'C-peptide' based on the GP2 C-heptad repeat region (CHR) targeted to endosomes ('Tat-Ebo'). Here, we report the synthesis and evaluation of C-peptides conjugated to cholesterol, and Tat-Ebo analogs containing covalent side chain-side chain crosslinks to promote ?-helical conformation. We found that the cholesterol-conjugated C-peptides were potent inhibitors of Ebola virus glycoprotein (GP)-mediated cell entry (~10(3)-fold reduction in infection at 40 ?M). However, this mechanism of inhibition is somewhat non-specific because the cholesterol-conjugated peptides also inhibited cell entry mediated by vesicular stomatitis virus glycoprotein G. One side chain-side chain crosslinked peptide had moderately higher activity than the parent compound Tat-Ebo. Circular dichroism revealed that the cholesterol-conjugated peptides unexpectedly formed a strong ?-helical conformation that was independent of concentration. Side chain-side chain crosslinking enhanced ?-helical stability of the Tat-Ebo variants, but only at neutral pH. These result provide insight into mechanisms of C-peptide inhibiton of Ebola virus GP-mediated cell entry.

| S-EPMC3822755 | biostudies-literature

An NKT-mediated autologous vaccine generates CD4 T-cell dependent potent antilymphoma immunity.

Project description:Relapses occurring in most patients with lymphoma after antibody or chemotherapy highlight a need for effective vaccination approaches. Autologous tumors are ideal sources of patient-specific tumor antigens for vaccines; however, their poor immunogenicity has been a major obstacle in practice. Natural killer T (NKT) cells have recently emerged as crucial regulators of autoimmunity and tumor immunosurveillance. Here, we show that an autologous lymphoma vaccine that activates NKT cells generated tumor-specific protective immunity in experimental mice. Single vaccination with alpha-galactosylceramide (alphaGC)-loaded A20 lymphoma cells elicited effective antitumor immunity against tumor challenge. This vaccination strategy also induced significant tumor regression in A20-bearing mice. Importantly, the survivors from primary tumor inoculation were all resistant to tumor rechallenge, indicative of established adaptive memory immunity. Depletion as well as adoptive transfer studies revealed an exclusive role of conventional CD4(+) but not CD8(+) T cells in mediating antitumor immunity. In addition, we found normal hematopoietic compartments in the vaccinated mice. Therefore, NKT ligand-loaded lymphoma elicits long-lasting and effective antitumor immunity, which can be further developed as patient- and tumor-specific immunotherapy against human lymphomas.

| S-EPMC1976361 | biostudies-literature

Arginine Side-Chain Hydrogen Exchange: Quantifying Arginine Side-Chain Interactions in Solution.

Project description:The rate with which labile backbone hydrogen atoms in proteins exchange with the solvent has long been used to probe protein interactions in aqueous solutions. Arginine, an essential amino acid found in many interaction interfaces, is capable of an impressive range of interactions via its guanidinium group. The hydrogen exchange rate of the guanidinium hydrogens therefore becomes an important measure to quantify side-chain interactions. Herein we present an NMR method to quantify the hydrogen exchange rates of arginine side-chain 1 H? protons and thus present a method to gauge the strength of arginine side-chain interactions. The method employs 13 C-detection and the one-bond deuterium isotope shift observed for 15 N? to generate two exchanging species in 1 H2 O/2 H2 O mixtures. An application to the protein T4 Lysozyme is shown, where protection factors calculated from the obtained exchange rates correlate well with the interactions observed in the crystal structure. The methodology presented provides an important step towards characterising interactions of arginine side-chains in enzymes, in phase separation, and in protein interaction interfaces in general.

| S-EPMC6391956 | biostudies-literature

Thioesterase superfamily member 2 (Them2)/acyl-CoA thioesterase 13 (Acot13): a homotetrameric hotdog fold thioesterase with selectivity for long-chain fatty acyl-CoAs.

Project description:Them2 (thioesterase superfamily member 2) is a 140-amino-acid protein of unknown biological function that comprises a single hotdog fold thioesterase domain. On the basis of its putative association with mitochondria, accentuated expression in oxidative tissues and interaction with StarD2 (also known as phosphatidylcholine-transfer protein, PC-TP), a regulator of fatty acid metabolism, we explored whether Them2 functions as a physiologically relevant fatty acyl-CoA thioesterase. In solution, Them2 formed a stable homotetramer, which denatured in a single transition at 59.3 degrees C. Them2 exhibited thioesterase activity for medium- and long-chain acyl-CoAs, with Km values that decreased exponentially as a function of increasing acyl chain length. Steady-state kinetic parameters for Them2 were characteristic of long-chain mammalian acyl-CoA thioesterases, with minimal values of Km and maximal values of kcat/Km observed for myristoyl-CoA and palmitoyl-CoA. For these acyl-CoAs, substrate inhibition was observed when concentrations approached their critical micellar concentrations. The acyl-CoA thioesterase activity of Them2 was optimized at physiological temperature, ionic strength and pH. For both myristoyl-CoA and palmitoyl-CoA, the addition of StarD2 increased the kcat of Them2. Enzymatic activity was decreased by the addition of phosphatidic acid/phosphatidylcholine small unilamellar vesicles. Them2 expression, which was most pronounced in mouse heart, was associated with mitochondria and was induced by activation of PPARalpha (peroxisome-proliferator-activated receptor alpha). We conclude that, under biological conditions, Them2 probably functions as a homotetrameric long-chain acyl-CoA thioesterase. Accordingly, Them2 has been designated as the 13th member of the mammalian acyl-CoA thioesterase family, Acot13.

| S-EPMC3086008 | biostudies-literature

Pivotal Role of an Aliphatic Side Chain in the Development of an HDM2 Inhibitor.

Project description:Introduction of an aliphatic side chain to a key position of a novel piperidine-based HDM2 inhibitor scaffold resulted in significant potency gains, enabling further series progression.

| S-EPMC4027732 | biostudies-literature

Alternative intronic polyadenylation generates the interleukin-6 trans-signaling inhibitor sgp130-E10.

Project description:Interleukin (IL)-6 signals via a receptor complex composed of the signal-transducing ?-receptor gp130 and the non-signaling membrane-bound or soluble IL-6 receptor ? (IL-6R, sIL-6R), which is referred to as classic and trans-signaling, respectively. IL-6 trans-signaling is functionally associated with the development of chronic inflammatory diseases and cancer. Soluble gp130 (sgp130) variants are natural inhibitors of trans-signaling. Differential splicing yields sgp130 isoforms. Here, we describe that alternative intronic polyadenylation in intron 10 of the gp130 transcript results in a novel mRNA coding for an sgp130 protein isoform (sgp130-E10) of 70-80 kDa. The sgp130-E10 protein was expressed in vivo in human peripheral blood mononuclear cells. To assess the biological activity of sgp130-E10, we expressed this variant as Fc-tagged fusion protein (sgp130-E10Fc). Recombinant sgp130-E10Fc binds to a complex of IL-6 and sIL-6R, but not to IL-6 alone, and specifically inhibits IL-6 trans-signaling. Thus, it might play an important role in the regulation of trans-signaling in vivo.

| S-EPMC4139227 | biostudies-other

Timosaponin AIII induces antiplatelet and antithrombotic activity via Gq-mediated signaling by the thromboxane A2 receptor.

Project description:The thromboxane (Tx) A2 pathway is a major contributor to the amplification of initial platelet activation and is therefore a key drug target. To identify potent small-molecule inhibitors of the thromboxane prostaglandin (TP) receptor, we screened a small steroidal saponin library using U46619-induced rat platelet aggregation assays. Timosaponin AIII (TAIII) was identified as a potent inhibitor of U46619-induced rat platelet aggregation and exhibited superior selectivity for the TP receptor versus other G protein-coupled receptors and a PKC activator. TAIII inhibited U46619-induced rat platelet aggregation independent of increases in cAMP and cGMP and the inhibition of TxA2 production. Both PKC and PLC activators restored TAIII-inhibited platelet aggregation, whereas TAIII did not inhibit platelet aggregation induced by co-activation of the G12/13 and Gz pathways. Furthermore, TAIII did not affect the platelet shape change or ROCK2 phosphorylation evoked by low-dose U46619. In vivo, TAIII prolonged tail bleeding time, reduced the mortality of animals with acute pulmonary thromboembolism and significantly reduced venous thrombus weight. Our study suggests that TAIII, by preferentially targeting Gq-mediated PLC/PKC signaling from the TP receptor, induces stronger in vitro antiplatelet activity and in vivo antithrombotic effects and may be an excellent candidate for the treatment of thrombotic disorders.

| S-EPMC5146924 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data