Englerin A

Protein target name:

TRPC4, TRPC5

Mechanism of action:

AgonistInduces TRPC4/5-dependent calcium ion influx and cell death

Recommended Concentration for use in cells:

10-1,000 nM

Probe Information

Target and Probe Information

Target Details

Target class:

Ion channel

Subclass:

Transient receptor potential channels

HUGO ID:

HGNC:12336 HGNC:12337

Entrez gene ID:

7223 7224

UNIPROT ID:

Q9UBN4 Q9UL62

Target alias:

Transient receptor potential cation channel subfamily C member 4, HTRP-4, HTRP4, TRP4, Transient receptor potential cation channel subfamily C member 5, PPP1R159, TRP5

Probe Details

Chemical Probes Portal ID:

CPP767

Probe alias:

Englerin A; (-)-englerin A; GTPL8372

PubChem CID:

46242512

ChEMBL ID:

2024567

SMILES string:

O=C(O[C@@H]1[C@]2(C(C)C)C[C@@H](OC(CO)=O)[C@](O2)(C)[C@]3([H])CC[C@@H](C)[C@@]13[H])/C=C/C4=CC=CC=C4

InChi Key:

GACOFEKSDCOVMV-RRYXBOBMSA-N

Control compound:

(+)-englerin A

Physico-chemical properties

Solubility - preferred solvent:

DMSO

Solubility - concentration:

10 mM

Storage Recommendations

Storage (dry powder):

-20°C

Storage (solution):

-20°C

Storage sensitivities:

Limit to 2 freeze-thaw cycles

Validation in Cells and Model Organisms

In vitro validation

On target activity

Structure-activity relationship:

SAR data are available based on compound-induced cytotoxicity in A498 cells (comparison in IC50 values for inhibition of cell viability). The cinnamic ester part can be modified to yield more potent derivatives. Replacement of the isoprpyl group by ethyl or methyl group decreases the activity. Modifications of the glycolic ester lead to decrease in potency.

Off target activity

Probe Selectivity in Vitro:

Englerin A (1 µM) was assayed for inhibition of selected protein kinases (SelectScreen Kinase Profling), GPCRs (GPCRProfiler® services of EMD Millipore) and ion channels (Ion Channel Profiler Services of EMD Millipore). Only weak activity was observed against some of these proteins: ca. 30% inhibition of GPR109A and 15% inhibition of hERG.

In cell validation

On target activity in cells

Potency in cells:

EC50

TRPC4: 11.2 nM, TRPC5: 7.6 nM

Potency assay (cells):

Measurements of the free intracellular calcium ion concentrations using the Fura-2-AM at an extracellular Ca2+ concentration of 1.5 mM in HEK293 cells conditionally expressing human TRPC4 or TRPC5. In A498 cells, which only express TRPC4, EC50=10 nM, and this activity was sensitive to the TRPC4 inhibitor, ML204.

Off target activity in cells

Off target protein and potency (cells):

TRPC6, TRPM2, TRPV4

Potency assay, off target (cells):

No (agonistic) activity of Englerin A was detected in HEK293 cells overexpressing TRPC6, TRPM2 or TRPV4. The activity was assessed based on Ca2+ level measurements at a compound concentration of 1 µM.

Toxicity

Cytoxicity assay:

Yes

Notes on cytotoxicity:

Cytotoxicity was determined by means of metabolic activity (using a WST1 reagent) in A498 cells upon compound addition for 48 h or 4 h. IC50 (4 h incubation)=17 nM; IC50 (48 h incubation)=45 nM. Englerin A was assayed for growth inhibition using the NCI-60 cancer cell panel (see http://pubs.acs.org/doi/abs/10.1021/ol802339w).

Primary Reference

Reference (doi):

10.1002/anie.201411511 10.1371/journal.pone.0127498 10.1074/jbc.M116.755678

Reference (PMID):

25707820 26098886 27875305

SAB Rating

Rating for use in Cells

3 review(s)

Rating for use in Model Organisms

3 review(s)

SAB Members

SAB Comments

Cytotoxicity was observed at 17 nM and 45 nM at different timepoints. Cell EC50s for TRPC4 and TRPC5 are 11 nM and 8 nM, respectively; therefore, there is an insufficient window between on-target activity and cytotoxicity to interpret cellular effects of the compound as target-based.

Mar 13 2017 - 9:44am

There have been several papers showing that this compound activates TRPC4/5 including doi: 10.1002/anie.201411511. The data in those papers is quite convincing that the compound at low nM concentrations activates these channels and that it may mediate some of its anti-tumor activity via this effect. However, there is no convincing dataset regarding potential off-targets, as it has not yet been broadly screened against kinases, GPCRs, ion channels, and so on. Thus, provided the user does the appropriate controls (e.g., TRPC4/5 KO cells as a control), the compound will likely be useful.

Mar 20 2017 - 8:33pm

Englerin A

Probe Information

Target Details

Transient receptor potential cation channel subfamily C member 4, HTRP-4, HTRP4, TRP4, Transient receptor potential cation channel subfamily C member 5, PPP1R159, TRP5

Probe Details

Physico-chemical properties

In vitro validation

In cell validation

Toxicity

Primary Reference

Supporting Organizations

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Englerin A

Probe Information

Target Details

Transient receptor potential cation channel subfamily C member 4, HTRP-4, HTRP4, TRP4, Transient receptor potential cation channel subfamily C member 5, PPP1R159, TRP5

Probe Details

Physico-chemical properties

In vitro validation

In cell validation

Toxicity

Primary Reference

Supporting Organizations

Interested in supporting the portal?