STEP activator
BI-0314
BI-0314 is the first allosteric activator for STEP. It binds to the active phosphatase domain and upregulates its catalytic activity. Its activity has been demonstrated in enzymatic assays showing an activation of STEP of ~60% at 500 µM using different readouts. The selectivity of BI-0314 was tested against the tyrosine phosphatases PTP1B and TCPTP and no signs of activation were observed at concentrations up to 500 µM.
More information
STEP is a multi-domain tryrosine phosphatase which exists as two splice variants, the membrane anchored longer isoform STEP61 and the cytosolic STEP46. Both isoforms share the identical kinase interaction motif (KIM) and the protein tyrosine phosphatase (PTP) domain with the phosphatase consensus motif C(X)5R. The KIM domain mediates binding to various target kinases with high affinity, while the PTP domain catalyzes their subsequent dephosphorylation. To avoid developing ligands which potentially suffer from substrate specificity, we preferred targeting the PTP domain over the KIM domain. The PTP domain bears various conserved structural motifs, such as the WPD loop, which is crucial for the catalytic step, as its aspartate (D461) mediates proton transfer to the phosphate leaving group.
To elucidate the mode of action, an X-ray structure with BI-0314 bound STEP has been solved demonstrating remote site binding ~20 Å away from the active phosphatase site. The allosteric binding site could be confirmed also in solution by 15N TROSY NMR. Long range allosteric mechanisms have been confirmed by extensive molecular dynamics simulations. The identification of a druggable allosteric pocket provides new opportunities for the discovery of selective STEP modulators as treatment options for CNS disorders.
STEP structure and allosteric binding site with bound ligand (orange sticks), PDB code: 6H8S.
BI-0314 displays an activation of STEP of ~60% at 500µM on the dephosphorylation of a pFYN derived peptide.
| Probe name | BI-0314 | ||
| MW [Da, free base]a | 286.3 | ||
| Enzyme | Substrate | Assay technology | Effect of BI-0314 in assay |
| hSTEP46b | pFYN-peptide | AlphaLISA | Activating 56% ± 5% at 500 µM, (n=8) 33% ± 12% at 100 µM, (n=12) |
| hSTEP46b | pFYN-peptide | RapidFire (MS) | Activating 28% ± 5% at 100 µM, (n=4) |
| PTP domain of hSTEPb | pFYN-peptide | AlphaLISA | Activating 61% ± 6% at 500 µM, (n=10) |
| hSTEP46b | DiFMUP | Fluorescence | Activating 48% ± 8% at 1000 µM, (n=3) 27% ± 5% at 300 µM, (n=3) |
a For the salt form you will get, please refer to the label on the vial and for the molecular weight of the salt, please refer to the FAQs
b for detailed assay conditions see Ref. 3
The phylogenetically closest enzyme (TCPTP) and the “generic” tyrosine phosphatase PTP1B have been investigated and at concentrations up to 500 µM of BI-0314 no signs of activation could be observed. No other panels have been tested.
| SELECTIVITY DATA AVILABLE | BI-0314 |
SafetyScreen44™ with kind support of  | Yes |
| Invitrogen® | No |
| DiscoverX® | No |
| Dundee | No |
Download selectivity data: BI-0314_selectivityData.xlsx
The X-ray crystal structure of target in complex with BI-0314 is available (PDB code: 6H8S).
No other STEP activators are described so far. However, there are quite potent orthosteric inhibitors described, which only show moderate selectivity over other phosphatases. (Xu 20141, Witten 20172)
BI-0314 is the first allosteric activator for STEP (PTPN5). The compound may be used as starting point for the development of selective STEP activators.
Inhibitor of the Tyrosine Phosphatase STEP Reverses Cognitive Deficits in a Mouse Model of Alzheimer's Disease
Xu J., Chatterjee M., Baguley T. D., Brouillette J., Kurup P., Ghosh D., Kanyo J., Zhang Y., Seyb K., Ononenyi C., Foscue E., Anderson G. M., Gresack J., Cuny G. D., Glicksman M. A., Greengard P., Lam T. T., Tautz L., Nairn A. C., Ellman J. A., Lombroso P. J.
PLOS Biology, 2014, 12, e1001923.
Allosteric activation of the protein tyrosine phosphatase STEP by a fragment-like molecule
Tautermann C. S., Binder F., Büttner F. H., Eickmeier C., Fiegen D., Gross U., Grundl M. A., Heilker R., Hobson S., Hoerer S., Hoerer S., Luippold A., Mack V., Montel F., Peters S., Bhattacharya S., Vaidehi N., Schnapp G., Thamm S., Zeeb M.
J. Med. Chem., ASAP, 2018, 62, 306-316
Genetic reduction of striatal-enriched tyrosine phosphatase (STEP) reverses cognitive and cellular deficits in an Alzheimer’s disease mouse model
Zhang Y., Kurup P., Xu J., Carty N., Fernandez S. M., Nygaard H. B., Pittenger C., Greengard P., Strittmatter S. M., Nairn A. C., Lombroso P. J.
Proceedings of the National Academy of Sciences, 2010, 107, 19014-19019.
The tyrosine phosphatase STEP: implications in schizophrenia and the molecular mechanism underlying antipsychotic medications
Carty N. C., Xu J., Kurup P., Brouillette J., Goebel-Goody S. M., Austin D. R., Yuan P., Chen G., Correa P. R., Haroutunian V., Pittenger C., Lombroso P. J.
Transl Psychiatry, 2012, 2, e137.
When you plan a publication, please use the following acknowledgement:
BI-0314 was kindly provided by Boehringer Ingelheim via its open innovation platform opnMe, available at https://www.opnme.com.