Tofacitinib

Reagent Authentication Certificate:

Chemical Probes Portal Tofacitinib.pdf

Protein target name:

JAK1, JAK2, JAK3

Recommended Concentration for use in cells:

Up to 120 nM

Probe Availability

MedChem Express (477600-75-2)

Abcam (477600-75-2)

Tocris (540737-29-9)

Cayman (540737-29-9)

MilliporeSigma (540737-29-9)

Probe Information

Target and Probe Information

Target Details

Target class:

Protein kinase

Subclass:

Tyrosine Kinase

HUGO symbol:

JAK3

Entrez gene ID:

3718

Probe Details

Chemical Probes Portal ID:

CPP86

Probe alias:

Tasocitinib, CP-690550, CP 690550

PubChem CID:

9926791

ChEMBL ID:

CHEMBL221959

SMILES string:

C[C@@H]1CCN(C[C@@H]1N(C)C2=NC=NC3=C2C=CN3)C(=O)CC#N

InChi Key:

UJLAWZDWDVHWOW-YPMHNXCESA-N

PAINs evaluation:

PAINs free

Validation in Cells and Model Organisms

In vitro validation

On target activity

Potency:

IC50

1 nM

Off target activity

Potency (off target):

IC50

Off target protein and potency:

JAK1 112 nMJAK2 20 nM

Potency assay (off target):

IC50 > 3,000 for 30 additional kinases

In cell validation

On target activity in cells

Potency in cells:

IC50

160 nM

Potency assay (cells):

IL-2-induced JAK3 phosphorylation

Target engagement assay (cells):

Indirect: inhibition of autophosphorylation

Primary Reference

Reference (doi):

10.1126/science.1087061

Reference (PMID):

14593182

SAB Rating

Rating for use in Cells

3 review(s)

Rating for use in Model Organisms

3 review(s)

SAB Members

SAB Comments

This probe will always inhibit both JAK1 and JAK3 at any in vitro and in vivo dose explored. At higher doses, it will inhibit JAK2 , and at even higher doses, it inhibits TYK2. Care in data interpretation and target association is, therefore, warranted within the JAK family of kinases.

In human primary cell types, tofacitinib is active and non-cytotoxic from 14 nM to 90 uM. Between 14-120 nM, it is active in human primary cell-based assays that are JAK3/JAK1 dependent. At 370 nM and above, it is active in assays that are JAK1/JAK2 dependent (DOI:10.1039/9781782620136-00088).

There is convincing evidence demonstrating direct target engagement of JAK1, JAK2, JAK3 and TYK2 by tofacitinib in vitro using X-ray crystallography (i.e., PMIDs 20478313, 19361440). Based on the reported IC50 values in cell-free systems, tofacitinib will most likely inhibit JAK1, JAK2 and JAK3 to varying degrees at the recommended concentrations (1-120 nM); therefore, users should be cautious about assuming isoform selectivity in their particular system. The original report (PMID 14593182) does not demonstrate direct target engagement in cells, but rather uses indirect measurements of JAK and STAT phosphorylation, as well as inflammatory/disease endpoints in animal models. The relative engagement of each JAK isoform by tofacitinib is unclear in these systems (i.e., IC50 values may or may not reflect the cellular inhibition by tofacitinib). Users should consider assaying each JAK isoform (e.g., phosopho-JAK1/2/3) in their cell-based and in vivo experiments to define the specific contributions of each JAK-dependent pathway, especially if isoform-specific effects are being studied.

Tofacitinib

Probe Availability

Probe Information

Target Details

Probe Details

In vitro validation

In cell validation

Primary Reference

Supporting Organizations

Interested in supporting the portal?

Search form

Tofacitinib

Probe Availability

Probe Information

Target Details

Probe Details

In vitro validation

In cell validation

Primary Reference

Supporting Organizations

Interested in supporting the portal?