MNK1 Cellular Phosphorylation Assay Service

MNK1 Cellular Phosphorylation Assay (intracellular kinase activity assay) for compound screening and profiling in intact cells

Target Overview

Target Description

The MAP kinase interacting serine/threonine kinase 1 (MKNK1; MNK1) activates translation of proliferation associated proteins by phosphorylation of elongation initiation factor 4E (eIF4E) at serine 209. MNK1 itself is phosphorylated and activated by the p38 kinases and kinases in the Erk pathway downstream of many receptor tyrosine kinases.

HGNC Reference



Cell Line


Target Expression


Assay Properties

Assay Description

The human T cell lymphoma cell line Karpas-299 expresses a constitutively active fusion protein of the receptor tyrosine kinase ALK (NPM-ALK) which activates the ERK pathway and subsequently MNK1, resulting in phosphorylation of eIF4E at Ser209. Inhibition of MNK1 with the cognate MNK1 inhibitor CGP-57380 results in a decrease of phospho-levels of MNK1 substrate eIF4E (see Fig. 1). The cellular eIF4E phosphorylation assay is suited for the characterization of inhibitors of MNK1. In the assay, levels of phospho-Ser209 of eIF4E are quantified by Sandwich-ELISA technique.


Substrate phosphorylation as a readout of intracellular kinase activity via ELISA

Screening Location

Freiburg, Germany

Further Information

More information can be found on our website Cellular Phosphorylation Assay Services.

Reference compound IC50 for MNK1

Reference compound IC50 for MNK1

The known MNK1 Inhibitor CGP-57380 (4-Amino-5-(4-fluoroanilino)-pyrazolo[3,4-d]pyrimidine) acted as inhibitor of phosphorylation of eIF4E at Ser209 in Karpas-299 cells and generated highly reproducible IC50 values in the cellular MNK1 activity assay. The graph shows a representative result.