The extracellular signal-regulated kinases 1 and 2 (ERK1 and ERK2), also called p44 and p42 MAP kinases, are members of the Mitogen Activated Protein Kinase (MAPK) family of proteins found in all eukaryotes. Because the 44 kDa ERK1 and the 42 kDa ERK2 are highly homologous and both function in the same protein kinase cascade, the two proteins are often referred to collectively as ERK1/2 or p44/p42 MAP kinase. The ERK1/2 signaling cascade has been shown to be a critical regulator of cell differentiation, cell physiology and neuronal function. Aberrant control of ERK1/2 activity has been implicated in a variety of pathological conditions, including cancer and autoimmune diseases, and efficient study methods are in demand.
The FACE™ Method
In FACE, cells are cultured in 96-well plates and stimulated to induce the pathway of interest. Following stimulation, the cells are fixed rapidly, which preserves activation-specific protein modifications. Each well is then incubated with a primary antibody specific for the activated protein of interest. Subsequent incubation with secondary HRP-conjugated antibody and developing solution provides a colorimetric or chemiluminescent readout that is quantitative and reproducible (Figure 1). The number of cells in each well can be normalized easily with the provided Crystal Violet solution. FACE Kits also contain primary antibody specific for the native inactive protein, so you can monitor both native and activated protein levels in the same experiment. FACE eliminates cellular extractions, radioactive kinase assays, time-consuming Westerns and inefficient epitope interactions that occur on membranes. FACE is a highly sensitive high-throughput assay designed for detecting activated proteins within mammalian cells.


