ERK1/2 Antibodies

ERK (extracellular signal regulated kinase), also known as MAPK (mitogen-activated protein kinase) has two closely related isoforms designated ERK1 and ERK2 (44 kDa and 42 kDa, respectively). These kinases belong to a family of serine/threonine kinases that are activated upon treatment of cells with a large variety of stimuli including mitogens, hormones, growth factors, cytokines, virus infection, ligands for heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptors, transforming agents, and bioactive peptides. ERK1 and ERK2 are widely expressed and are involved in the regulation of meiosis, mitosis, and postmitotic functions in differentiated cells. Cell stimulation induces the activation of a signaling cascade, the downstream effects of which have been linked to the regulation of cell growth and differentiation as well as the cytoskeleton. ERK1 and ERK2 are phosphorylated within the activation loop on both a threonine and a tyrosine residue (within a Thr-Glu-Tyr motif) by MEKs (MAPK/ERK kinases), thereby greatly elevating the activity of ERK1/2. When growth factors bind to their receptor tyrosine kinase, Ras interacts with Raf, the serine/threonine protein kinase, and activates it, as well. Once activated, Raf phosphorylates serine residue in 2 additional kinases, MEK1/2, which in turn phosphorylates tyrosine/threonine in ERK1/2. Upon activation, the ERKs either phosphorylate a number of cytoplasmic targets or migrate to the nucleus, where they phosphorylate and activate a number of transcription factors such as c-Fos and Elk-1.