Signal-Regulated Kinases ERK-1,-2,-3,-5)

Introduction

The mitogen-activated protein kinase (MAPK) pathway exists in all eukaryotes. It consists of several subgroups including ERK 1/2 (extracellular signal-regulated kinase), JNK and p38 kinases.

These kinases regulate and control fundamental cellular processes including proliferation, apoptosis, survival and differentiation. Many different stimuli, including growth factors, cytokines, virus infection, ligands for G protein-coupled receptors and transforming agents, activate the ERK1 and ERK2 pathways. When growth factorsbind to the 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 further kinases, MEK1/2, which in turn phosphorylates tyrosine/threonine in extracellular-signal-regulated kinase (ERK) 1/2. 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-Fosand Elk-1.

MAP kinases are characterized by their requirement for dual phosphorylation for full activation. ERK1 (44kDa) and ERK2 (42kDa) kinases are characterized by their requirement for dual phosphorylation at a conserved T-E-Y motif. ERK3 is a member of the Ser/Thr protein kinase family,and is most closely related to mitogen-activated protein kinases. Extracellular signal-related protein kinase 5/big mitogen-activated protein kinase 1 (ERK5/BMK1) is an 88 kDa member of the MAP kinase superfamily that becomes fully activated when phosphorylated on threonine 218 and tyrosine 220 by MEK5. ERK5 is activated in response to certain growth factors and bioactive peptides, however the upstream activators are distinct from those that activate ERK1/2.

Antibody Panel to ERK-1, -2, -3, and -5

Acris Antibodies offers a range of polyclonal antibodies to different MAP Kinases, including products for Immunohistochemical applications on frozen or Paraffin embedded sections, Immunofluorescence and /or Western blotting.

Phosphorylation site specific antibodies to ERK1/2 and ERK5 are also available.

Fig.1: Detection of ERK1 with RA15000. 2 ng of recombinant ERK1 and ERK2; lysates from human MCF-7, HepG2, Jurkat and rat PC12 cells resolved by SDS-PAGE, transferred to Immobilon membrane and immunoblotted with 0.1 µg/mL rabbit anti-ERK1.

Fig.2: Western Blot. Extracts prepared from PC12 cells not stimulated (-), or stimulated with NGF (+) were resolved by SDS-PAGE on a 10% polyacrylamide gel and transferred to nitrocellulose. Membranes were blocked with a 5% BSA-TBST buffer overnight at 4°C, then were incubated with ERK1&2 pan antibody BP7059 for two hours at room temperature in a 3% BSA-TBST buffer. After washing, membranes were incubated with goat F(ab’)2 anti-rabbit IgG alkaline phosphatase and signals were detected using the Tropix WesternStar™ method. The data show that the anti-ERK1&2 antibody allows the total amount of ERK1&2 to be measured. The resulting signals serve as a useful control in assessing the degree of actuation as detected using an antibody to the dually phosphorylated (active) form of ERK1&2.

Available Antibody Panel to ERK’s

MAP-Kinases, ERK’s antibody.

Literature

p38 MAPK, microglial signaling, and neuropathic pain. Ji RR, Suter MR. Mol Pain. 2007 Nov 1;3:33

Fischer AM, Katayama CD, Pages G, Pouyssegur J, Hedrick SM. The Role of Erk1 and Erk2 in Multiple Stages of T Cell Development. Immunity. 2005 Oct;23(4):431-443.

Seternes OM, Mikalsen T, Johansen B, Michaelsen E, Armstrong CG, Morrice NA, Turgeon B, Meloche S, Moens U, Keyse SM. Activation of MK5/PRAK by the atypical MAP kinase ERK3 defines a novel signal transduction pathway. EMBO J. 2004 Dec 8; 23(24):4780-91. Erratum in: EMBO J. 2005 Feb 23; 24(4):873.

Sohn SJ, Li D, Lee LK, Winoto A. Transcriptional regulation of tissue-specific genes by the ERK5 mitogen-activated protein kinase. Mol Cell Biol. 2005 Oct; 25(19): 8553-66.