2. Signaling Pathways
  3. MAPK/ERK Pathway
  4. MEK
  5. MEK5 Isoform

MEK5

MEK5 (MAP2K5) is a dual-specificity MAPK kinase that functions as the direct upstream activator of ERK5/MAPK7, forming the core of the MEK5-ERK5 signaling module within the mitogen-activated protein kinase network[1][2]. Mechanistically, MEK5 is activated downstream of MEKK2 and MEKK3, and transmits signals that regulate cell survival, proliferation, differentiation, migration, and stress-responsive transcriptional programs through ERK5 activation[2][3]. The pathway is unusual among MAPK cascades because it responds to both mitogenic and stress-related stimuli, including cytokines, oxidative stress, osmotic stress, and fluid shear stress, linking environmental sensing to adaptive cellular responses[1]. In physiological systems, MEK5-ERK5 signaling has a prominent role in endothelial mechanotransduction and contributes to the maintenance of tissue integrity in mechanically stressed tissues such as bone, cartilage, and muscle[1]. In disease models, aberrant activation of the pathway has been associated with tumor cell survival, proliferation, therapeutic resistance, and adaptive signaling during targeted cancer treatment[1][4]. Compared with the closely related MEK1/2-ERK1/2 pathway, MEK5 exhibits distinct signaling specificity because MEK5 activates ERK5 but not ERK1/2, whereas MEK1/2 do not activate ERK5, supporting the functional separation of these parallel MAPK modules[4]. For experimental applications, selective MEK5 inhibitors such as BIX02189 are widely used to interrogate MEK5-ERK5 pathway function in cellular and disease models[4][5].

MEK5 Related Products (4):

Cat. No. Product Name Effect Purity
  • HY-12056
    BIX02189
    		Inhibitor 99.72%
    BIX02189 is a potent and selective MEK5 inhibitor with an IC50 of 1.5 nM. BIX02189 also inhibits ERK5 catalytic activity with an IC50 of 59 nM.
  • HY-114189
    GW284543
    		Inhibitor 99.94%
    GW284543 (UNC10225170) is a selective MEK5 inhibitor. GW284543 reduces pERK5, and decreases endogenous MYC protein.
  • HY-12055
    BIX02188
    		Inhibitor 98.05%
    BIX02188 is a potent MEK5-selective inhibitor with an IC50 of 4.3 nM. BIX02188 inhibits ERK5 catalytic activity, with an IC50 of 810 nM.
  • HY-114189A
    GW284543 hydrochloride
    		Inhibitor
    GW284543 (UNC10225170) hydrochloride is a selective MEK5 inhibitor. GW284543 reduces pERK5, and decreases endogenous MYC protein.