| 1995 |
MEK5 was identified as a novel MEK family member that does not phosphorylate ERK1, ERK2, ERK3, JNK/SAPK, or p38, nor is it phosphorylated by Raf-1, c-Mos, or MEKK1, indicating it lies in a distinct MAP kinase pathway. Alternative splicing produces a 50-kDa alpha isoform (expressed in liver and brain, particulate) and a 40-kDa beta isoform (ubiquitously distributed, primarily cytosolic), with differential subcellular localization determined by a 23-amino-acid N-terminal domain in MEK5α. |
PCR cloning, substrate phosphorylation assays in vitro, subcellular fractionation, tissue distribution analysis |
The Journal of biological chemistry |
High |
7499418
|
| 1999 |
MEKK3 physically interacts with MEK5 (identified by yeast two-hybrid and confirmed by co-immunoprecipitation in mammalian cells), and a dominant-active MEKK3 stimulates BMK1/ERK5 activity through MEK5; MEKK3 kinase activity is required for growth-factor-mediated activation of endogenous BMK1. |
Yeast two-hybrid screen, co-immunoprecipitation, dominant-active/kinase-dead mutant expression |
The Journal of biological chemistry |
High |
10593883
|
| 1999 |
The ERK5/MEK5 pathway is required for Raf-dependent cellular transformation; constitutively active MEK5 (MEK5DD) synergizes with Raf to transform NIH 3T3 cells. Endogenous Raf-1 binds specifically to endogenous ERK5 (not ERK2 or SAPK), and Raf-1 contributes to Ras activation of ERK5 through protein-protein interactions rather than catalytic activity. |
Co-immunoprecipitation, NIH 3T3 transformation assay, dominant-negative and constitutively active MEK5 mutants |
The Journal of biological chemistry |
High |
10531364
|
| 2000 |
MEKK2 binds MEK5 via yeast two-hybrid and co-immunoprecipitation, activates BMK1/ERK5 through MEK5, and does so to a greater extent than MEKK3. A dominant-negative MEK5 specifically blocks MEKK2-induced BMK1/ERK5 activation without affecting JNK, establishing MEK5 as a specific downstream effector of MEKK2 in the BMK1/ERK5 pathway. |
Yeast two-hybrid, co-immunoprecipitation, dominant-negative MEK5, kinase assays |
The Journal of biological chemistry |
High |
11073940
|
| 2001 |
Constitutively active MEK5 in cardiomyocytes induces serial sarcomere assembly and an elongated hypertrophic morphology, and dominant-negative MEK5 specifically blocks LIF-induced elongation. Cardiac-specific expression of activated MEK5 in transgenic mice causes eccentric cardiac hypertrophy progressing to dilated cardiomyopathy and sudden death, establishing MEK5-ERK5 as the pathway mediating cytokine-induced serial sarcomere assembly. |
Adenoviral expression of CA/DN MEK5 in cardiomyocytes, transgenic mice, morphological analysis |
The EMBO journal |
High |
11387209
|
| 2001 |
Atypical protein kinase C isoforms (aPKCs, zetaPKC and lambda/iotaPKC) interact with MEK5 in an EGF-inducible manner, and this interaction is required and sufficient for MEK5 activation in response to EGF. aPKCs activate the Jun promoter through the MEF2C element (an ERK5 target) via MEK5. |
Co-immunoprecipitation, dominant-negative and constitutively active constructs, reporter assays |
Molecular and cellular biology |
Medium |
11158308
|
| 2003 |
The PB1 domains of MEKK2 and MEKK3 heterodimerize with the PB1 domain of MEK5 (but not with each other) both in vitro and in vivo. Deletion or mutation of the MEKK2 PB1 domain abolishes MEKK2-MEK5 complexes, and expression of the free MEKK2 or MEKK3 PB1 domain specifically inhibits ERK5 activation without affecting p38 or JNK pathways. |
In vitro PB1 domain binding, co-immunoprecipitation, mutagenesis, dominant-interference PB1 domain expression |
The Journal of biological chemistry |
High |
12912994
|
| 2003 |
Activation of the MEK5-ERK5 pathway causes phosphorylation and stabilization of c-Fos and Fra-1. ERK5 directly phosphorylates c-Fos at sites distinct from ERK1/2 phosphorylation sites, and the C-terminal half of ERK5 is necessary for maximal transactivation of c-Fos and Fra-1. |
Constitutively active MEK5, phosphorylation assays, transactivation reporter assays, truncation mutants of ERK5 |
Genes to cells : devoted to molecular & cellular mechanisms |
Medium |
12622723
|
| 2003 |
MEK5 overexpression in prostate cancer cells stimulates proliferation, motility, and invasion, markedly increases MMP-9 (but not MMP-2) mRNA expression, and activates AP-1 (but not NF-κB) transcription via the MMP-9 promoter, establishing MEK5 as an upstream regulator of MMP-9/AP-1 in prostate cancer invasion. |
MEK5 transfection, luciferase reporter assays, EMSA, invasion assays |
Oncogene |
Medium |
12618764
|
| 2004 |
Endogenous MEK5 and ERK5 are localized predominantly in the nucleus in both resting and EGF-stimulated HeLa and Rat-1 cells, bound to detergent-resistant nuclear moieties, whereas their upstream activator MEKK2 is cytosolic at rest and translocates to the nucleus upon EGF stimulation. |
Immunofluorescence microscopy, in situ detergent extraction (NP-40), subcellular fractionation |
Journal of cell science |
High |
15075238
|
| 2004 |
The NMR structure of the PKCiota PB1 domain reveals it adopts a ubiquitin fold with an OPCA motif forming an acidic surface that mediates interaction with the basic surface of target PB1 domains including MEK5, confirmed by mutational analysis. |
NMR structure determination, mutational analysis of protein-protein interaction |
The Journal of biological chemistry |
High |
15143057
|
| 2004 |
CT-1-induced cardiac hypertrophy is mediated by the MEK5-ERK5 pathway: dominant-negative MEK5 suppresses CT-1-induced hypertrophy (protein synthesis, BNP secretion, cell surface area increase) while dominant-negative MEK1 does not, and CT-1 activates ERK5 phosphorylation that is blocked by SOCS1/3 overexpression. |
Adenoviral dominant-negative MEK5/MEK1, SOCS overexpression, phosphorylation assays, hypertrophy markers |
Journal of molecular and cellular cardiology |
Medium |
15623437
|
| 2005 |
Targeted deletion of mek5 in mice results in embryonic lethality at ~E10.5 with abnormal cardiac development, decreased proliferation and increased apoptosis. In mek5-/- MEFs, MEK5 is required for ERK5 activation and for MEF2 transcriptional activity; MEK5 loss sensitizes cells to sorbitol-induced caspase-3 activation without affecting cell cycle progression. |
Knockout mice, MEF analysis, ERK5 kinase assays, caspase activity assays, MEF2 reporter assays |
Molecular and cellular biology |
High |
15601854
|
| 2005 |
The MEK5-ERK5 cascade is activated in biliary epithelial cells of polycystic kidney (PCK) rats, driving aberrant proliferation; siRNA knockdown of MEK5 significantly inhibits this hyperproliferation, while MEK1/2 inhibitors (PD98059, U0126) are less effective, establishing MEK5-ERK5 as the primary proliferative pathway in biliary dysgenesis. |
siRNA knockdown, kinase phosphorylation assays, proliferation assays, pharmacological inhibitors |
The American journal of pathology |
Medium |
15631999
|
| 2005 |
In Xenopus, MEK5-ERK5 is required for neural differentiation downstream of SoxD and upstream of Xngnr1 (a proneural gene); morpholino knockdown of ERK5 or MEK5 reduces head structure and inhibits neural differentiation, and forced MEK5-ERK5 activation alone is sufficient to induce neural differentiation. |
Morpholino antisense knockdown, constitutively active MEK5 expression, in vivo Xenopus assays |
EMBO reports |
High |
16179948
|
| 2007 |
MEKK2 and MEK5 PB1 domains form a front-to-back heterodimer via basic (MEKK2) and acidic (MEK5) surfaces; a C-terminal 34-amino-acid extension of the MEK5 PB1 domain encodes an ERK5 docking site required for MEK5 activation of ERK5. MEKK2 in its quiescent state preferentially binds MEK5; upon activation, MEKK2 also binds MKK7 via the acidic cluster of its PB1 domain to activate JNK. |
Domain interaction mapping, mutagenesis, co-immunoprecipitation, kinase assays |
Molecular and cellular biology |
High |
17452462
|
| 2007 |
NMR solution structure of MEKK3 PB1 domain reveals a ubiquitin fold with cis/trans prolyl isomerization at Gln38-Pro39; MEKK3 PB1 binds MEK5 PB1 with Kd ~10^-8 M, with Lys7 and Arg5 of the basic cluster being critical for MEK5 PB1 interaction. |
NMR structure determination, backbone dynamics, mutagenesis, binding affinity measurement |
Biochemistry |
High |
17985933
|
| 2008 |
Constitutively active MEK5α inhibits ERK5 SUMOylation (at K6/K22) independently of its kinase activity but dependent on MEK5-ERK5 physical association, thereby preventing Ubc9/PIAS1-mediated SUMOylation that suppresses ERK5 transcriptional activity; H2O2 and high glucose induce ERK5 SUMOylation and reduce its transcriptional activity. |
CA-MEK5α transgenic mice, SUMOylation-site mutants (K6R/K22R), siRNA-PIAS1, DN-Ubc9, cardiac function assays |
Circulation research |
High |
18467627
|
| 2008 |
Pharmacological inhibitors BIX02188 and BIX02189 inhibit purified MEK5 enzymatic activity and selectively block ERK5 phosphorylation without affecting ERK1/2 phosphorylation in sorbitol-stimulated cells; they also inhibit MEF2C transcriptional activation downstream of MEK5/ERK5. |
In vitro kinase assay with purified MEK5, cell-based ERK5/ERK1/2 phosphorylation assays, MEF2C reporter assay |
Biochemical and biophysical research communications |
High |
18834865
|
| 2008 |
MEK5-BMK1 (ERK5), but not MEK1-ERK1/2, mediates fluid shear stress inhibition of TNF-induced JNK activation in endothelial cells; selective MEK5 inhibitor BIX02188 completely reverses flow-mediated inhibition of JNK, while MEK1/2-selective concentrations of PD184352 have no effect. |
Pharmacological inhibitors at selective concentrations, shear stress apparatus, JNK activation assays |
Biochemical and biophysical research communications |
Medium |
18358237
|
| 2008 |
MEK5/ERK5 activation promotes an epithelial-to-mesenchymal transition (EMT) phenotype in breast cancer cells, with upregulation of vimentin, SNAI2 (slug), ZEB1, and N-cadherin, and downregulation of E-cadherin and keratins; shRNA targeting ERK5 reverses MEK5-mediated EMT gene expression. |
MEK5 overexpression, proteomics (2D-gel/LC-MS/MS), ERK5 shRNA knockdown, immunofluorescence |
Breast cancer research : BCR |
Medium |
19087274
|
| 2008 |
MEK5-ERK5 regulates thymocyte apoptosis but not positive selection; retroviral dominant-negative MEK5 in developing thymocytes increases apoptosis while constitutively active MEK5 reduces it; ERK5 activity correlates with Nur77 family member levels (but not Bim) as effectors of thymocyte apoptosis. |
Retroviral expression of DN/CA MEK5 in thymocytes, apoptosis assays, Nur77/Bim expression analysis |
The EMBO journal |
Medium |
18548009
|
| 2009 |
MEK5/ERK5 signaling downstream of VEGF induces Id1 and suppresses thrombospondin-1 (TSP1) expression to promote angiogenesis; Epac/Rap1 antagonizes this by suppressing Id1 and inducing TSP1, establishing MEK5 as a pro-angiogenic component controlling Id1/TSP1 balance. |
MEK5 knockdown/overexpression, TSP1 and Id1 expression assays, in vivo angiogenesis assay, Epac/Rap1 activation |
Blood |
Medium |
19710505
|
| 2009 |
Constitutive MEK5/ERK5 activation strongly inhibits endothelial cell migration and increases focal contact number and size via decreased expression of p130Cas (a key regulator of focal contact turnover); this results in increased cell rigidity and reduced motility. |
Retroviral CA-MEK5 expression, migration assays, focal contact imaging, p130Cas expression analysis |
The Journal of biological chemistry |
Medium |
19605361
|
| 2009 |
MEK5 and ERK5 are required for the pro-myogenic actions of IGF-2; dominant-negative MEK5 blocks IGF-2-induced myogenesis and dominant-negative ERK5 prevents nuclear localization of ERK5-GFP upon MEK5 activation; constitutively active MEK5 rescues defects caused by antisense Igf2. |
CA/DN MEK5 expression, ERK5-GFP live imaging, kinase activity assays, myogenic reporter assays |
Journal of cell science |
Medium |
19654213
|
| 2011 |
MEK5 is activated by laminar shear stress in human dermal microvascular endothelial cells, activates ERK5, and induces KLF4 expression (in an ERK5-dependent manner); MEK5/ERK5/KLF4 signaling reduces endothelial inflammatory responses to TNF, in part mediated by KLF4. |
Laminar shear stress, constitutively active MEK5 expression, siRNA knockdown of ERK5 and KLF4, Western blotting, microarray |
Microcirculation (New York, N.Y. : 1994) |
Medium |
21166929
|
| 2014 |
XIAP directly interacts with MEKK2/3 and competes with PB1 domain-mediated binding to MEK5. XIAP and cIAP1 conjugate predominantly K63-linked ubiquitin chains to MEKK2 and MEKK3, which directly impedes MEK5-ERK5 interaction in a trimeric complex, leading to ERK5 inactivation; loss of XIAP or cIAP1 causes ERK5 hyperactivation and promotes myoblast differentiation via MEKK2/3-ERK5. |
Co-immunoprecipitation, ubiquitination assays, ubiquitin linkage analysis, XIAP/cIAP1 knockdown/knockout, myoblast differentiation assay |
The EMBO journal |
High |
24975362
|
| 2014 |
miR-143 directly represses MAP2K5 mRNA, modulating MAP2K5-ERK5 signaling during adipogenic differentiation of adipose-derived stromal cells; the stage-specific effect of miR-143 on adipogenesis is dependent on MAP2K5 suppression. |
miRNA overexpression, luciferase reporter assay for direct targeting, knockdown/overexpression of MAP2K5 |
Scientific reports |
Medium |
24448661
|
| 2017 |
YAP promotes myogenic differentiation via MEK5-ERK5 by activating the Abl/Src/MEKK3/MEK5/ERK5 cascade; co-immunoprecipitation shows YAP interacts with MEKK3 and ERK5; site-directed mutagenesis of MEKK3 Y181F (disrupting the PPGY/YAP interaction motif) inhibits MEK5/ERK5 activation and myogenic differentiation. |
Co-immunoprecipitation, constitutively active MEK5 expression, site-directed mutagenesis, inhibitor studies, myogenic differentiation assays |
FASEB journal |
Medium |
28356344
|
| 2018 |
MAP2K5 variants A321T and M367T (located in the kinase domain) consistently phosphorylate ERK5 at Ser731+Thr733 or Ser496, promoting ERK5 nuclear translocation and altering downstream gene expression, resulting in thyroid epithelial cell malignant transformation. |
Functional study of kinase domain variants, ERK5 phosphorylation assays, nuclear translocation assays, cell transformation assays |
International journal of cancer |
Medium |
30132833
|
| 2018 |
KRAS suppression-induced MYC degradation is antagonized by an ERK1/2-inhibition-induced feedforward mechanism involving EGFR and SRC leading to ERK5 (via MEK5) activation and phosphorylation of MYC at S62, preventing its degradation; concurrent ERK1/2 and ERK5 inhibition causes synergistic MYC loss and PDAC growth suppression. |
Kinome-wide proteomics screen, high-throughput MYC degradation screen, ERK5/MEK5 inhibitors, phospho-MYC S62 assays, PDAC cell growth assays |
Cancer cell |
High |
30423298
|
| 2019 |
Resistance to ERK inhibitors (SCH772984) and BRAF/MEK inhibitors in melanoma involves activation of the IGF1R-MEK5-ERK5 signaling pathway, which counteracts inhibition of ERK1/2 activation; IGF1R inhibition blocks ERK5 activation in resistant cells and reduces growth in 3D spheroids and in vivo. |
Drug-resistant cell line generation, ERK5/ERK1/2 phosphorylation assays, IGF1R inhibition, 3D spheroid assays, xenograft models |
Cancer research |
Medium |
30833419
|
| 2019 |
MEK5 knockdown in prostate cancer cells impairs phosphorylation of the catalytic subunit of DNA-PK at Ser2056 in response to ionizing radiation or etoposide, delays resolution of γH2AX and 53BP1 foci, and compromises nonhomologous end joining (NHEJ) repair, sensitizing cells to genotoxic stress. |
MEK5 siRNA knockdown, DNA-PK phosphorylation assays, γH2AX/53BP1 foci imaging, NHEJ cell-based assay, clonogenic survival, xenograft experiments |
Oncogene |
High |
31980741
|
| 2020 |
The MEK5-ERK5 axis controls lipid metabolism in small-cell lung cancer, including the mevalonate/cholesterol synthesis pathway; depletion of MEK5/ERK5 perturbs lipid metabolism pathways and sensitizes SCLC cells to statin treatment. |
MEK5/ERK5 knockdown, transcriptomics, lipidomics, pharmacological inhibition, in vitro and in vivo growth assays |
Cancer research |
Medium |
31969375
|
| 2020 |
MEK5/ERK5 signaling mediates IL-4-induced M2 macrophage differentiation through regulation of c-Myc expression; ERK5 activation is required for M2 marker induction (Arg-1, Ym-1, Fizz-1) via c-Myc, independently of STAT3 or STAT6 phosphorylation, confirmed by myeloid-specific Erk5 knockout mice. |
MEK5 inhibitor, ERK5 inhibitor, myeloid-specific Erk5 conditional knockout (LysMcre/Erk5f/f), STAT3/6 phosphorylation assays, c-Myc expression analysis |
Journal of leukocyte biology |
High |
32745297
|
| 2020 |
The MEKK3-MEK5-ERK5 kinase cascade is required for basal mitochondrial degradation (independent of exogenous damage); genetic or pharmacological inhibition of MEK5 or ERK5 increases mitochondrial content by reducing lysosome-mediated mitochondrial degradation, without affecting bulk autophagy, PINK1-Parkin mitophagy, or mitochondrial biogenesis. |
Genetic inhibition (CRISPR/knockout), pharmacological inhibitors, mitochondrial content quantification, lysosome-mediated degradation assays |
Cell death discovery |
Medium |
33101709
|
| 2021 |
MEK5 inhibition in neuronal cells reduces p62 levels and increases LC3-II/LC3-I ratio (autophagy activation) in an mTOR- and ERK5-independent manner; MEK5 inhibition alleviates TDP-43 mislocalization and cell death in TDP-43-expressing neuronal cells, identifying MEK5 as a novel autophagy modulator. |
MEK5 inhibitor (BIX02188), autophagy markers (p62, LC3), mTOR assays, TDP-43 localization imaging |
Biochemical and biophysical research communications |
Medium |
31005259
|
| 2021 |
The Hedgehog-GLI pathway regulates MEK5 and ERK5 expression in melanoma: GLI1 binds a non-canonical GLI consensus sequence at the MAPK7 (ERK5) promoter (confirmed by chromatin immunoprecipitation), and ERK5 is required for Hedgehog-GLI-dependent melanoma cell proliferation. |
Chromatin immunoprecipitation, GLI1 genetic inhibition (Patched-1 knockdown), ERK5 inhibition, proliferation assays |
International journal of molecular sciences |
Medium |
34681917
|
| 2021 |
Map2k5 knockout mice display dopaminergic cell loss and decreased tyrosine hydroxylase in the nigrostriatal pathway, with behavioral phenotypes including decreased locomotion, coordination defects, and impaired prepulse inhibition, establishing MAP2K5 as a regulator of dopaminergic neuron survival in vivo. |
Targeted Map2k5 knockout mouse model, behavioral testing, immunohistochemistry for tyrosine hydroxylase |
Frontiers in aging neuroscience |
Medium |
34168549
|
| 2025 |
MEK5-ERK5 activates the Hedgehog-GLI signaling pathway in melanoma: constitutively active MEK5 (MEK5DD) potentiates GLI transcriptional activity and increases GLI1/GLI2 protein levels; ERK5 silencing reduces GLI1/GLI2 mRNA and protein and inhibits GLI transcriptional activity; combined GLI and MEK5 inhibitors more effectively reduce melanoma spheroid growth. |
ERK5 shRNA, MEK5/ERK5 pharmacological inhibitors (JWG-071, AX15836, GW284543, BIX02189), MEK5DD overexpression, GLI luciferase reporter assay, 3D spheroid assays |
Cellular oncology |
Medium |
39998753
|
| 2025 |
MAPKi/ERK5i co-inhibition in NRAS-mutant melanoma induces sustained G1 cell cycle arrest by suppressing Cyclin D1 and CDK4; forced expression of Cyclin D1 and CDK4 rescues cell cycle progression, identifying Cyclin D/CDK4 as the key mediators of the combined MEKi/ERK5i anti-proliferative effect. |
Transcriptome analysis, MEKi/ERK5i pharmacological inhibitors, Cyclin D1/CDK4 forced expression rescue, cell cycle analysis |
Cell death & disease |
Medium |
41053077
|
| 2025 |
RBM39 (a splicing factor) maintains full-length MEK5 mRNA splicing; RBM39 knockdown causes mis-splicing of MEK5, generating aberrant isoforms with exon loss that lack kinase function and undergo proteasomal degradation, thereby inhibiting MM cell survival. Full-length MEK5 activity maintains MM cell survival via p65/NF-κB. |
RBM39 knockdown, indisulam-mediated RBM39 degradation, splicing analysis, MEK5 isoform characterization, proteasome inhibition, p65 activity assays |
Blood advances |
Medium |
40048740
|