| 1997 |
SAPK3/p38γ is activated by SAPKK3 (MKK6) in vitro and in cells in response to cellular stresses, IL-1, and TNF. SAPKK3 is the specific upstream activator induced under these conditions. Unlike SAPK2/p38α, SAPK3/p38γ is not inhibited by SB203580. SAPK3/p38γ phosphorylates ATF2 at Thr69, Thr71, and Ser90 (whereas SAPK2 only phosphorylates Thr69 and Thr71), and also phosphorylates Elk-1 and SAP1, but is far less effective than SAPK2 at activating MAPKAP kinase-2 and MAPKAP kinase-3. |
In vitro kinase assay, co-transfection with MKK6 in mammalian cells, substrate phosphorylation mapping, pharmacological inhibition with SB203580 |
The EMBO journal |
High |
9029150
|
| 1996 |
ERK6/p38γ is activated by tyrosine phosphorylation in transfected 293 cells, producing 46- and 56-kDa forms that phosphorylate myelin basic protein. Overexpression of wild-type ERK6 enhances C2C12 myoblast differentiation to myotubes, while the kinase-inactive Y185F mutant inhibits differentiation, without effects on proliferation. |
Transfection in 293 cells, kinase assay with myelin basic protein, overexpression and dominant-negative in C2C12 differentiation assay |
Proceedings of the National Academy of Sciences of the United States of America |
High |
8633070
|
| 1999 |
Crystal structure of doubly phosphorylated (active) p38γ in complex with an ATP analog was determined by X-ray crystallography. Phospho-Thr183 forms hydrogen bonds with five basic amino acids inducing an interdomain rotation. The activation-loop conformation of active p38γ is nearly identical to activated ERK2. Unlike ERK2, activated p38γ exists as a monomer in both crystal and solution. |
X-ray crystallography, solution studies |
Structure (London, England : 1993) |
High |
10508788
|
| 1999 |
Active p38γ exhibits basal ATPase activity independent of a substrate; addition of phosphoacceptor substrate increases kcat/Km 20-fold. AMP-PCP is competitive with ATP and non-competitive with phosphoacceptor substrate. The affinity label FSBA binds stoichiometrically at Lys-56 in the ATP site of both phosphorylated and unphosphorylated p38γ, but AMP-PCP protects only activated p38γ from FSBA inactivation, indicating AMP-PCP does not bind unphosphorylated p38γ. |
In vitro ATPase assay, competitive inhibition kinetics, affinity labeling with FSBA, site identification |
FEBS letters |
High |
10567720
|
| 2000 |
Activation of the MKK6-p38γ cascade (but not other p38 isoforms) is required for γ-irradiation-induced G2 cell cycle arrest. This pathway is dependent on ATM and leads to activation of Chk2 (Cds1). Dominant-negative alleles of MKK6 or p38γ allow cells to escape DNA damage-induced G2 delay. |
Dominant-negative overexpression, epistasis analysis with ATM and Chk2, cell cycle profiling after γ-irradiation |
Molecular and cellular biology |
High |
10848581
|
| 2003 |
Xp38γ/SAPK3 (Xenopus ortholog) promotes meiotic G2/M transition in Xenopus oocytes. Constitutively active MKK6 activates p38γ as the predominant p38 isoform in oocytes; co-expression induces maturation without progesterone. Xp38γ phosphorylates and activates Cdc25C, with Ser205 identified as a major phosphorylation site. |
Xenopus oocyte overexpression, kinase assay on Cdc25C, phosphorylation site mapping, kinase-dead mutant epistasis |
The EMBO journal |
High |
14592973
|
| 2004 |
SAPK3/p38γ binds through its C-terminal PDZ-binding motif to the third PDZ domain of SAP90/PSD-95 and phosphorylates it at Thr287 and Ser290 in vitro, and at Ser290 in cells under stress. Phosphorylation requires PDZ-domain binding; disrupting this interaction with a cell-permeant Tat fusion peptide abolishes phosphorylation. p38γ co-localizes and co-immunoprecipitates with SAP90 from brain synaptic junctional preparations. |
In vitro kinase assay, phosphorylation site mapping, PDZ domain binding assay, co-IP from brain fractions, Tat peptide disruption, confocal co-localization in neurons |
The Biochemical journal |
High |
14741046
|
| 2005 |
SAPK3/p38γ-catalyzed phosphorylation of SAP97/hDlg triggers its dissociation from GKAP, releasing SAP97 from the cytoskeleton. This regulates the integrity of intercellular junctional complexes and cell shape/volume in response to osmotic stress. |
In vitro kinase assay, co-IP, osmotic stress treatment, phosphorylation-dependent protein complex analysis |
The EMBO journal |
High |
15729360
|
| 2005 |
K-Ras activates p38γ by inducing its expression without increasing its phosphorylation. Unphosphorylated p38γ promotes Ras transformation through increased complex formation with ERK proteins. Depletion of p38γ suppresses K-Ras transformation in rat intestinal epithelial cells. |
shRNA depletion, co-immunoprecipitation of p38γ-ERK complex, Ras transformation assay, expression analysis |
The Journal of biological chemistry |
Medium |
15851477
|
| 2007 |
p38α phosphorylation depletes p38γ protein via c-Jun-dependent ubiquitin-proteasome pathways, acting as a gatekeeper. Active p38α increases c-Jun phosphorylation and AP-1 activation, whereas active p38γ suppresses c-Jun phosphorylation and AP-1 and is itself degraded when p38α is activated. This cross-regulation controls Ras transformation and stress response. |
MKK6-p38 fusion (constitutively active) constructs, AP-1 reporter assay, proteasome inhibitor treatment, co-expression studies |
The Journal of biological chemistry |
Medium |
17724032
|
| 2009 |
p38γ is essential for endurance exercise-induced mitochondrial biogenesis and angiogenesis in skeletal muscle, operating through a p38γ-PGC-1α regulatory axis. Muscle-specific deletion of p38γ (but not p38α or p38β) abolishes contractile activity-dependent Pgc-1α and Vegf transcription. Gene transfer of dominant-negative p38γ blocked motor-nerve-stimulation-induced Pgc-1α transcription. |
Muscle-specific gene deletion in mice, motor nerve stimulation, gene transfer with dominant-negative constructs, real-time PCR and microarray |
PloS one |
High |
19936205
|
| 2009 |
p38γ (but not p38α) mediates oncogenic Ras-induced senescence by phosphorylating p53 at Ser33, thereby stimulating p53 transcriptional activity. shRNA silencing of p38γ abrogates Ras-induced senescence; constitutive activation of p38γ causes premature senescence. |
shRNA knockdown, constitutively active p38γ overexpression, p53 phosphorylation assay, senescence assay |
The Journal of biological chemistry |
Medium |
19251701
|
| 2010 |
p38γ cooperates with c-Jun as both an activator and a cofactor: activated c-Jun recruits p38γ into the MMP9 promoter to induce its trans-activation and cell invasion. p38γ requires phosphorylation and its C-terminus to bind c-Jun; both are required for MMP9 trans-activation. |
ChIP, co-IP, promoter reporter assay, invasion assay, dominant-negative and overexpression studies |
The Journal of biological chemistry |
Medium |
20231272
|
| 2010 |
PTPH1 is a specific phosphatase for p38γ through PDZ-mediated binding. PTPH1 dephosphorylates p38γ and cooperates with it in Ras oncogenesis. Ras increases both p38γ and PTPH1 expression, and there is co-overexpression of p38γ and PTPH1 in primary colon cancer. |
Yeast two-hybrid, co-IP in vitro and in vivo, PDZ-binding domain analysis, Ras transformation assay |
Cancer research |
Medium |
20332238
|
| 2010 |
Loss of p38γ in HeLa cells causes multipolar spindle formation and chromosome misalignment, inducing M-phase arrest followed by cell death. p38γ is required for normal kinetochore localization of Polo-like kinase 1 (Plk1), and p38 MAPKs are activated at kinetochores and spindle poles throughout mitosis. |
siRNA knockdown, live-cell imaging, immunofluorescence of mitotic structures and kinetochore proteins |
Journal of cell science |
Medium |
21172807
|
| 2010 |
In response to hyperosmotic stress, p38γ in the nucleus increases its association with nuclear hDlg, causing dissociation of hDlg-PSF complexes and hDlg-RNA dissociation, independently of p38γ kinase activity. This suggests a non-catalytic scaffolding role for p38γ in regulating mRNA processing/transcription. |
Co-IP, subcellular fractionation, osmotic stress treatment, kinase-dead mutant analysis |
Journal of cell science |
Medium |
20605917
|
| 2011 |
p38γ promotes breast cancer cell motility and metastasis by controlling expression of RhoC GTPase through modulation of RhoC ubiquitination. |
siRNA knockdown, overexpression, ubiquitination assay, migration/invasion assay, in vivo metastasis model |
Cancer research |
Medium |
21862636
|
| 2012 |
p38γ is specifically activated by topoisomerase II drugs (not paclitaxel) in breast cancer cells; activated p38γ phosphorylates and stabilizes Topo IIα protein, enhancing growth inhibition by Topo II drugs. p38γ activity is necessary and sufficient for Topo IIα expression. |
In vitro kinase assay, overexpression and knockdown, protein stability assay, cell viability assay |
The Journal of biological chemistry |
Medium |
21878638
|
| 2012 |
p38γ is selectively activated by tamoxifen treatment; it phosphorylates ERα at Ser-118 and stimulates c-Jun transcription, switching ER signaling from classical (ERE) to nonclassical (AP-1) pathway. ERα phosphorylation at Ser-118 is required for ER to bind both p38γ and c-Jun, promoting ER relocation from ERE to AP-1 promoter sites. |
Kinase assay, co-IP, ChIP, ERE/AP-1 reporter assay, site-directed mutagenesis (Ser-118) |
The Journal of biological chemistry |
Medium |
22399296
|
| 2012 |
p38γ phosphorylates its specific phosphatase PTPH1 at Ser-459 through PDZ-mediated complex formation in vitro and in vivo. Ser-459 phosphorylation is directly regulated by Ras signaling and is important for Ras, p38γ, and PTPH1 oncogenic activity. |
Unbiased proteomic analysis, in vitro kinase assay, phospho-site-specific mutagenesis (Ser-459), co-IP, genetic and pharmacological epistasis |
The Journal of biological chemistry |
High |
22730326
|
| 2012 |
p38γ and p38δ maintain steady-state levels of TPL2 kinase in macrophages and dendritic cells, enabling ERK1/2 activation after TLR4 stimulation by LPS. Loss of p38γ/δ blocks ERK1/2 activation and alters cytokine production profile. |
p38γ/δ double knockout mice, LPS stimulation, immunoblotting for TPL2 and phospho-ERK1/2, cytokine ELISA, bone marrow transplant chimeras |
Proceedings of the National Academy of Sciences of the United States of America |
High |
22733747
|
| 2014 |
The PTPN3 (PTPH1)-p38γ complex structure was determined by hybrid methods (X-ray crystallography, SAXS, chemical cross-linking/MS). The E-loop of PTPN3's phosphatase domain defines substrate specificity toward fully activated p38γ. The PDZ domain of PTPN3 stabilizes the active-state complex via interaction with the PDZ-binding motif of p38γ, alleviating PTPN3 autoinhibition and enabling efficient tyrosine dephosphorylation of p38γ. |
X-ray crystallography, SAXS, chemical cross-linking coupled to mass spectrometry, PDZ-binding assay |
Science signaling |
High |
25314968
|
| 2016 |
Crystal structure of the PDZ domain of PTPN4 bound to the C-terminus of p38γ was determined. The p38γ C-terminus binds the PDZ domain with highest affinity among endogenous PTPN4 partners; this binding activates PTPN4 by abolishing its catalytic autoinhibition, enabling efficient dephosphorylation of the p38γ activation loop. |
X-ray crystallography, co-IP, PDZ binding affinity measurements, phosphatase activity assay |
The Journal of biological chemistry |
High |
27246854
|
| 2016 |
p38γ and p38δ promote cardiac hypertrophy by phosphorylating DEPTOR, leading to its proteasomal degradation and consequent mTOR activation. Hearts from mice lacking one or both kinases have elevated DEPTOR, reduced mTOR activity, and reduced protein synthesis. Cardiac phenotype is rescued by mTOR overactivation, Deptor shRNA knockdown, or cardiomyocyte overexpression of active p38γ/δ. |
Cardiac-specific KO mice, rescue experiments with mTOR activation/Deptor shRNA/active kinase overexpression, in vitro phosphorylation assay, protein stability assay |
Nature communications |
High |
26795633
|
| 2019 |
p38γ acts as a CDK-like kinase, phosphorylating retinoblastoma protein (Rb) at known CDK target residues to promote the G0-to-G1 cell cycle transition. p38γ shares substrate specificity and inhibitor sensitivity with CDK family members. Lack of p38γ or pirfenidone treatment protects against chemically induced liver tumour formation. |
Hepatocyte-specific knockout, partial hepatectomy model, Rb phosphorylation assay, sequence homology and inhibitor sensitivity comparison, pharmacological inhibition |
Nature |
High |
30971822
|
| 2019 |
p38γ interacts with the glycolytic activator PFKFB3 in a KRAS-dependent manner. p38γ phosphorylates PFKFB3 at Ser-467, stabilizing PFKFB3 and promoting its interaction with GLUT2, thereby enhancing aerobic glycolysis. Pancreatic knockout of p38γ decreases p-PFKFB3/PFKFB3/GLUT2 levels, reduces aerobic glycolysis, and inhibits PDAC tumorigenesis. |
Co-IP, in vitro kinase assay with phospho-site mapping (Ser-467), pancreatic KO in KPC mice, glycolysis assays, protein stability assay |
Cancer research |
High |
32580961
|
| 2019 |
p38γ calpastatin as a direct substrate was identified using an analog-sensitive p38γ mutant. Phosphorylation of calpastatin by p38γ impairs its ability to inhibit the protease calpain. p38γ KO mice develop less ventricular hypertrophy after aortic banding, consistent with calpain disinhibition contributing to pathological remodeling. |
Analog-sensitive kinase substrate labeling, affinity purification/mass spectrometry, in vitro phosphorylation-inhibition assay for calpastatin-calpain, cardiac KO with aortic banding |
FASEB journal |
High |
31638431
|
| 2020 |
Imidazole propionate activates p38γ, which acts as a novel kinase for Akt, inducing inhibitory Akt phosphorylation. This leads to inhibitory AMPK phosphorylation, blocking metformin-induced glucose lowering. p38γ kinase activity mediates the inhibitory action of imidazole propionate on metformin. |
In vitro kinase assay showing p38γ phosphorylates Akt, mouse model pretreatment with imidazole propionate, siRNA knockdown of p38γ, AMPK phosphorylation assay |
Cell metabolism |
High |
32783890
|
| 2020 |
p38γ phosphorylates tau at Thr205 (T205) at postsynaptic compartments, inhibiting toxic amyloid-β signals. This phosphorylation event is critical for downstream neuroprotective effects: reconstitution with phosphorylation-deficient tauT205A abolished protection in APP-transgenic mice. |
Gene therapeutic AAV delivery, phospho-site mutagenesis (T205A), memory testing in AD mouse models, genome editing of T205 codon |
Acta neuropathologica |
High |
32725265
|
| 2021 |
p38γ and p38δ contribute to the postnatal cardiac metabolic switch from glycolysis to fatty acid oxidation through inhibitory phosphorylation of glycogen synthase 1 (GYS1), leading to glycogen metabolism inactivation. |
p38γ/δ KO mice, cardiomyocyte-specific overexpression, GYS1 phosphorylation assay, metabolic measurements |
PLoS biology |
High |
34758018
|
| 2022 |
MKK6 deficiency causes compensatory hyperactivation of the MKK3-p38γ/δ pathway, leading to increased mTOR signaling and cardiac hypertrophy. Cardiac hypertrophy in MKK6-KO mice is reverted by knocking out p38γ or p38δ or by rapamycin treatment, placing MKK3-p38γ/δ upstream of mTOR in cardiac hypertrophy. |
MKK6 KO mice, double KO (MKK6/p38γ or MKK6/p38δ), rapamycin treatment, cardiac function measurements |
eLife |
High |
35971771
|
| 2022 |
p38γ-mediated phosphorylation of tau at T205 is essential for seizure protection in epilepsy models. AAV-mediated p38γ activity enhancement reduces seizure susceptibility and ameliorates neuronal deficits; lack of the p38γ-tau-T205 interaction reinstates pathological features. |
AAV gene delivery of p38γ in mouse epilepsy models, phosphorylation-deficient tauT205A mutant, seizure threshold measurement |
Science advances |
High |
36459557
|
| 2023 |
p38γ and p38δ phosphorylate the transcription factor MEF2D at Ser444, and this phosphorylation suppresses MEF2D transcriptional activity. Mutation of MEF2D Ser444 to Ala (non-phosphorylatable) increased transcriptional activity and expression of Nos2 and Il1b mRNA, demonstrating that p38γ/δ govern innate immune responses through MEF2D regulation. |
Phospho-proteomic analysis, in vitro kinase assay, site-directed mutagenesis (S444A), gene expression analysis in p38γ/δ kinase-inactive knock-in mouse macrophages |
eLife |
High |
37458356
|
| 2023 |
p38γ and p38δ regulate TPL2 protein levels posttranscriptionally by two mechanisms: (1) interacting with the TPL2/ABIN2/NF-κB1p105 complex to increase TPL2 protein stability, and (2) regulating TPL2 mRNA translation through modulation of the repressor function of TPL2 3'UTR mediated by aconitase-1 (ACO1). p38δ binds ACO1 and its expression restores TPL2 protein levels. |
Co-IP, mRNA translation assay with 3'UTR reporter, ACO1 overexpression, p38δ rescue in KO cells |
Proceedings of the National Academy of Sciences of the United States of America |
Medium |
35994673
|
| 2023 |
p38γ phosphorylates CARM1 at Ser-595 under oxidative stress, causing CARM1 translocation from nucleus to cytoplasm. Cytoplasmic CARM1 methylates DRP1 and accelerates mitochondrial fission, enhancing ROS production and driving cellular senescence. This creates a positive feedback loop between ROS, p38γ activation, and CARM1 cytoplasmic localization. |
In vitro kinase assay, co-IP, subcellular fractionation, phospho-site specific analysis (S595), mitochondrial dynamics imaging |
Redox biology |
Medium |
39265499
|
| 2023 |
p38γ and p38δ phosphorylate ryanodine receptor 2 (RyR2) and disrupt Kv4.3 channel localization upon activation, promoting sarcoplasmic reticulum calcium leak, Ito current reduction, and action potential duration prolongation, increasing susceptibility to ventricular fibrillation. |
Phosphorylation assays, ion channel electrophysiology, calcium imaging, p38γ/δ KO and activation mouse models |
Nature cardiovascular research |
High |
39196141
|
| 2002 |
SAPK3/p38γ localizes to punctate, non-nuclear structures in cardiac myocytes, distinct from the non-punctate cytosolic/nuclear distribution of p38α/β. Treatment with Leptomycin B (blocking nuclear export) increases nuclear p38α/β but does not alter SAPK3/p38γ localization, suggesting p38γ does not undergo nuclear export-dependent cycling. |
Monoclonal antibody generation, immunofluorescence, confocal microscopy, Leptomycin B treatment |
Journal of molecular and cellular cardiology |
Medium |
11991731
|
| 2016 |
NMR chemical shift perturbation mapping of p38γ reveals intramolecular allosteric networks and information flux between regulatory sites (activation loop, DFG loop, ATP-binding site, docking sites). The network is differentially accessed in different functional states (apo, phosphorylated, ATP-bound), demonstrating that p38γ docking sites are allosterically regulated by active-site state. |
NMR spectroscopy, chemical shift perturbation analysis in multiple states |
Scientific reports |
Medium |
27353957
|
| 2019 |
Inactive p38γ fluctuates on a millisecond timescale between an open ground state and a weakly populated compact excited state (similar to the activated enzyme conformation) involving a molecular switch associated with the DFG loop. This was identified by X-ray crystallography (two molecules in asymmetric unit) and NMR relaxation dispersion. |
X-ray crystallography (inactive apo p38γ), NMR relaxation dispersion measurements |
Biochemistry |
High |
31794659
|
| 2015 |
p38γ stimulates Nanog transcription through c-Jun/AP-1 via multi-protein complex formation, driving cancer stem-like cell expansion in triple-negative breast cancer. |
ChIP, co-IP (multi-protein complex), reporter assay, siRNA knockdown, mammosphere formation assay |
Stem cells (Dayton, Ohio) |
Medium |
26077647
|
| 2017 |
The K-Ras effector p38γ confers resistance to EGFR tyrosine kinase inhibitors by concurrently increasing EGFR transcription (via c-Jun promoter binding) and promoting EGFR dephosphorylation (via activation of PTPH1). Silencing the p38γ/c-Jun/PTPH1 network restores TKI sensitivity in K-Ras mutant cancer cells. |
ChIP, co-IP, siRNA knockdown, kinase inhibitor sensitivity assays, promoter reporter assay |
The Journal of biological chemistry |
Medium |
28739874
|
| 2018 |
p38γ induces EMT in breast cancer cells and augments cancer stem cell populations by inhibiting GATA3 through ubiquitination-dependent proteasomal degradation, which suppresses miR-200b expression, leading to increased Suz12 and EMT. |
Overexpression and siRNA knockdown, ubiquitination assay, miR-200b mimic/inhibitor, proteasome inhibitor treatment |
Biochimica et biophysica acta. Molecular basis of disease |
Medium |
30251680
|
| 2015 |
p38γ promotes β-catenin/Wnt signaling in colon cancer by phosphorylating β-catenin at Ser605, stimulating Wnt transcription. Intestinal epithelial-specific p38γ KO attenuates colitis and inhibits pro-inflammatory cytokine expression and tumorigenesis in a colitis-associated mouse model. |
Intestinal epithelial-specific KO, phosphorylation assay (Ser605), Wnt reporter assay, colitis-associated tumorigenesis model |
Oncogene |
Medium |
25961922
|
| 2003 |
p38γ (ERK6) expression is developmentally regulated in skeletal muscle: mRNA and protein levels increase during differentiation of myoblast cell lines in vitro and during postnatal development in rat hindlimb muscle in vivo, in contrast to p42/p44 MAPK and p38, which do not change. |
Northern blot, immunoblotting during in vitro differentiation and in vivo postnatal development |
Biochemical and biophysical research communications |
Medium |
12788083
|
| 2004 |
MRK (a MAP3K) is a specific upstream activator of p38γ but not p38α after ionizing radiation. MRK depletion reduces IR-induced p38γ activation. Inhibition of p38γ alone by RNAi did not impair IR-induced checkpoints, suggesting MRK controls checkpoint signaling through a p38γ-independent pathway (Chk2-Cdc25A) in parallel to p38γ activation. |
siRNA knockdown of MRK and p38γ, phospho-specific antibody to MRK, Chk2 phosphorylation assay, cell cycle checkpoint analysis |
The Journal of biological chemistry |
Medium |
15342622
|
| 2020 |
In DLB/PD brains and α-synuclein transgenic mice, p38γ is redistributed from synaptic terminals to neuronal cell bodies and colocalizes with α-synuclein aggregates. α-synuclein co-immunoprecipitates with p38γ but not p38α in vitro. In healthy tissue, p38γ localizes to presynaptic terminals where it normally associates with α1-syntrophin. |
Immunohistochemistry, co-immunoprecipitation, immunoblotting, qPCR, subcellular fractionation in human and mouse brain |
Frontiers in neuroscience |
Medium |
32296304
|