| 2002 |
PHD3 (EGLN3) hydroxylates specific proline residues in HIF-1α within a conserved LXXLAP sequence motif; the hydroxylacceptor proline itself is the only obligatory residue for this reaction. PHD2 shows highest specific activity toward the primary hydroxylation site, while PHD3 shows restricted substrate specificity. |
In vitro prolyl hydroxylase assay with mutant HIF-1α peptides; sequence analysis |
The Journal of biological chemistry |
High |
12181324
|
| 2004 |
PHD3 contributes in a non-redundant manner to oxygen-dependent regulation of both HIF-1α and HIF-2α subunits; PHD isoforms show specificity for different prolyl hydroxylation sites within HIF-α subunits and a degree of selectivity between HIF-1α and HIF-2α. |
siRNA-mediated knockdown of individual PHD isoforms followed by measurement of HIF-α protein levels in multiple cell types under various culture conditions |
The Journal of biological chemistry |
High |
15247232
|
| 2004 |
PHD3 interacts with the cytosolic chaperonin TRiC (TCP-1 ring complex), identified by co-purification and mass spectrometry, suggesting PHD3 is a TRiC substrate and that TRiC may regulate PHD3 activity. |
Co-purification of PHD3 from cell extracts followed by mass spectrometry identification of TRiC subunits |
FEBS letters |
Medium |
15251459
|
| 2005 |
EglN3 (PHD3) acts downstream of c-Jun and is specifically required among EglN family members for neuronal apoptosis when NGF becomes limiting; EglN3 proapoptotic activity is feedback-inhibited by succinate (a product of SDH), placing EglN3 in a pathway linking SDH activity to developmental apoptosis. |
Genetic epistasis in sympathetic neuronal progenitor cells: selective EglN3 knockdown, NGF withdrawal apoptosis assay, succinate supplementation inhibition |
Cancer cell |
High |
16098468
|
| 2005 |
A functional hypoxia response element (HRE) located in the first intron of the EGLN3 gene (12 kb downstream of transcription start) binds HIF in vivo and drives HIF-dependent transcriptional induction of EGLN3 under hypoxia, establishing a negative feedback loop. |
Bioinformatics HRE identification, reporter gene assays, chromatin immunoprecipitation (ChIP) |
The Biochemical journal |
High |
15823097
|
| 2006 |
PHD3 physically interacts with the novel WD-repeat scaffold protein Morg1 (MAPK organizer 1); co-expression of Morg1 with PHD3 decreases HIF-mediated reporter gene activity, and siRNA knockdown of either Morg1 or PHD3 increases HIF-1 activity. Both proteins co-localize in the cytoplasm and nucleus. |
Yeast two-hybrid screen, in vitro and in vivo co-immunoprecipitation, confocal microscopy co-localization, HIF reporter assay with siRNA knockdown |
The Journal of biological chemistry |
High |
16407229
|
| 2007 |
PHD3 interacts with the zipper II domain of ATF-4 and hydroxylates ATF-4 within a novel oxygen-dependent degradation (ODD) domain; siRNA knockdown of PHD3 (but not PHD2) stabilizes ATF-4 under normoxia, identifying ATF-4 as a PHD3-specific substrate independent of pVHL. |
Co-IP, siRNA knockdown of PHD isoforms, mutational analysis of ATF-4 prolyl residues (5-proline mutations stabilize ATF-4), PHD inhibitor treatment |
Blood |
High |
17684156
|
| 2007 |
EGLN3 levels increase during C2C12 skeletal myoblast differentiation; EGLN3 interacts with and stabilizes myogenin protein, while VHL associates with and destabilizes myogenin via the ubiquitin-proteasome pathway. Overexpression of EGLN3 reverses VHL-mediated myogenin degradation, revealing a novel HIF-independent role for EGLN3 in myogenic differentiation. |
siRNA/antisense knockdown of EGLN3, co-immunoprecipitation of EGLN3 with myogenin, ubiquitination assay, EGLN3 overexpression rescue of VHL-mediated myogenin degradation |
The Journal of biological chemistry |
High |
17344222
|
| 2007 |
Catalytically active human PHD3 was expressed and purified from E. coli; the enzyme hydroxylates Pro567 (a novel site) in addition to the canonical Pro564 of HIF-1α. PHD3 activity is inhibited by Zn2+, desferrioxamine, and imidazole, consistent with its iron- and 2-oxoglutarate-dependent dioxygenase mechanism. |
Heterologous expression in E. coli, Ni-affinity chromatography purification, in vitro hydroxylation assay with HIF-1α-derived peptide, mass spectrometry verification of hydroxylation |
Protein expression and purification |
High |
17434750
|
| 2008 |
PHD3 forms oxygen-dependent subcellular aggregates under normoxia in an activity-dependent manner; aggregates contain 26S proteasome components, chaperones, and ubiquitin (aggresome-like features); forced expression of active PHD3 induces protein aggregation and apoptosis. Aggregate formation depends on microtubular integrity and is reversed by hypoxia or PHD3 catalytic inactivation. |
Fluorescence microscopy of PHD3-GFP aggregates, fractionation, co-localization with proteasome/ubiquitin markers, pharmacological inhibition, active-site mutant comparison |
Molecular biology of the cell |
Medium |
18337469
|
| 2008 |
PHD3 knockout mice (PHD3−/−) show reduced apoptosis in superior cervical ganglion (SCG) neurons, increased SCG and adrenal medulla cell numbers, and hypofunctional sympathoadrenal development. Genetic intercrossing with HIF-1α+/− and HIF-2α+/− mice demonstrates a PHD3–HIF-2α interaction (but not HIF-1α) in sympathoadrenal development. |
PHD3−/− mouse generation, neuronal apoptosis assay (cultured SCG neurons), genetic epistasis (PHD3−/− × HIF-1α+/−; PHD3−/− × HIF-2α+/−), sympathoadrenal functional assays |
Molecular and cellular biology |
High |
18332118
|
| 2008 |
The kinesin KIF1Bβ acts downstream of EglN3 in the NGF-withdrawal apoptotic pathway; KIF1Bβ is both necessary and sufficient for neuronal apoptosis when NGF becomes limiting, placing it genetically downstream of EglN3. |
Unbiased shRNA screen, epistasis analysis in neuronal progenitor cells with EglN3 and KIF1Bβ knockdown/overexpression, apoptosis assays |
Genes & development |
High |
18334619
|
| 2008 |
Siah2 E3 ligase preferentially targets PHD3 for degradation because PHD3 lacks the N-terminal extension present in PHD1/PHD2; deletion of this extension from PHD1/PHD2 renders them susceptible to Siah2-mediated degradation. PHD3 homo- and hetero-multimerizes with other PHDs; the lower-molecular-mass PHD3 form has higher specific activity toward HIF-1α hydroxylation and co-localizes with Siah2. |
Co-immunoprecipitation, size-exclusion fractionation, in vitro HIF-1α hydroxylation assay with different PHD3 complexes, N-terminal deletion mutagenesis of PHD1/PHD2 |
The Biochemical journal |
High |
16958618
|
| 2009 |
EGLN3 directly interacts with the β2-adrenergic receptor (β2AR) and hydroxylates it at proline-382 and proline-395, enabling recognition and ubiquitylation by pVHL, leading to proteasomal degradation of β2AR. Hypoxia reduces receptor hydroxylation, attenuating receptor degradation, thereby expanding the functional scope of prolyl hydroxylation beyond HIF. |
Co-IP of EGLN3 with β2AR, mass spectrometry identification of hydroxylation sites, mutagenesis of proline residues, pVHL ubiquitylation assay, hypoxic condition experiments, endogenous receptor abundance measurement |
Science signaling |
High |
19584355
|
| 2009 |
Phd3 loss in mice exacerbates HIF activation, hepatic steatosis, dilated cardiomyopathy, and premature mortality caused by Phd2 loss alone, demonstrating that Phd3 participates in a HIF-regulatory feedback loop in vivo and can partially compensate for Phd2. |
Phd2/Phd3 double-knockout mice, HIF target gene expression analysis, histopathology |
Molecular and cellular biology |
High |
19720742
|
| 2010 |
EGLN3 prolyl hydroxylase activity is required to suppress canonical NF-κB signaling during skeletal myoblast differentiation; catalytically inactive EGLN3 fails to inhibit NF-κB, and NF-κB activation (via DMOG, hypoxia, or EGLN3 knockdown) blocks myogenic differentiation through a HIF-independent mechanism. |
Pharmacological PHD inhibition (DMOG, DFO, hypoxia), HIF dominant-negative/siRNA (to confirm HIF independence), IκBα dominant-negative, wild-type vs. catalytically-inactive EGLN3 overexpression, NF-κB reporter assay |
The Journal of biological chemistry |
High |
20089853
|
| 2011 |
PKM2 (but not PKM1) is hydroxylated by PHD3 at proline-403/408; this hydroxylation enhances PKM2 binding to HIF-1α and promotes PKM2 coactivator function for HIF-1 target genes. PHD3 knockdown inhibits PKM2 coactivator activity, reduces glucose uptake and lactate production, and increases O2 consumption in cancer cells. |
Mass spectrometry and anti-hydroxyproline antibody identification of PKM2 hydroxylation sites, Co-IP of PHD3/PKM2/HIF-1α, PHD3 knockdown, glucose uptake/lactate/O2 consumption assays, PKM1 vs PKM2 comparison |
Cell |
High |
21620138
|
| 2011 |
PHD3 is uniquely required among PHD isoforms for prolonging neutrophil survival during hypoxia; PHD3-deficient neutrophils show increased apoptosis associated with upregulation of proapoptotic Siva1 and loss of Bcl-xL binding, independent of altered HIF transcriptional activity. In vivo, PHD3-deficient mice show increased neutrophil clearance in acute lung injury and reduced neutrophilic inflammation in colitis. |
Phd3−/− mouse neutrophils, apoptosis assays, Siva1/Bcl-xL expression measurement, HIF transcriptional activity assay, acute lung injury model, colitis model |
The Journal of clinical investigation |
High |
21317538
|
| 2012 |
PHD3 hydroxylates HCLK2 (human CLK-2), an essential component of the ATR/CHK1 signaling pathway; HCLK2 hydroxylation is required for its interaction with ATR and subsequent ATR/CHK1/p53 activation. PHD3 inhibition (pharmacologically with DMOG or genetically) prevents ATR/CHK1/p53 pathway activation and decreases DNA-damage-induced apoptosis. PHD3−/− mice are resistant to ionizing radiation. |
Co-IP of PHD3 with HCLK2 and ATR, DMOG/hypoxia inhibition, PHD3 knockout mice, thymic apoptosis assay, CHK1/p53 phosphorylation western blot |
The Journal of clinical investigation |
High |
22797300
|
| 2012 |
PHD3 acts as a co-activator of NF-κB/p65 signaling in nucleus pulposus cells independently of its hydroxylase activity; PHD3 physically interacts with and co-localizes with p65. PHD3 silencing decreases TNF-α-induced expression of catabolic markers (ADAMTS5, MMP13, COX2) and restores aggrecan/collagen type II expression. |
Co-IP and co-localization of PHD3 with p65, lentiviral shRNA knockdown, NF-κB reporter assay, cytokine gene expression measurement, HRE reporter confirming HIF-independence |
The Journal of biological chemistry |
High |
22948157
|
| 2013 |
EGLN3 specifically interacts with IKKγ (NEMO) and inhibits K63-linked ubiquitination of IKKγ by competing with cIAP1 for IKKγ binding; this suppresses IKK-NF-κB signaling. The effect is independent of EGLN3 hydroxylase activity but requires physical interaction with IKKγ. EGLN1 and EGLN2 do not share this function. |
Co-IP of EGLN3 with IKKγ, ubiquitination assay (K63-linked), EGLN3 catalytic mutant comparison, cIAP1 competition assay, NF-κB reporter assay with EGLN isoform comparison |
Molecular and cellular biology |
High |
23732909
|
| 2013 |
p62/SQSTM1 interacts with PHD3 in normoxic cytosolic aggregates, promotes PHD3 aggregation and degradation under normoxia, and limits PHD3 activity. Under hypoxia, p62 decreases, allowing PHD3 to distribute evenly in cells and interact more with HIF-α. Loss of p62 elevates PHD3 levels and reduces HIF-α via enhanced PHD3–HIF-α interaction. |
Co-IP of p62 with PHD3, siRNA knockdown of p62, fluorescence microscopy of PHD3 localization, HIF-α protein level measurement |
Journal of cell science |
Medium |
23345396
|
| 2013 |
Acute hepatic deletion of Phd3 in mice improves insulin sensitivity and ameliorates diabetes by specifically stabilizing HIF-2α (not HIF-1α), which increases Irs2 transcription and insulin-stimulated Akt activation. Both HIF-2α and Irs2 are required for the metabolic benefit of Phd3 knockout. |
Acute hepatic Phd3 knockout, glucose tolerance/insulin tolerance tests, Akt phosphorylation, shRNA knockdown of HIF-2α and Irs2 (epistasis), comparison with other PHD isoforms |
Nature medicine |
High |
24037093
|
| 2014 |
PHD3 interacts with the endocytic adaptor Eps15 and promotes internalization of EGFR as a scaffolding protein, independent of its hydroxylase activity; loss of PHD3 suppresses EGFR internalization and hyperactivates EGFR signaling to enhance cell proliferation and survival. This is independent of HIF and NF-κB. |
Co-IP of PHD3 with Eps15, EGFR internalization assay, PHD3 siRNA/shRNA knockdown, EGFR phosphorylation measurement, PHD3 catalytic mutant |
Nature communications |
High |
25420589
|
| 2014 |
PHD3-mediated prolyl hydroxylation of nonmuscle actin at proline-307 and proline-322 inhibits actin polymerization and cell motility; PHD3 knockdown increases F-actin assembly and cell migration velocity, while PHD3 overexpression reverses this effect. |
Mass spectrometry identification of actin hydroxylation sites, Co-IP of PHD3 with actin, shRNA knockdown, PHD3 overexpression, F-actin/G-actin fractionation, pharmacological PHD inhibition (DMOG), cell migration assay |
Molecular biology of the cell |
High |
25079693
|
| 2014 |
PHD3 interacts with pyruvate dehydrogenase E1β subunit (PDH-E1β); PHD3 depletion destabilizes the PDH complex (PDC) and decreases cellular PDH activity without affecting PDH subunit expression or E1α phosphorylation status. |
Proteomics (MS) to identify PHD3-interacting proteins, co-IP validation of PHD3–PDH-E1β interaction, PDH activity assay in PHD3-depleted cells and PHD3−/− MEFs, PDH complex stability measurement |
Biochemical and biophysical research communications |
Medium |
25088999
|
| 2014 |
PHD3 stabilizes the tight junction protein occludin by preventing interaction between the E3 ligase Itch and occludin, in a hydroxylase-independent manner; intestinal epithelial-specific Phd3 knockout in mice leads to decreased occludin levels and spontaneous colitis. |
Intestinal epithelial-specific Phd3 knockout mice, Co-IP of PHD3/occludin/Itch, tight junction/permeability assays, hydroxylase-independent PHD3 mutant |
The Journal of biological chemistry |
High |
26124271
|
| 2014 |
PHD3 SUMOylation at a C-terminal cluster of four lysines (by SUMO2/SUMO3) represses HIF-1 transcriptional activity without affecting PHD3 hydroxylase activity or HIF-1α stability, revealing a catalysis-independent mechanism of HIF-1 regulation; hypoxia modulates PHD3 SUMOylation inversely with HIF-1 activation. |
SUMOylation assay, lysine cluster mutagenesis, HIF-1 reporter assay, HIF-1α protein level measurement, hydroxylase activity assay |
Journal of cell science |
Medium |
25380826
|
| 2015 |
PHD3 decreases the half-life of CDK inhibitor p27/CDKN1B under hypoxia via a mechanism involving reduced p27 phosphorylation at serine-10, promoting G1/S cell cycle entry; this effect is HIF-independent and requires intact p27-Ser10. |
PHD3 siRNA/shRNA knockdown, flow cytometry cell cycle analysis, cycloheximide chase for p27 half-life, phospho-specific antibody for p27-S10, p27-S10A mutant, HIF-independence confirmed |
Molecular cancer |
Medium |
26223520
|
| 2016 |
PHD3 hydroxylates acetyl-CoA carboxylase 2 (ACC2) at a proline residue in response to nutrient abundance, activating ACC2 to suppress fatty acid oxidation (FAO); loss of PHD3 prevents ACC2 hydroxylation and enables elevated FAO. Overexpressing PHD3 limits FAO and impedes leukemia cell proliferation. |
PHD3 knockdown/overexpression, ACC2 hydroxylation assay, fatty acid oxidation measurement (isotopic tracing), PHD3-null cancer cell analysis, AML/leukemia proliferation assay |
Molecular cell |
High |
27635760
|
| 2018 |
PHD3 hydroxylates p53 at proline-359, a residue in the p53-DUB binding domain; this hydroxylation regulates p53 interaction with deubiquitinases USP7 and USP10. Inhibiting PHD3 decreases p53 association with USP7/USP10, increases p53 ubiquitination, and rapidly reduces p53 protein levels independent of mRNA. |
Co-IP of PHD3 with p53, mass spectrometry identification of Pro359 hydroxylation, USP7/USP10 interaction assay, ubiquitination assay, mRNA expression control |
Cell reports |
High |
30067985
|
| 2019 |
EglN3 hydroxylates BIM-EL (proapoptotic BH3-only protein); hydroxylated BIM-EL is subsequently bound by VHL, which inhibits ERK-mediated phosphorylation at Ser69, allowing BIM-EL to escape proteasomal degradation and enhance EglN3-induced apoptosis. VHL type 2C mutants fail to bind hydroxylated BIM-EL, linking this pathway to pheochromocytoma pathogenesis. |
Co-IP of BIM-EL with VHL and EglN3, hydroxylation assay, phosphorylation assay (ERK/Ser69), genetic EglN3 inactivation, VHL mutant panel, cisplatin resistance assay, ERK inhibitor rescue |
Proceedings of the National Academy of Sciences of the United States of America |
High |
31375625
|
| 2019 |
In clear cell renal cell carcinoma (ccRCC) cells, PHD3 silencing leads to downregulation of HIF-2α protein and mRNA (opposite to canonical pathway), by reducing HIF2A mRNA stability. This effect is PHD3-specific (other PHD family members have no effect) and cell-type-specific (non-RCC cells show expected HIF-2α increase upon PHD3 knockdown). |
siRNA-mediated PHD3 knockdown, HIF-2α protein/mRNA measurement by immunoblot and qRT-PCR, mRNA stability assay, comparison with PHD1/PHD2 knockdown, forced HIF-2α expression rescue |
The Journal of biological chemistry |
High |
30617181
|
| 2020 |
PHD3 hydroxylates ACC2; in skeletal muscle, ACC2 hydroxylation and AMPK-mediated phosphorylation of ACC2 occur inversely. PHD3-null mice show loss of ACC2 hydroxylation in heart and skeletal muscle, elevated fatty acid oxidation, and enhanced endurance exercise capacity. Skeletal muscle-specific PHD3 loss is sufficient to enhance exercise capacity. |
PHD3 whole-body and skeletal muscle-specific knockout mice, ACC2 hydroxylation measurement, fatty acid oxidation measurement, endurance exercise treadmill assay, AMPK phosphorylation comparison |
Cell metabolism |
High |
32663458
|
| 2020 |
CDC20 binds to a destruction-box (D-box) motif in PHD3 protein and promotes its polyubiquitination and proteasomal degradation via the APC/CDC20 complex, thereby stabilizing HIF-1α and promoting VEGF secretion in hepatocellular carcinoma cells. |
Co-IP of CDC20 with PHD3, ubiquitination assay, genetic ablation and pharmacological inhibition of CDC20, HIF-1α/VEGF measurement, non-degradable PHD3 D-box mutant rescue, xenograft tumor assay |
Cancer letters |
Medium |
33039559
|
| 2021 |
USP9X deubiquitinates EGLN3, preventing its proteasomal degradation; loss of USP9X leads to EGLN3 degradation, reducing the apoptotic KIF1Bβ pathway and promoting cholangiocarcinoma proliferation. |
Co-IP of USP9X with EGLN3, ubiquitination assay, shRNA knockdown of USP9X and EGLN3, xenograft tumor model, KIF1Bβ expression measurement |
Journal of biomedical science |
Medium |
34112167
|
| 2022 |
EGLN3 hydroxylates ERK3, preventing its interaction with LAMP2A and HSC70 (core CMA components), thereby blocking chaperone-mediated autophagy (CMA)-lysosomal degradation of ERK3; inactivation of EGLN3 catalytic activity promotes ERK3 degradation via CMA. |
Co-IP of ERK3 with HSC70 and LAMP2A, EGLN3 catalytically inactive knock-in mice, CMA-lysosome inhibition assay, hydroxylation assay, LAMP2A/ERK3 interaction rescue experiment |
Oncogene |
High |
35124697
|
| 2023 |
MAEA E3 ligase targets PHD3 at lysine-159 to promote K48-linked polyubiquitination and proteasomal degradation of PHD3, thereby stabilizing HIF-1α and upregulating CD133 to promote glioblastoma stemness and temozolomide resistance. |
TMT-based quantitative proteomics, co-IP of MAEA with PHD3, ubiquitination assay (K48-linked), K159 mutagenesis, HIF-1α/CD133 protein level measurement, xenograft tumor assay |
Oncogene |
Medium |
36882523
|
| 2009 |
IFNγ induces PHD3 (but not PHD1 or PHD2) expression in human endothelial cells through a JAK/STAT1-dependent mechanism, as demonstrated by pharmacological inhibition of JAK, siRNA knockdown of STAT1, and chromatin immunoprecipitation showing STAT1 binding to the PHD3 promoter. This induction is independent of HIF-1α. |
qRT-PCR, immunoblotting, JAK inhibitor, STAT1 siRNA knockdown, chromatin immunoprecipitation (ChIP) for STAT1 at PHD3 promoter |
Arteriosclerosis, thrombosis, and vascular biology |
Medium |
19574556
|
| 2010 |
Human PRP19 interacts with PHD3 via its C-terminal WD40 region; interaction is enhanced under hypoxia through PRP19's N-terminal coiled-coil domain. PRP19 overexpression suppresses PHD3-dependent cell death under prolonged hypoxia; PRP19 silencing increases caspase activity and cell death, and this is rescued by co-silencing PHD3. |
Co-IP of PHD3 with PRP19, domain deletion mapping, siRNA knockdown and overexpression, caspase activity assay, cell death assay |
Experimental cell research |
Medium |
20599946
|
| 2005 |
An alternatively spliced PHD3 transcript (PHD3Δ4) retains prolyl hydroxylase activity as demonstrated in transfection experiments; a second variant (PHD3Δ1) is also expressed ubiquitously, while PHD3Δ4 expression appears restricted to primary cancer tissues. |
RT-PCR identification of splice variants, transfection-based functional hydroxylase activity assay |
Cancer letters |
Low |
16473674
|