| 1997 |
PRK2/PKN2 is a Rho- and Rac-associated serine/threonine kinase (p140); unlike other Rho-binding kinases it associates with both RhoA and Rac1. Interaction with Rho is nucleotide-independent, whereas interaction with Rac is GTP-dependent. Association with either GTPase stimulates PRK2 kinase activity. Expression of kinase-deficient PRK2 in microinjected fibroblasts disrupts actin stress fibers, establishing PRK2 as a downstream effector of Rho/Rac that regulates actin cytoskeletal organization. |
Biochemical purification of p140 from tissues, peptide microsequencing, in vitro binding/nucleotide-dependence assays, in vitro kinase assays with activated GTPases, dominant-negative microinjection into fibroblasts with actin staining |
Molecular and cellular biology |
High |
9121475
|
| 1996 |
PRK2 specifically binds to the middle SH3 domain of the NCK adapter protein and interacts with Rho in a GTP-dependent manner. PRK2 cooperates with Rho family proteins to activate serum response factor (SRF)-dependent transcription, suggesting it bridges receptor tyrosine kinase signals (via NCK) with Rho-dependent transcriptional outputs. |
Bacterial expression library screen with NCK SH3 domains, in vitro GST pulldown, GTP-dependence binding assays, SRF luciferase reporter assays, mouse chromosome mapping by interspecific backcross |
The Journal of biological chemistry |
Medium |
8910519
|
| 1997 |
Rat PRK2 (isolated as PAK-2/PRK2 from liver) is a 130-kDa cytosolic serine/threonine kinase activated by acidic phospholipids (especially cardiolipin) and unsaturated fatty acids. Its catalytic properties — substrate preferences, sensitivity to PKC pseudosubstrate inhibitors — are distinct from but overlapping with PKN/PRK1. |
Protein purification to homogeneity, tryptic peptide sequencing, RT-PCR cDNA analysis, in vitro kinase assays with lipid activators and peptide substrates |
The Journal of biological chemistry |
Medium |
9092545
|
| 1999 |
The C-terminal PDK1-interacting fragment (PIF) of PRK2 docks to PDK1 via a conserved hydrophobic motif; this interaction converts PDK1 from an enzyme that phosphorylates only PKBα Thr308 to one that also phosphorylates Ser473 in a PtdIns(3,4,5)P3-dependent manner, and activates PDK1 ~3-fold by PtdIns(3,4,5)P3. Mutation of conserved PIF residues abolishes the interaction. PRK2 is identified as a probable PDK1 substrate. |
In vitro kinase assays, PDK1–PIF peptide binding assays, mutagenesis of PIF motif, partial purification of brain PDK2 activity and immunoprecipitation with PDK1 antibodies |
Current biology : CB |
High |
10226025
|
| 1998 |
PRK2 is expressed as the predominant PKC-like maternal transcript in starfish oocytes, localizes to the cytoplasm in immature oocytes, and redistributes partially to the disintegrating germinal vesicle during meiotic maturation. PRK2 is phosphorylated in vivo in response to 1-methyladenine stimulus, preceding MPF activation, placing it as an early regulator during meiotic re-entry. |
RT-PCR cloning, subcellular fractionation/immunolocalization, in vivo 32P-labeling after 1-methyladenine stimulation |
Developmental biology |
Medium |
9466886
|
| 2000 |
During TNF-induced apoptosis, caspase cleavage of PRK2 generates a C-terminal fragment (aa 862–908) that specifically binds Akt (identified by yeast two-hybrid and confirmed in mammalian cells) and inhibits Akt kinase activity by blocking phosphorylation at Thr308 and Ser473, leading to inhibition of downstream Akt signaling including BAD phosphorylation and anti-apoptotic activity. |
Yeast two-hybrid screen, co-immunoprecipitation in mammalian cells, in vitro and in vivo kinase assays, apoptosis assays |
The Journal of biological chemistry |
Medium |
10926925
|
| 2001 |
PRK2 interacts with the PDZ3 domain of the protein tyrosine phosphatase PTP-BL via the extreme C-terminal cysteine of PRK2 (a novel PDZ-binding motif). This interaction was demonstrated by yeast two-hybrid and co-immunoprecipitation from transfected HeLa cells, with co-localization of both proteins in lamellipodia-like structures. |
Yeast two-hybrid, co-immunoprecipitation from transfected HeLa cells, site-directed mutagenesis of C-terminal cysteine, immunofluorescence co-localization |
FEBS letters |
Medium |
11356191
|
| 2002 |
Rho–PRK2 signaling promotes keratinocyte cell-cell adhesion via activation of the Fyn tyrosine kinase. An activated Rho mutant defective in PRK2/PKN binding fails to induce cell-cell adhesion. Increased endogenous PRK2 kinase activity during keratinocyte differentiation is sufficient to promote cell-cell adhesion, induce tyrosine phosphorylation of β- and γ-catenin and p120ctn, and activate Fyn, placing PRK2 as a Rho effector upstream of Fyn in this pathway. |
Dominant-negative and constitutively active Rho mutants, Rho mutants with defective PRK2 binding, PRK2 overexpression, kinase activity assays, co-immunoprecipitation, tyrosine phosphorylation assays |
The Journal of cell biology |
High |
11777936
|
| 2002 |
A caspase-3-generated C-terminal PRK2 fragment inhibits PDK1 autophosphorylation by >90% and blocks PDK1-mediated phosphorylation of PKC-ζ and PKC-δ in vitro and in vivo. The C-terminal tail of PKC is required for PKC-ζ/δ phosphorylation by PDK1. This establishes that the apoptotic PRK2 cleavage product acts as a potent negative regulator of PDK1. |
Yeast two-hybrid PDK1 bait screen, co-precipitation from mammalian cells, in vitro PDK1 kinase assays, in vivo phosphorylation assays with PRK2 fragment expression |
Biochemistry |
Medium |
11781095
|
| 2007 |
PRK2 is required for entry into mitosis and exit from cytokinesis in HeLa cells. Specifically, PRK2 is required for abscission at the midbody at the end of cell division, and for phosphorylation and activation of Cdc25B, the phosphatase that activates mitotic cyclin/Cdk1 at the G2/M transition. This links Rho GTPase signaling through PRK2 to cell cycle control. |
siRNA depletion of PRK2 in HeLa S3 cells, live-cell imaging, immunofluorescence for mitotic markers, Cdc25B phosphorylation assays |
The EMBO journal |
High |
17332740
|
| 2008 |
The extreme C-terminal segment of PRK2 is critical for full activation by RhoA in cells in a GTP-dependent manner, although it is dispensable for in vitro activation by RhoA. Two conserved threonines in the activation loop and turn motif are essential for catalytic activity; the phosphomimetic Asp-978 at the hydrophobic motif is dispensable. The PRK2-Δ958 mutant (turn motif truncated) still interacts with PDK1, indicating the hydrophobic and turn motifs are dispensable for PDK1 docking. |
Structure-function mutagenesis, in vitro kinase assays, in vivo RhoA activation assays, PDK1 co-immunoprecipitation |
Archives of biochemistry and biophysics |
Medium |
18835241
|
| 2008 |
Both ROCK and PRK2 kinases promote polyglutamine (huntingtin and androgen receptor) aggregation in cultured cells. Overexpression of either increases aggregation; RNAi knockdown of either reduces aggregation; and the inhibitory effect of Y-27632 on aggregation requires both kinases (epistasis by RNAi). |
Overexpression and RNAi knockdown in cell-based aggregation assays with ROCK-specific inhibitors |
FEBS letters |
Medium |
18423405
|
| 2009 |
PDK1 phosphorylates the activation loop of PRK2. In-vivo 32P labeling identified two PRK2 phosphorylation sites: the activation loop and the zipper/turn-motif (Z/TM) in the C-terminal extension. Phosphorylation of the Z/TM site negatively regulates PRK2 docking to PDK1, providing a self-limiting regulatory mechanism where PRK2 activation inhibits further PDK1 interaction. |
In vivo 32P labeling of recombinant PRK2, phosphopeptide mapping/mass spectrometry, PDK1 docking interaction assays with phospho-site mutants |
The Journal of biological chemistry |
High |
19723632
|
| 2010 |
The Yersinia effector YopM interacts with PRK2 via an internal leucine-rich repeat region (LRR6–LRR15). Both the PRK2-binding domain and the RSK1-binding domain of YopM are required for IL-10 induction in vivo and for virulence, establishing that PRK2 is co-opted by a bacterial effector as part of a signaling complex that suppresses host immunity. |
In vitro binding assays with truncated YopM proteins, murine infection models, serum cytokine measurements, orogastric infection virulence assays |
Infection and immunity |
Medium |
20515922
|
| 2010 |
PRK2 is required for maturation of primordial junctions into apical junctions in human bronchial epithelial cells. PRK2 is recruited to nascent cell-cell contacts via its C2-like domain; Rho binding facilitates this recruitment and is essential for PRK2 function. Kinase-dead PRK2 acts as a dominant-negative, and RhoA binding-deficient PRK2 fails to rescue junction formation, establishing that Rho-activated PRK2 kinase activity is required downstream of Rho for apical junction maturation. |
siRNA library screen targeting 28 Rho effectors, PRK2 depletion by siRNA, domain-mapping with C2-like and Rho-binding mutants, kinase-dead dominant-negative, immunofluorescence localization |
Molecular and cellular biology |
High |
20974804
|
| 2012 |
PRK2 regulation is mediated in trans by an intermolecular PRK2–PRK2 dimerization through its N-terminal region, which prevents interaction with upstream kinase PDK1. Amino acids 487–501 in the linker between N-terminal domains and the catalytic domain contribute to dimer formation. The C-terminal region intramolecularly activates PRK2, and the catalytic domain mediates cross-talk between inhibitory N-terminal and activating C-terminal regions. |
In vitro kinase assays with N-terminal and C-terminal domain constructs, PDK1 interaction assays, mutagenesis of linker region |
The Journal of biological chemistry |
Medium |
22511787
|
| 2012 |
PRK2 phosphorylates the HCV NS5B RNA-dependent RNA polymerase, and this phosphorylation is required for HCV replication. Hsp90 inhibition destabilizes PDK1 (via proteasomal degradation), reducing active PRK2 levels and thereby decreasing NS5B phosphorylation and HCV genome replication. |
Pharmacological Hsp90 inhibition (17-DMAG), Western blotting of phospho-NS5B, HCV replicon replication assays in Huh7 cells, HCV-infected cell assays |
Biochemical and biophysical research communications |
Medium |
22490666
|
| 2013 |
PRK2 HR1a and HR1b domains bind RhoA, RhoB, and RhoC with distinct affinities; RhoB binds more tightly than RhoA or RhoC to PRK isoforms. The PRK1 HR1ab didomain shows similar affinities for RhoA and RhoC as HR1a alone, but RhoB additionally recruits the HR1b domain. PRK2 HR1 domains bind all Rho isoforms less well than PRK1 domains. The PRK2 HR1a domain has the highest thermal stability among PRK HR1 domains. |
Quantitative binding affinity measurements (biophysical assays), thermal stability analysis, domain-specific HR1a and HR1ab constructs |
Biochemistry |
Medium |
24128008
|
| 2015 |
H. pylori CagA toxin interacts directly with PRK2 and inhibits its kinase activity. This interaction disrupts PRK2-dependent cytoskeletal rearrangements and cell polarity pathways in host epithelial cells. |
Co-immunoprecipitation, in vitro kinase activity assay with CagA |
Cellular microbiology |
Medium |
26041307
|
| 2016 |
Constitutive PKN2 knockout in mice results in embryonic lethality at E10 with cardiovascular and morphogenetic defects. The lethal phenotype is not recapitulated by endothelial- or cardiac-specific deletion but is reproduced by inducible systemic deletion after E7, causing collapse of the embryonic mesoderm. Mouse embryonic fibroblasts from PKN2-null embryos are defective in proliferation and motility, and neural crest migration is impaired in vivo, establishing PKN2 as a non-redundant, cell-autonomous regulator of mesoderm expansion and mesodermal-cell function. |
Constitutive and conditional PKN2 knockout mice, inducible systemic deletion (tamoxifen-inducible), tissue-specific Cre deletions, MEF proliferation/motility assays, in vivo neural crest migration analysis |
Cell reports |
High |
26774483
|
| 2016 |
PKN2 forms a complex with Cdo, APPL1, and AKT via its C-terminal region during myoblast differentiation, and this interaction promotes AKT activation and myoblast differentiation. PKN2 overexpression enhances C2C12 differentiation; PKN2 depletion impairs it. PKN2 also mediates recruitment of BAF60c and MyoD to the myogenin promoter, promoting MyoD-responsive transcription. |
Co-immunoprecipitation, shRNA knockdown, overexpression in C2C12 myoblasts, MyoD-responsive luciferase reporter assay, ChIP for BAF60c and MyoD at myogenin promoter, differentiation marker assays |
Cell death & disease |
Medium |
27763641
|
| 2017 |
PKN2 knockout MEFs fail to proliferate, and Cre-mediated ablation of PKN2 in floxed MEFs causes impaired cell proliferation with a decrease in S-phase population by cell cycle analysis. PKN2 knockout mouse embryos fail to undergo axial turning and show insufficient neural tube closure, confirming non-redundant in vivo functions distinct from PKN1 and PKN3. |
Constitutive PKN2 knockout mice, Cre-mediated conditional deletion in MEFs, cell cycle analysis (flow cytometry), proliferation assays |
Genes to cells |
High |
28102564
|
| 2018 |
PKN2 in colon cancer cells directly associates with and phosphorylates/activates DUSP6, a dual-specificity phosphatase that dephosphorylates/inactivates ERK1/2. This suppresses ERK1/2 phosphorylation, reducing CREB/Elk-1 binding to IL-4 and IL-10 promoters, thereby inhibiting M2 macrophage polarization. |
Co-immunoprecipitation (Co-IP) of PKN2 and DUSP6, kinase activity assay for PKN2 on DUSP6, ChIP-qPCR for CREB/Elk-1, luciferase promoter assays, PKN2 siRNA, xenograft models |
Molecular cancer |
Medium |
29368606
|
| 2020 |
Muscle-specific genetic ablation of PAK2/PKN2 (note: this paper uses 'PAK2' to refer to the p21-activated kinase PAK2, NOT PKN2/PRK2; the gene symbol collision must be assessed). Assessment: The paper describes PAK2 (group I PAK family, activated by Rac/Cdc42) in insulin-stimulated glucose uptake in skeletal muscle — this is PAK2 (gene: PAK2), NOT PKN2/PRK2. EXCLUDED as alias collision. |
N/A |
The Journal of physiology |
Low |
32844438
|
| 2020 |
PKN2 localizes to the transition zone of primary cilia upon serum withdrawal (where activating pPRK2 signal is detected), and co-depletion of PRK1 and PRK2 results in reduced cilia length, impaired planar polarity, and impaired cilia-associated signaling. PRK2 depletion also reduces spheroid growth. |
Immunofluorescence localization of phospho-PRK1/2, siRNA co-depletion, cilia length measurement, planar polarity assays, spheroid growth assays, proteomic identification of PRK2 binding partners |
Scientific reports |
Medium |
32127582
|
| 2021 |
PKN2 depletion in fibroblasts reduces cell motility velocity and delays recovery of N-cadherin expression (both protein and mRNA) after trypsin dissociation, impairing cell aggregate compaction and spheroid formation in suspension culture. This establishes PKN2 as a regulator of N-cadherin transcription and cell motility required for spheroid formation. |
Cre-mediated PKN2 deletion in floxed fibroblasts, time-lapse microscopy, immunoblot for N-cadherin, RT-qPCR for N-cadherin mRNA, spheroid formation assays in low-attachment plates |
Biochemistry and biophysics reports |
Medium |
33437883
|
| 2022 |
PKN2 promotes cardiac hypertrophy downstream of angiotensin II: cardiomyocyte-specific PKN2 knockout causes developmental myocardial defects (clefts, ventricular septal defects) and PKN2 haploinsufficiency in adults attenuates angiotensin II-induced cardiac hypertrophy, cardiomyocyte hypertrophy, and fibrosis. |
Cardiomyocyte-specific conditional PKN2 knockout, global PKN2 haploinsufficiency, angiotensin II infusion model, high-resolution episcopic microscopy, MRI, micro-CT, echocardiography, histology, RNAseq |
The Biochemical journal |
High |
35730579
|
| 2024 |
PKN2 allosteric regulation involves a PIF-pocket that communicates with both the ATP-binding site and the pseudosubstrate PKL-binding site. A small compound binding to the PIF-pocket can act as either an allosteric activator (displacing the PKL pseudosubstrate from the active site) or an allosteric inhibitor of PRK2 catalytic activity. PIFtide peptide binding to the PIF-pocket similarly activates PRK2 allosterically. At least two distinct complexes between PRK2 and PDK1 were identified. |
Chemical biology with small compound PIF-pocket ligands, in vitro kinase assays, allosteric activation/inhibition assays, binding interaction studies with PDK1 |
The Journal of biological chemistry |
Medium |
39002682
|
| 2025 |
PKN2 promotes mesenchymal-like cancer cell growth through a PKN2–SAV1–TAZ signaling mechanism, identifying PKN2 as a core regulator of the Hippo tumor suppressor pathway. Biochemical experiments demonstrated the PKN2-SAV1-TAZ interaction, and genetic PKN2 inhibition suppresses drug-tolerant persister cells driven by the mesenchymal-like state. |
Genome-wide essentiality analysis (~800 cancer cell lines), co-essentiality mapping, biochemical interaction experiments (Co-IP/pulldown), genomic analysis of patient tumors, genetic PKN2 inhibition combined with targeted therapies |
Cancer discovery |
Medium |
39560431
|
| 2025 |
PKN2 directly interacts with HIF-1α protein, phosphorylates it, and induces ubiquitination-dependent degradation of HIF-1α, thereby suppressing HIF-1α nuclear accumulation and transcription of VEGFA and bFGF. This inhibits tumor angiogenesis in colon cancer. |
Co-immunoprecipitation of PKN2 and HIF-1α, in vitro phosphorylation assay, ubiquitination assay, HIF-1α nuclear localization by fractionation/immunofluorescence, VEGFA/bFGF promoter assays, in vitro and in vivo tumor angiogenesis models |
The Kaohsiung journal of medical sciences |
Medium |
40515512
|
| 2025 |
PKN2 promotes immunosuppressive activity of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) in esophageal cancer by upregulating STAT3 phosphorylation, which drives CPT1B transcription and fatty acid oxidation (FAO) in PMN-MDSCs. |
PKN2 overexpression in PMN-MDSCs, co-culture with T cells and organoids, Western blotting for phospho-STAT3 and CPT1B, FAO measurement assays |
Molecular medicine |
Medium |
40069590
|
| 2025 |
Upon wound healing, PKN2 relocalizes from cytoplasm to lateral cell-cell junctions in MCF10A epithelial monolayers, where it stabilizes adherens junctions and maintains coordinated collective migration. PKN2 CRISPR KO reduces collective migration due to destabilization of adherens junctions. |
CRISPR/Cas9 PKN2 knockout, wound healing assay, live-cell imaging, immunofluorescence for junction markers, PKN2 relocalization imaging |
Advanced science |
Medium |
41276909
|
| 2026 |
The E3 ubiquitin ligase TRIM40 binds PKN2 via its B-box domain and promotes K63-linked ubiquitination of PKN2 in an E3 ligase activity-dependent manner, enhancing PKN2 phosphorylation at Ser815 and activating downstream pro-hypertrophic signaling. Pharmacological inhibition of PKN2 attenuates cardiac remodeling induced by TRIM40 overexpression. |
TRIM40 knockout and overexpressing mice, angiotensin II/TAC hypertrophy models, Co-IP to map TRIM40-PKN2 interaction, ubiquitination assays (K63-linkage), phospho-PKN2 Ser815 Western blot, PKN2 inhibitor rescue |
Advanced science |
Medium |
41572508
|
| 2026 |
Cardiomyocyte-specific PKN2 knockout causes a ventricular geometry defect traceable to a critical developmental window (E7.5–E10.5). Tamoxifen-induced deletion at E7.5 reproduces the 'coin-pouch' ventricular geometry; deletion at E10.5 spares morphology. Integrative omics at E10.5 reveals transcriptional and proteomic induction of actin cytoskeleton/motility programs with repression of mitotic modules, alongside reduced cardiomyocyte proliferation at E10.5–E11.5. |
Constitutive and inducible cardiomyocyte-specific PKN2 CRE knockout, light-sheet microscopy-based morphometrics, RNA-seq, proteomics, phosphoproteomics, cardiomyocyte proliferation assays (EdU/BrdU) |
Communications biology |
High |
42143091
|