TNIK-driven regulation of ERK5 transcriptional activity in endothelial cells
Extracellular signal-regulated kinase 5 (ERK5) is essential for cardiovascular development and endothelial cell (EC) function. Activation of ERK5 through MEK5-mediated phosphorylation at threonine 218 and tyrosine 220 (T218/Y220) drives the transcriptional activation of myocyte enhancer factor-2 (ME...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2025-07-01
|
| Series: | Frontiers in Cardiovascular Medicine |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/fcvm.2025.1526676/full |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849428414043258880 |
|---|---|
| author | Venkata Subrahmanya Kumar Samanthapudi Sivareddy Kotla Nhat-Tu Le |
| author_facet | Venkata Subrahmanya Kumar Samanthapudi Sivareddy Kotla Nhat-Tu Le |
| author_sort | Venkata Subrahmanya Kumar Samanthapudi |
| collection | DOAJ |
| description | Extracellular signal-regulated kinase 5 (ERK5) is essential for cardiovascular development and endothelial cell (EC) function. Activation of ERK5 through MEK5-mediated phosphorylation at threonine 218 and tyrosine 220 (T218/Y220) drives the transcriptional activation of myocyte enhancer factor-2 (MEF2), promoting the expression of KLF2 and KLF4—key transcription factors that maintain vascular homeostasis. We previously demonstrated that ponatinib suppresses ERK5 transcriptional activity without affecting laminar-flow (l-flow)-induced T218/Y220 phosphorylation, suggesting a non-canonical regulatory mechanism. Since ponatinib inhibits Traf2- and Nck-interacting kinase (TNIK), we hypothesized that TNIK modulates ERK5 transcriptional activity. Using a mammalian one-hybrid assay and quantitative RT-PCR (qRT-PCR), we show that TNIK knockdown reduces ERK5 transcriptional activity and downregulates KLF2, KLF4, and eNOS expression, whereas TNIK overexpression enhances ERK5 transcriptional activity. Constitutively active MEK5 (CA-MEK5α) rescues ERK5 transcriptional activity in TNIK-depleted cells, but TNIK overexpression fails to overcome inhibition by dominant-negative MEK5 (DN-MEK5), indicating a MEK5-dependent mechanism. Moreover, phosphorylation-deficient TNIK mutants (S764A and S769A) retain the ability to enhance ERK5 transcriptional activity, suggesting a kinase-independent regulatory role. TNIK knockdown also increases NFκB activity and EC apoptosis, linking TNIK to the regulation of inflammatory and survival pathways. These findings identify TNIK as a novel modulator of ERK5 signaling through both MEK5-dependent and independent mechanisms, highlighting its potential as a therapeutic target for vascular inflammation and endothelial dysfunction. |
| format | Article |
| id | doaj-art-13da0717c5a847f2a982f930a38a0299 |
| institution | Kabale University |
| issn | 2297-055X |
| language | English |
| publishDate | 2025-07-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Cardiovascular Medicine |
| spelling | doaj-art-13da0717c5a847f2a982f930a38a02992025-08-20T03:28:43ZengFrontiers Media S.A.Frontiers in Cardiovascular Medicine2297-055X2025-07-011210.3389/fcvm.2025.15266761526676TNIK-driven regulation of ERK5 transcriptional activity in endothelial cellsVenkata Subrahmanya Kumar Samanthapudi0Sivareddy Kotla1Nhat-Tu Le2Department of Cardiology, The University of Texas MD Anderson Cancer Center, Houston, TX, United StatesDepartment of Cardiology, The University of Texas MD Anderson Cancer Center, Houston, TX, United StatesAcademic Institute, Department of Cardiovascular Sciences, Center for Cardiovascular Sciences, Weill Cornell Medical College, Houston Methodist Research Institute, Houston, TX, United StatesExtracellular signal-regulated kinase 5 (ERK5) is essential for cardiovascular development and endothelial cell (EC) function. Activation of ERK5 through MEK5-mediated phosphorylation at threonine 218 and tyrosine 220 (T218/Y220) drives the transcriptional activation of myocyte enhancer factor-2 (MEF2), promoting the expression of KLF2 and KLF4—key transcription factors that maintain vascular homeostasis. We previously demonstrated that ponatinib suppresses ERK5 transcriptional activity without affecting laminar-flow (l-flow)-induced T218/Y220 phosphorylation, suggesting a non-canonical regulatory mechanism. Since ponatinib inhibits Traf2- and Nck-interacting kinase (TNIK), we hypothesized that TNIK modulates ERK5 transcriptional activity. Using a mammalian one-hybrid assay and quantitative RT-PCR (qRT-PCR), we show that TNIK knockdown reduces ERK5 transcriptional activity and downregulates KLF2, KLF4, and eNOS expression, whereas TNIK overexpression enhances ERK5 transcriptional activity. Constitutively active MEK5 (CA-MEK5α) rescues ERK5 transcriptional activity in TNIK-depleted cells, but TNIK overexpression fails to overcome inhibition by dominant-negative MEK5 (DN-MEK5), indicating a MEK5-dependent mechanism. Moreover, phosphorylation-deficient TNIK mutants (S764A and S769A) retain the ability to enhance ERK5 transcriptional activity, suggesting a kinase-independent regulatory role. TNIK knockdown also increases NFκB activity and EC apoptosis, linking TNIK to the regulation of inflammatory and survival pathways. These findings identify TNIK as a novel modulator of ERK5 signaling through both MEK5-dependent and independent mechanisms, highlighting its potential as a therapeutic target for vascular inflammation and endothelial dysfunction.https://www.frontiersin.org/articles/10.3389/fcvm.2025.1526676/fullERK5TNIKtranscriptional activityinflammationendothelial cells |
| spellingShingle | Venkata Subrahmanya Kumar Samanthapudi Sivareddy Kotla Nhat-Tu Le TNIK-driven regulation of ERK5 transcriptional activity in endothelial cells Frontiers in Cardiovascular Medicine ERK5 TNIK transcriptional activity inflammation endothelial cells |
| title | TNIK-driven regulation of ERK5 transcriptional activity in endothelial cells |
| title_full | TNIK-driven regulation of ERK5 transcriptional activity in endothelial cells |
| title_fullStr | TNIK-driven regulation of ERK5 transcriptional activity in endothelial cells |
| title_full_unstemmed | TNIK-driven regulation of ERK5 transcriptional activity in endothelial cells |
| title_short | TNIK-driven regulation of ERK5 transcriptional activity in endothelial cells |
| title_sort | tnik driven regulation of erk5 transcriptional activity in endothelial cells |
| topic | ERK5 TNIK transcriptional activity inflammation endothelial cells |
| url | https://www.frontiersin.org/articles/10.3389/fcvm.2025.1526676/full |
| work_keys_str_mv | AT venkatasubrahmanyakumarsamanthapudi tnikdrivenregulationoferk5transcriptionalactivityinendothelialcells AT sivareddykotla tnikdrivenregulationoferk5transcriptionalactivityinendothelialcells AT nhattule tnikdrivenregulationoferk5transcriptionalactivityinendothelialcells |