1
|
Kazanietz MG, Cooke M. Protein kinase C signaling "in" and "to" the nucleus: Master kinases in transcriptional regulation. J Biol Chem 2024; 300:105692. [PMID: 38301892 PMCID: PMC10907189 DOI: 10.1016/j.jbc.2024.105692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 01/08/2024] [Accepted: 01/09/2024] [Indexed: 02/03/2024] Open
Abstract
PKC is a multifunctional family of Ser-Thr kinases widely implicated in the regulation of fundamental cellular functions, including proliferation, polarity, motility, and differentiation. Notwithstanding their primary cytoplasmic localization and stringent activation by cell surface receptors, PKC isozymes impel prominent nuclear signaling ultimately impacting gene expression. While transcriptional regulation may be wielded by nuclear PKCs, it most often relies on cytoplasmic phosphorylation events that result in nuclear shuttling of PKC downstream effectors, including transcription factors. As expected from the unique coupling of PKC isozymes to signaling effector pathways, glaring disparities in gene activation/repression are observed upon targeting individual PKC family members. Notably, specific PKCs control the expression and activation of transcription factors implicated in cell cycle/mitogenesis, epithelial-to-mesenchymal transition and immune function. Additionally, PKCs isozymes tightly regulate transcription factors involved in stepwise differentiation of pluripotent stem cells toward specific epithelial, mesenchymal, and hematopoietic cell lineages. Aberrant PKC expression and/or activation in pathological conditions, such as in cancer, leads to profound alterations in gene expression, leading to an extensive rewiring of transcriptional networks associated with mitogenesis, invasiveness, stemness, and tumor microenvironment dysregulation. In this review, we outline the current understanding of PKC signaling "in" and "to" the nucleus, with significant focus on established paradigms of PKC-mediated transcriptional control. Dissecting these complexities would allow the identification of relevant molecular targets implicated in a wide spectrum of diseases.
Collapse
Affiliation(s)
- Marcelo G Kazanietz
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
| | - Mariana Cooke
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
| |
Collapse
|
2
|
Riemann A, Rauschner M, Reime S, Thews O. The Role of microRNAs in Gene Expression and Signaling Response of Tumor Cells to an Acidic Environment. Int J Mol Sci 2023; 24:16919. [PMID: 38069241 PMCID: PMC10707721 DOI: 10.3390/ijms242316919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 11/23/2023] [Accepted: 11/27/2023] [Indexed: 12/18/2023] Open
Abstract
Many tumors are characterized by marked extracellular acidosis due to increased glycolytic metabolism, which affects gene expression and thereby tumor biological behavior. At the same time, acidosis leads to altered expression of several microRNAs (Mir7, Mir183, Mir203, Mir215). The aim of this study was to analyze whether the acidosis-induced changes in cytokines and tumor-related genes are mediated via pH-sensitive microRNAs. Therefore, the expression of Il6, Nos2, Ccl2, Spp1, Tnf, Acat2, Aox1, Crem, Gls2, Per3, Pink1, Txnip, and Ypel3 was examined in acidosis upon simultaneous transfection with microRNA mimics or antagomirs in two tumor lines in vitro and in vivo. In addition, it was investigated whether microRNA expression in acidosis is affected via known pH-sensitive signaling pathways (MAPK, PKC, PI3K), via ROS, or via altered intracellular Ca2+ concentration. pH-dependent microRNAs were shown to play only a minor role in modulating gene expression. Individual genes (e.g., Ccl2, Txnip, Ypel3) appear to be affected by Mir183, Mir203, or Mir215 in acidosis, but these effects are cell line-specific. When examining whether acid-dependent signaling affects microRNA expression, it was found that Mir203 was modulated by MAPK and ROS, Mir7 was affected by PKC, and Mir215 was dependent on the intracellular Ca2+ concentration. Mir183 could be increased by ROS scavenging. These correlations could possibly result in new therapeutic approaches for acidotic tumors.
Collapse
Affiliation(s)
| | | | | | - Oliver Thews
- Julius Bernstein Institute of Physiology, University of Halle-Wittenberg, 06108 Halle, Germany
| |
Collapse
|
3
|
Saiz-Baggetto S, Dolz-Edo L, Méndez E, García-Bolufer P, Marí M, Bañó MC, Fariñas I, Morante-Redolat JM, Igual JC, Quilis I. A Multimodel Study of the Role of Novel PKC Isoforms in the DNA Integrity Checkpoint. Int J Mol Sci 2023; 24:15796. [PMID: 37958781 PMCID: PMC10650207 DOI: 10.3390/ijms242115796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 10/22/2023] [Accepted: 10/29/2023] [Indexed: 11/15/2023] Open
Abstract
The protein kinase C (PKC) family plays important regulatory roles in numerous cellular processes. Saccharomyces cerevisiae contains a single PKC, Pkc1, whereas in mammals, the PKC family comprises nine isoforms. Both Pkc1 and the novel isoform PKCδ are involved in the control of DNA integrity checkpoint activation, demonstrating that this mechanism is conserved from yeast to mammals. To explore the function of PKCδ in a non-tumor cell line, we employed CRISPR-Cas9 technology to obtain PKCδ knocked-out mouse embryonic stem cells (mESCs). This model demonstrated that the absence of PKCδ reduced the activation of the effector kinase CHK1, although it suggested that other isoform(s) might contribute to this function. Therefore, we used yeast to study the ability of each single PKC isoform to activate the DNA integrity checkpoint. Our analysis identified that PKCθ, the closest isoform to PKCδ, was also able to perform this function, although with less efficiency. Then, by generating truncated and mutant versions in key residues, we uncovered differences between the activation mechanisms of PKCδ and PKCθ and identified their essential domains. Our work strongly supports the role of PKC as a key player in the DNA integrity checkpoint pathway and highlights the advantages of combining distinct research models.
Collapse
Affiliation(s)
- Sara Saiz-Baggetto
- Departament de Bioquímica i Biologia Molecular, Universitat de València, 46100 Burjassot, Spain; (S.S.-B.); (L.D.-E.); (M.C.B.)
- Institut de Biotecnologia i Biomedicina (BIOTECMED), Universitat de València, 46100 Burjassot, Spain (I.F.); (J.M.M.-R.)
| | - Laura Dolz-Edo
- Departament de Bioquímica i Biologia Molecular, Universitat de València, 46100 Burjassot, Spain; (S.S.-B.); (L.D.-E.); (M.C.B.)
- Institut de Biotecnologia i Biomedicina (BIOTECMED), Universitat de València, 46100 Burjassot, Spain (I.F.); (J.M.M.-R.)
- Departament de Biologia Cellular, Biologia Funcional i Antropologia Física, Universitat de València, 46100 Burjassot, Spain
| | - Ester Méndez
- Departament de Bioquímica i Biologia Molecular, Universitat de València, 46100 Burjassot, Spain; (S.S.-B.); (L.D.-E.); (M.C.B.)
- Institut de Biotecnologia i Biomedicina (BIOTECMED), Universitat de València, 46100 Burjassot, Spain (I.F.); (J.M.M.-R.)
| | - Pau García-Bolufer
- Institut de Biotecnologia i Biomedicina (BIOTECMED), Universitat de València, 46100 Burjassot, Spain (I.F.); (J.M.M.-R.)
- Departament de Biologia Cellular, Biologia Funcional i Antropologia Física, Universitat de València, 46100 Burjassot, Spain
| | - Miquel Marí
- Institut de Biotecnologia i Biomedicina (BIOTECMED), Universitat de València, 46100 Burjassot, Spain (I.F.); (J.M.M.-R.)
- Departament de Biologia Cellular, Biologia Funcional i Antropologia Física, Universitat de València, 46100 Burjassot, Spain
| | - M. Carmen Bañó
- Departament de Bioquímica i Biologia Molecular, Universitat de València, 46100 Burjassot, Spain; (S.S.-B.); (L.D.-E.); (M.C.B.)
- Institut de Biotecnologia i Biomedicina (BIOTECMED), Universitat de València, 46100 Burjassot, Spain (I.F.); (J.M.M.-R.)
| | - Isabel Fariñas
- Institut de Biotecnologia i Biomedicina (BIOTECMED), Universitat de València, 46100 Burjassot, Spain (I.F.); (J.M.M.-R.)
- Departament de Biologia Cellular, Biologia Funcional i Antropologia Física, Universitat de València, 46100 Burjassot, Spain
| | - José Manuel Morante-Redolat
- Institut de Biotecnologia i Biomedicina (BIOTECMED), Universitat de València, 46100 Burjassot, Spain (I.F.); (J.M.M.-R.)
- Departament de Biologia Cellular, Biologia Funcional i Antropologia Física, Universitat de València, 46100 Burjassot, Spain
| | - J. Carlos Igual
- Departament de Bioquímica i Biologia Molecular, Universitat de València, 46100 Burjassot, Spain; (S.S.-B.); (L.D.-E.); (M.C.B.)
- Institut de Biotecnologia i Biomedicina (BIOTECMED), Universitat de València, 46100 Burjassot, Spain (I.F.); (J.M.M.-R.)
| | - Inma Quilis
- Departament de Bioquímica i Biologia Molecular, Universitat de València, 46100 Burjassot, Spain; (S.S.-B.); (L.D.-E.); (M.C.B.)
- Institut de Biotecnologia i Biomedicina (BIOTECMED), Universitat de València, 46100 Burjassot, Spain (I.F.); (J.M.M.-R.)
| |
Collapse
|
4
|
Aquino A, Bianchi N, Terrazzan A, Franzese O. Protein Kinase C at the Crossroad of Mutations, Cancer, Targeted Therapy and Immune Response. BIOLOGY 2023; 12:1047. [PMID: 37626933 PMCID: PMC10451643 DOI: 10.3390/biology12081047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/18/2023] [Accepted: 07/21/2023] [Indexed: 08/27/2023]
Abstract
The frequent PKC dysregulations observed in many tumors have made these enzymes natural targets for anticancer applications. Nevertheless, this considerable interest in the development of PKC modulators has not led to the expected therapeutic benefits, likely due to the complex biological activities regulated by PKC isoenzymes, often playing ambiguous and protective functions, further driven by the occurrence of mutations. The structure, regulation and functions of PKCs have been extensively covered in other publications. Herein, we focused on PKC alterations mostly associated with complete functional loss. We also addressed the modest yet encouraging results obtained targeting PKC in selected malignancies and the more frequent negative clinical outcomes. The reported observations advocate the need for more selective molecules and a better understanding of the involved pathways. Furthermore, we underlined the most relevant immune mechanisms controlled by PKC isoforms potentially impacting the immune checkpoint inhibitor blockade-mediated immune recovery. We believe that a comprehensive examination of the molecular features of the tumor microenvironment might improve clinical outcomes by tailoring PKC modulation. This approach can be further supported by the identification of potential response biomarkers, which may indicate patients who may benefit from the manipulation of distinctive PKC isoforms.
Collapse
Affiliation(s)
- Angelo Aquino
- Department of Systems Medicine, University of Rome Tor Vergata, 00133 Rome, Italy;
| | - Nicoletta Bianchi
- Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy; (N.B.); (A.T.)
| | - Anna Terrazzan
- Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy; (N.B.); (A.T.)
- Laboratory for Advanced Therapy Technologies (LTTA), University of Ferrara, 44121 Ferrara, Italy
| | - Ornella Franzese
- Department of Systems Medicine, University of Rome Tor Vergata, 00133 Rome, Italy;
| |
Collapse
|
5
|
Anto NP, Muraleedharan A, Nath PR, Sun Z, Keasar C, Livneh E, Braiman A, Altman A, Kong KF, Isakov N. The Peptidyl-Prolyl cis-trans isomerase, Pin1, associates with Protein Kinase C θ via a critical Phospho-Thr-Pro motif in the V3 regulatory domain. Front Immunol 2023; 14:1126464. [PMID: 36969236 PMCID: PMC10031136 DOI: 10.3389/fimmu.2023.1126464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 02/27/2023] [Indexed: 03/11/2023] Open
Abstract
Protein kinase C-θ (PKCθ) is a member of the novel PKC subfamily known for its selective and predominant expression in T lymphocytes where it regulates essential functions required for T cell activation and proliferation. Our previous studies provided a mechanistic explanation for the recruitment of PKCθ to the center of the immunological synapse (IS) by demonstrating that a proline-rich (PR) motif within the V3 region in the regulatory domain of PKCθ is necessary and sufficient for PKCθ IS localization and function. Herein, we highlight the importance of Thr335-Pro residue in the PR motif, the phosphorylation of which is key in the activation of PKCθ and its subsequent IS localization. We demonstrate that the phospho-Thr335-Pro motif serves as a putative binding site for the peptidyl-prolyl cis-trans isomerase (PPIase), Pin1, an enzyme that specifically recognizes peptide bonds at phospho-Ser/Thr-Pro motifs. Binding assays revealed that mutagenesis of PKCθ-Thr335-to-Ala abolished the ability of PKCθ to interact with Pin1, while Thr335 replacement by a Glu phosphomimetic, restored PKCθ binding to Pin1, suggesting that Pin1-PKCθ association is contingent upon the phosphorylation of the PKCθ-Thr335-Pro motif. Similarly, the Pin1 mutant, R17A, failed to associate with PKCθ, suggesting that the integrity of the Pin1 N-terminal WW domain is a requisite for Pin1-PKCθ interaction. In silico docking studies underpinned the role of critical residues in the Pin1-WW domain and the PKCθ phospho-Thr335-Pro motif, to form a stable interaction between Pin1 and PKCθ. Furthermore, TCR crosslinking in human Jurkat T cells and C57BL/6J mouse-derived splenic T cells promoted a rapid and transient formation of Pin1-PKCθ complexes, which followed a T cell activation-dependent temporal kinetic, suggesting a role for Pin1 in PKCθ-dependent early activation events in TCR-triggered T cells. PPIases that belong to other subfamilies, i.e., cyclophilin A or FK506-binding protein, failed to associate with PKCθ, indicating the specificity of the Pin1-PKCθ association. Fluorescent cell staining and imaging analyses demonstrated that TCR/CD3 triggering promotes the colocalization of PKCθ and Pin1 at the cell membrane. Furthermore, interaction of influenza hemagglutinin peptide (HA307-319)-specific T cells with antigen-fed antigen presenting cells (APCs) led to colocalization of PKCθ and Pin1 at the center of the IS. Together, we point to an uncovered function for the Thr335-Pro motif within the PKCθ-V3 regulatory domain to serve as a priming site for its activation upon phosphorylation and highlight its tenability to serve as a regulatory site for the Pin1 cis-trans isomerase.
Collapse
Affiliation(s)
- Nikhil Ponnoor Anto
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Amitha Muraleedharan
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Pulak Ranjan Nath
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Zuoming Sun
- Department of Immunology and Theranostics, Arthur Riggs Diabetes and Metabolism Research Institute, Beckman Research Institute of the City of Hope, Duarte, CA, United States
| | - Chen Keasar
- The Department of Computer Science, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Etta Livneh
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Alex Braiman
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Amnon Altman
- Division of Cell Biology, La Jolla Institute for Immunology, San Diego, CA, United States
| | - Kok-Fai Kong
- Division of Cell Biology, La Jolla Institute for Immunology, San Diego, CA, United States
| | - Noah Isakov
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
- *Correspondence: Noah Isakov,
| |
Collapse
|
6
|
Selective Targeting of Protein Kinase C (PKC)-θ Nuclear Translocation Reduces Mesenchymal Gene Signatures and Reinvigorates Dysfunctional CD8 + T Cells in Immunotherapy-Resistant and Metastatic Cancers. Cancers (Basel) 2022; 14:cancers14061596. [PMID: 35326747 PMCID: PMC8946217 DOI: 10.3390/cancers14061596] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 03/07/2022] [Accepted: 03/14/2022] [Indexed: 02/05/2023] Open
Abstract
Simple Summary Some important signaling proteins that control how cells grow and behave not only act in the cytoplasm but also in the nucleus, where they tether to chromatin. This is especially true for protein kinase C (PKC)-θ, which acts in the nucleus to mediate cancer hallmarks that drive metastasis and in normal T cells. However, current PKC-θ inhibitors are either non-specific or target only its cytoplasmic function. In a bid to develop a novel class of PKC-θ inhibitor that maintains cytoplasmic signaling but inhibits its nuclear function, here we present a novel PKC-θ inhibitor (nPKC-θi2) that specifically inhibits nuclear translocation of PKC-θ without interrupting normal signaling in healthy T cells. We show for the first time that nPKC-θ mediates immunotherapy resistance via its activity in circulating tumor cells and dysfunctional CD8+ T cells. Our novel inhibitor provides a means to target this process by simultaneously overcoming T-cell exhaustion and cancer stem cell burden. As part of a sequential approach with other therapies, this work paves the way for improving outcomes in cancer patients with immunotherapy-resistant relapse and metastasis. Abstract Protein kinase C (PKC)-θ is a serine/threonine kinase with both cytoplasmic and nuclear functions. Nuclear chromatin-associated PKC-θ (nPKC-θ) is increasingly recognized to be pathogenic in cancer, whereas its cytoplasmic signaling is restricted to normal T-cell function. Here we show that nPKC-θ is enriched in circulating tumor cells (CTCs) in patients with triple-negative breast cancer (TNBC) brain metastases and immunotherapy-resistant metastatic melanoma and is associated with poor survival in immunotherapy-resistant disease. To target nPKC-θ, we designed a novel PKC-θ peptide inhibitor (nPKC-θi2) that selectively inhibits nPKC-θ nuclear translocation but not PKC-θ signaling in healthy T cells. Targeting nPKC-θ reduced mesenchymal cancer stem cell signatures in immunotherapy-resistant CTCs and TNBC xenografts. PKC-θ was also enriched in the nuclei of CD8+ T cells isolated from stage IV immunotherapy-resistant metastatic cancer patients. We show for the first time that nPKC-θ complexes with ZEB1, a key repressive transcription factor in epithelial-to-mesenchymal transition (EMT), in immunotherapy-resistant dysfunctional PD1+/CD8+ T cells. nPKC-θi2 inhibited the ZEB1/PKC-θ repressive complex to induce cytokine production in CD8+ T cells isolated from patients with immunotherapy-resistant disease. These data establish for the first time that nPKC-θ mediates immunotherapy resistance via its activity in CTCs and dysfunctional CD8+ T cells. Disrupting nPKC-θ but retaining its cytoplasmic function may offer a means to target metastases in combination with chemotherapy or immunotherapy.
Collapse
|
7
|
He Y, Yang Z, Zhao CS, Xiao Z, Gong Y, Li YY, Chen Y, Du Y, Feng D, Altman A, Li Y. T-cell receptor (TCR) signaling promotes the assembly of RanBP2/RanGAP1-SUMO1/Ubc9 nuclear pore subcomplex via PKC-θ-mediated phosphorylation of RanGAP1. eLife 2021; 10:67123. [PMID: 34110283 PMCID: PMC8225385 DOI: 10.7554/elife.67123] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 06/03/2021] [Indexed: 01/15/2023] Open
Abstract
The nuclear pore complex (NPC) is the sole and selective gateway for nuclear transport, and its dysfunction has been associated with many diseases. The metazoan NPC subcomplex RanBP2, which consists of RanBP2 (Nup358), RanGAP1-SUMO1, and Ubc9, regulates the assembly and function of the NPC. The roles of immune signaling in regulation of NPC remain poorly understood. Here, we show that in human and murine T cells, following T-cell receptor (TCR) stimulation, protein kinase C-θ (PKC-θ) directly phosphorylates RanGAP1 to facilitate RanBP2 subcomplex assembly and nuclear import and, thus, the nuclear translocation of AP-1 transcription factor. Mechanistically, TCR stimulation induces the translocation of activated PKC-θ to the NPC, where it interacts with and phosphorylates RanGAP1 on Ser504 and Ser506. RanGAP1 phosphorylation increases its binding affinity for Ubc9, thereby promoting sumoylation of RanGAP1 and, finally, assembly of the RanBP2 subcomplex. Our findings reveal an unexpected role of PKC-θ as a direct regulator of nuclear import and uncover a phosphorylation-dependent sumoylation of RanGAP1, delineating a novel link between TCR signaling and assembly of the RanBP2 NPC subcomplex.
Collapse
Affiliation(s)
- Yujiao He
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zhiguo Yang
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Chen-Si Zhao
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zhihui Xiao
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yu Gong
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yun-Yi Li
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yiqi Chen
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yunting Du
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Dianying Feng
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Amnon Altman
- Center for Cancer Immunotherapy, La Jolla Institute for Immunology, La Jolla, United States
| | - Yingqiu Li
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| |
Collapse
|
8
|
Tan AHY, Tu W, McCuaig R, Hardy K, Donovan T, Tsimbalyuk S, Forwood JK, Rao S. Lysine-Specific Histone Demethylase 1A Regulates Macrophage Polarization and Checkpoint Molecules in the Tumor Microenvironment of Triple-Negative Breast Cancer. Front Immunol 2019; 10:1351. [PMID: 31249575 PMCID: PMC6582666 DOI: 10.3389/fimmu.2019.01351] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 05/28/2019] [Indexed: 12/14/2022] Open
Abstract
Macrophages play an important role in regulating the tumor microenvironment (TME). Here we show that classical (M1) macrophage polarization reduced expression of LSD1, nuclear REST corepressor 1 (CoREST), and the zinc finger protein SNAIL. The LSD1 inhibitor phenelzine targeted both the flavin adenine dinucleotide (FAD) and CoREST binding domains of LSD1, unlike the LSD1 inhibitor GSK2879552, which only targeted the FAD domain. Phenelzine treatment reduced nuclear demethylase activity and increased transcription and expression of M1-like signatures both in vitro and in a murine triple-negative breast cancer model. Overall, the LSD1 inhibitors phenelzine and GSK2879552 are useful tools for dissecting the contribution of LSD1 demethylase activity and the nuclear LSD1-CoREST complex to switching macrophage polarization programs. These findings suggest that inhibitors must have dual FAD and CoREST targeting abilities to successfully initiate or prime macrophages toward an anti-tumor M1-like phenotype in triple-negative breast cancer.
Collapse
Affiliation(s)
- Abel H Y Tan
- Epigenetics and Transcription Laboratory Melanie Swan Memorial Translational Centre, Sci-Tech, University of Canberra, Canberra, ACT, Australia
| | - WenJuan Tu
- Epigenetics and Transcription Laboratory Melanie Swan Memorial Translational Centre, Sci-Tech, University of Canberra, Canberra, ACT, Australia
| | - Robert McCuaig
- Epigenetics and Transcription Laboratory Melanie Swan Memorial Translational Centre, Sci-Tech, University of Canberra, Canberra, ACT, Australia
| | - Kristine Hardy
- Epigenetics and Transcription Laboratory Melanie Swan Memorial Translational Centre, Sci-Tech, University of Canberra, Canberra, ACT, Australia
| | - Thomasina Donovan
- Epigenetics and Transcription Laboratory Melanie Swan Memorial Translational Centre, Sci-Tech, University of Canberra, Canberra, ACT, Australia
| | - Sofiya Tsimbalyuk
- School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, NSW, Australia
| | - Jade K Forwood
- School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, NSW, Australia
| | - Sudha Rao
- Epigenetics and Transcription Laboratory Melanie Swan Memorial Translational Centre, Sci-Tech, University of Canberra, Canberra, ACT, Australia
| |
Collapse
|
9
|
LSD1 activation promotes inducible EMT programs and modulates the tumour microenvironment in breast cancer. Sci Rep 2018; 8:73. [PMID: 29311580 PMCID: PMC5758711 DOI: 10.1038/s41598-017-17913-x] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 12/04/2017] [Indexed: 12/23/2022] Open
Abstract
Complex regulatory networks control epithelial-to-mesenchymal transition (EMT) but the underlying epigenetic control is poorly understood. Lysine-specific demethylase 1 (LSD1) is a key histone demethylase that alters the epigenetic landscape. Here we explored the role of LSD1 in global epigenetic regulation of EMT, cancer stem cells (CSCs), the tumour microenvironment, and therapeutic resistance in breast cancer. LSD1 induced pan-genomic gene expression in networks implicated in EMT and selectively elicits gene expression programs in CSCs whilst repressing non-CSC programs. LSD1 phosphorylation at serine-111 (LSD1-s111p) by chromatin anchored protein kinase C-theta (PKC-θ), is critical for its demethylase and EMT promoting activity and LSD1-s111p is enriched in chemoresistant cells in vivo. LSD1 couples to PKC-θ on the mesenchymal gene epigenetic template promotes LSD1-mediated gene induction. In vivo, chemotherapy reduced tumour volume, and when combined with an LSD1 inhibitor, abrogated the mesenchymal signature and promoted an innate, M1 macrophage-like tumouricidal immune response. Circulating tumour cells (CTCs) from metastatic breast cancer (MBC) patients were enriched with LSD1 and pharmacological blockade of LSD1 suppressed the mesenchymal and stem-like signature in these patient-derived CTCs. Overall, LSD1 inhibition may serve as a promising epigenetic adjuvant therapy to subvert its pleiotropic roles in breast cancer progression and treatment resistance.
Collapse
|
10
|
Kumar R, Deivendran S, Santhoshkumar TR, Pillai MR. Signaling coupled epigenomic regulation of gene expression. Oncogene 2017. [DOI: 10.1038/onc.2017.201] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
11
|
Ozay EI, Gonzalez-Perez G, Torres JA, Vijayaraghavan J, Lawlor R, Sherman HL, Garrigan DT, Burnside AS, Osborne BA, Tew GN, Minter LM. Intracellular Delivery of Anti-pPKCθ (Thr538) via Protein Transduction Domain Mimics for Immunomodulation. Mol Ther 2016; 24:2118-2130. [PMID: 27633441 DOI: 10.1038/mt.2016.177] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 09/07/2016] [Indexed: 12/12/2022] Open
Abstract
Targeting cellular proteins with antibodies, to better understand cellular signaling pathways in the context of disease modulation, is a fast-growing area of investigation. Humanized antibodies are increasingly gaining attention for their therapeutic potential, but the collection of cellular targets is limited to those secreted from cells or expressed on the cell surface. This approach leaves a wealth of intracellular proteins unexplored as putative targets for antibody binding. Protein kinase Cθ (PKCθ) is essential to T cell activation, proliferation, and differentiation, and its phosphorylation at specific residues is required for its activity. Here we report on the design, synthesis, and characterization of a protein transduction domain mimic capable of efficiently delivering an antibody against phosphorylated PKCθ (Thr538) into human peripheral mononuclear blood cells and altering expression of downstream indicators of T cell activation and differentiation. We used a humanized, lymphocyte transfer model of graft-versus-host disease, to evaluate the durability of protein transduction domain mimic:Anti-pPKCθ modulation, when delivered into human peripheral mononuclear blood cells ex vivo. We demonstrate that protein transduction domain mimic:Antibody complexes can be readily introduced with high efficacy into hard-to-transfect human peripheral mononuclear blood cells, eliciting a biological response sufficient to alter disease progression. Thus, protein transduction domain mimic:Antibody delivery may represent an efficient ex vivo approach to manipulating cellular responses by targeting intracellular proteins.
Collapse
Affiliation(s)
- E Ilker Ozay
- Program in Molecular and Cellular Biology, University of Massachusetts Amherst, Amherst, Massachusetts, USA
| | - Gabriela Gonzalez-Perez
- Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Columbia University, New York, New York, USA
| | - Joe A Torres
- Program in Molecular and Cellular Biology, University of Massachusetts Amherst, Amherst, Massachusetts, USA
| | - Jyothi Vijayaraghavan
- Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, Amherst, Massachusetts, USA
| | - Rebecca Lawlor
- Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, Amherst, Massachusetts, USA
| | - Heather L Sherman
- Program in Molecular and Cellular Biology, University of Massachusetts Amherst, Amherst, Massachusetts, USA
| | - Daniel T Garrigan
- Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, Amherst, Massachusetts, USA
| | - Amy S Burnside
- Institute for Applied Life Sciences, University of Massachusetts Amherst, Amherst, Massachusetts, USA
| | - Barbara A Osborne
- Program in Molecular and Cellular Biology, University of Massachusetts Amherst, Amherst, Massachusetts, USA.,Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, Amherst, Massachusetts, USA
| | - Gregory N Tew
- Program in Molecular and Cellular Biology, University of Massachusetts Amherst, Amherst, Massachusetts, USA.,Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, Amherst, Massachusetts, USA.,Department of Polymer Science and Engineering, University of Massachusetts Amherst, Amherst, Massachusetts, USA
| | - Lisa M Minter
- Program in Molecular and Cellular Biology, University of Massachusetts Amherst, Amherst, Massachusetts, USA.,Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, Amherst, Massachusetts, USA
| |
Collapse
|
12
|
Li J, Hardy K, Phetsouphanh C, Tu WJ, Sutcliffe EL, McCuaig R, Sutton CR, Zafar A, Munier CML, Zaunders JJ, Xu Y, Theodoratos A, Tan A, Lim PS, Knaute T, Masch A, Zerweck J, Brezar V, Milburn PJ, Dunn J, Casarotto MG, Turner SJ, Seddiki N, Kelleher AD, Rao S. Nuclear PKC-θ facilitates rapid transcriptional responses in human memory CD4+ T cells through p65 and H2B phosphorylation. J Cell Sci 2016; 129:2448-61. [PMID: 27149922 PMCID: PMC4920249 DOI: 10.1242/jcs.181248] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 04/21/2016] [Indexed: 12/14/2022] Open
Abstract
Memory T cells are characterized by their rapid transcriptional programs upon re-stimulation. This transcriptional memory response is facilitated by permissive chromatin, but exactly how the permissive epigenetic landscape in memory T cells integrates incoming stimulatory signals remains poorly understood. By genome-wide ChIP-sequencing ex vivo human CD4+ T cells, here, we show that the signaling enzyme, protein kinase C theta (PKC-θ) directly relays stimulatory signals to chromatin by binding to transcriptional-memory-responsive genes to induce transcriptional activation. Flanked by permissive histone modifications, these PKC-enriched regions are significantly enriched with NF-κB motifs in ex vivo bulk and vaccinia-responsive human memory CD4+ T cells. Within the nucleus, PKC-θ catalytic activity maintains the Ser536 phosphorylation on the p65 subunit of NF-κB (also known as RelA) and can directly influence chromatin accessibility at transcriptional memory genes by regulating H2B deposition through Ser32 phosphorylation. Furthermore, using a cytoplasm-restricted PKC-θ mutant, we highlight that chromatin-anchored PKC-θ integrates activating signals at the chromatin template to elicit transcriptional memory responses in human memory T cells. Summary: Memory T cells have a rapid transcriptional program upon re-stimulation. Chromatin-anchored PKC-θ integrates activating signals at the chromatin template to elicit this transcriptional memory in T cells.
Collapse
Affiliation(s)
- Jasmine Li
- Faculty of Education, Science, Technology & Mathematics, University of Canberra, Canberra, Australian Capital Territory 2617, Australia Department of Microbiology & Immunology, The Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Kristine Hardy
- Faculty of Education, Science, Technology & Mathematics, University of Canberra, Canberra, Australian Capital Territory 2617, Australia
| | - Chan Phetsouphanh
- The Kirby Institute, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Wen Juan Tu
- Faculty of Education, Science, Technology & Mathematics, University of Canberra, Canberra, Australian Capital Territory 2617, Australia
| | - Elissa L Sutcliffe
- Faculty of Education, Science, Technology & Mathematics, University of Canberra, Canberra, Australian Capital Territory 2617, Australia
| | - Robert McCuaig
- Faculty of Education, Science, Technology & Mathematics, University of Canberra, Canberra, Australian Capital Territory 2617, Australia
| | - Christopher R Sutton
- Faculty of Education, Science, Technology & Mathematics, University of Canberra, Canberra, Australian Capital Territory 2617, Australia
| | - Anjum Zafar
- Faculty of Education, Science, Technology & Mathematics, University of Canberra, Canberra, Australian Capital Territory 2617, Australia
| | - C Mee Ling Munier
- The Kirby Institute, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - John J Zaunders
- The Kirby Institute, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Yin Xu
- The Kirby Institute, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Angelo Theodoratos
- The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory 0200, Australia
| | - Abel Tan
- Faculty of Education, Science, Technology & Mathematics, University of Canberra, Canberra, Australian Capital Territory 2617, Australia
| | - Pek Siew Lim
- Faculty of Education, Science, Technology & Mathematics, University of Canberra, Canberra, Australian Capital Territory 2617, Australia
| | - Tobias Knaute
- JPT Peptide Technologies Gmbh, Berlin 12489, Germany
| | - Antonia Masch
- Department of Enzymology, Institute of Biochemistry & Biotechnology, Martin-Luther-University Halle-Wittenberg, Halle 06108, Germany
| | | | - Vedran Brezar
- INSERM U955 Eq16 Faculte de medicine Henri Mondor and Universite Paris-Est Creteil/Vaccine Research Institute, Creteil 94010, France
| | - Peter J Milburn
- The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory 0200, Australia
| | - Jenny Dunn
- Faculty of Education, Science, Technology & Mathematics, University of Canberra, Canberra, Australian Capital Territory 2617, Australia
| | - Marco G Casarotto
- The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory 0200, Australia
| | - Stephen J Turner
- Department of Microbiology & Immunology, The Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Nabila Seddiki
- INSERM U955 Eq16 Faculte de medicine Henri Mondor and Universite Paris-Est Creteil/Vaccine Research Institute, Creteil 94010, France
| | - Anthony D Kelleher
- The Kirby Institute, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Sudha Rao
- Faculty of Education, Science, Technology & Mathematics, University of Canberra, Canberra, Australian Capital Territory 2617, Australia
| |
Collapse
|
13
|
McCuaig RD, Dunn J, Li J, Masch A, Knaute T, Schutkowski M, Zerweck J, Rao S. PKC-Theta is a Novel SC35 Splicing Factor Regulator in Response to T Cell Activation. Front Immunol 2015; 6:562. [PMID: 26594212 PMCID: PMC4633479 DOI: 10.3389/fimmu.2015.00562] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 10/21/2015] [Indexed: 11/13/2022] Open
Abstract
Alternative splicing of nuclear pre-mRNA is essential for generating protein diversity and regulating gene expression. While many immunologically relevant genes undergo alternative splicing, the role of regulated splicing in T cell immune responses is largely unexplored, and the signaling pathways and splicing factors that regulate alternative splicing in T cells are poorly defined. Here, we show using a combination of Jurkat T cells, human primary T cells, and ex vivo naïve and effector virus-specific T cells isolated after influenza A virus infection that SC35 phosphorylation is induced in response to stimulatory signals. We show that SC35 colocalizes with RNA polymerase II in activated T cells and spatially overlaps with H3K27ac and H3K4me3, which mark transcriptionally active genes. Interestingly, SC35 remains coupled to the active histone marks in the absence of continuing stimulatory signals. We show for the first time that nuclear PKC-θ co-exists with SC35 in the context of the chromatin template and is a key regulator of SC35 in T cells, directly phosphorylating SC35 peptide residues at RNA recognition motif and RS domains. Collectively, our findings suggest that nuclear PKC-θ is a novel regulator of the key splicing factor SC35 in T cells.
Collapse
Affiliation(s)
- Robert Duncan McCuaig
- Discipline of Biomedical Sciences, Faculty of Education, Science, Technology and Maths, University of Canberra , Canberra, ACT , Australia
| | - Jennifer Dunn
- Discipline of Biomedical Sciences, Faculty of Education, Science, Technology and Maths, University of Canberra , Canberra, ACT , Australia
| | - Jasmine Li
- Department of Microbiology and Immunology, The Doherty Institute for Infection and Immunity, University of Melbourne , Melbourne, VIC , Australia
| | - Antonia Masch
- Department of Enzymology, Institute of Biochemistry and Biotechnology, Martin-Luther-University , Halle , Germany
| | | | - Mike Schutkowski
- Department of Enzymology, Institute of Biochemistry and Biotechnology, Martin-Luther-University , Halle , Germany
| | | | - Sudha Rao
- Discipline of Biomedical Sciences, Faculty of Education, Science, Technology and Maths, University of Canberra , Canberra, ACT , Australia
| |
Collapse
|
14
|
Brezar V, Tu WJ, Seddiki N. PKC-Theta in Regulatory and Effector T-cell Functions. Front Immunol 2015; 6:530. [PMID: 26528291 PMCID: PMC4602307 DOI: 10.3389/fimmu.2015.00530] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 09/28/2015] [Indexed: 01/20/2023] Open
Abstract
One of the major goals in immunology research is to understand the regulatory mechanisms that underpin the rapid switch on/off of robust and efficient effector (Teffs) or regulatory (Tregs) T-cell responses. Understanding the molecular mechanisms underlying the regulation of such responses is critical for the development of effective therapies. T-cell activation involves the engagement of T-cell receptor and co-stimulatory signals, but the subsequent recruitment of serine/threonine-specific protein Kinase C-theta (PKC-θ) to the immunological synapse (IS) is instrumental for the formation of signaling complexes, which ultimately lead to a transcriptional network in T cells. Recent studies demonstrated that major differences between Teffs and Tregs occurred at the IS where its formation induces altered signaling pathways in Tregs. These pathways are characterized by reduced recruitment of PKC-θ, suggesting that PKC-θ inhibits Tregs suppressive function in a negative feedback loop. As the balance of Teffs and Tregs has been shown to be central in several diseases, it was not surprising that some studies revealed that PKC-θ plays a major role in the regulation of this balance. This review will examine recent knowledge on the role of PKC-θ in T-cell transcriptional responses and how this protein can impact on the function of both Tregs and Teffs.
Collapse
Affiliation(s)
- Vedran Brezar
- INSERM U955, Équipe 16 and Faculté de Médecine, Université Paris Est , Créteil , France ; Vaccine Research Institute (VRI) , Créteil , France
| | - Wen Juan Tu
- Faculty of Education, Science, Technology and Maths, University of Canberra , Canberra, ACT , Australia
| | - Nabila Seddiki
- INSERM U955, Équipe 16 and Faculté de Médecine, Université Paris Est , Créteil , France ; Vaccine Research Institute (VRI) , Créteil , France
| |
Collapse
|
15
|
Lim PS, Sutton CR, Rao S. Protein kinase C in the immune system: from signalling to chromatin regulation. Immunology 2015; 146:508-22. [PMID: 26194700 DOI: 10.1111/imm.12510] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 06/29/2015] [Accepted: 07/15/2015] [Indexed: 12/12/2022] Open
Abstract
Protein kinase C (PKC) form a key family of enzymes involved in signalling pathways that specifically phosphorylates substrates at serine/threonine residues. Phosphorylation by PKC is important in regulating a variety of cellular events such as cell proliferation and the regulation of gene expression. In the immune system, PKCs are involved in regulating signal transduction pathways important for both innate and adaptive immunity, ultimately resulting in the expression of key immune genes. PKCs act as mediators during immune cell signalling through the immunological synapse. PKCs are traditionally known to be cytoplasmic signal transducers and are well embedded in the signalling pathways of cells to mediate the cells' response to a stimulus from the plasma membrane to the nucleus. PKCs are also found to transduce signals within the nucleus, a process that is distinct from the cytoplasmic signalling pathway. There is now growing evidence suggesting that PKC can directly regulate gene expression programmes through a non-traditional role as nuclear kinases. In this review, we will focus on the role of PKCs as key cytoplasmic signal transducers in immune cell signalling, as well as its role in nuclear signal transduction. We will also highlight recent evidence for its newly discovered regulatory role in the nucleus as a chromatin-associated kinase.
Collapse
Affiliation(s)
- Pek Siew Lim
- Discipline of Biomedical Sciences, Faculty of Applied Science, University of Canberra, Canberra, ACT, Australia
| | - Christopher Ray Sutton
- Discipline of Biomedical Sciences, Faculty of Applied Science, University of Canberra, Canberra, ACT, Australia
| | - Sudha Rao
- Discipline of Biomedical Sciences, Faculty of Applied Science, University of Canberra, Canberra, ACT, Australia
| |
Collapse
|
16
|
Phetsouphanh C, Kelleher AD. The Role of PKC-θ in CD4+ T Cells and HIV Infection: To the Nucleus and Back Again. Front Immunol 2015; 6:391. [PMID: 26284074 PMCID: PMC4519685 DOI: 10.3389/fimmu.2015.00391] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 07/17/2015] [Indexed: 11/13/2022] Open
Abstract
Protein kinase C (PKC)-θ is the only member of the PKC family that has the ability to translocate to the immunological synapse between T cells and antigen-presenting cells upon T cell receptor and MHC-II recognition. PKC-θ interacts functionally and physically with other downstream effector molecules to mediate T cell activation, differentiation, and migration. It plays a critical role in the generation of Th2 and Th17 responses and is less important in Th1 and CTL responses. PKC-θ has been recently shown to play a role in the nucleus, where it mediates inducible gene expression in the development of memory CD4+ T cells. This novel PKC (nPKC) can up-regulate HIV-1 transcription and PKC-θ activators such as Prostratin have been used in early HIV-1 reservoir eradication studies. The exact manner of the activation of virus by these compounds and the role of PKC-θ, particularly its nuclear form and its association with NF-κB in both the cytoplasmic and nuclear compartments, needs further precise elucidation especially given the very important role of NF-κB in regulating transcription from the integrated retrovirus. Continued studies of this nPKC isoform will give further insight into the complexity of T cell signaling kinases.
Collapse
Affiliation(s)
- Chansavath Phetsouphanh
- The Kirby Institute of Infectious Diseases in Society, University of New South Wales , Sydney, NSW , Australia
| | - Anthony D Kelleher
- The Kirby Institute of Infectious Diseases in Society, University of New South Wales , Sydney, NSW , Australia
| |
Collapse
|
17
|
Chromatinized protein kinase C-θ directly regulates inducible genes in epithelial to mesenchymal transition and breast cancer stem cells. Mol Cell Biol 2014; 34:2961-80. [PMID: 24891615 DOI: 10.1128/mcb.01693-13] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Epithelial to mesenchymal transition (EMT) is activated during cancer invasion and metastasis, enriches for cancer stem cells (CSCs), and contributes to therapeutic resistance and disease recurrence. Signal transduction kinases play a pivotal role as chromatin-anchored proteins in eukaryotes. Here we report for the first time that protein kinase C-theta (PKC-θ) promotes EMT by acting as a critical chromatin-anchored switch for inducible genes via transforming growth factor β (TGF-β) and the key inflammatory regulatory protein NF-κB. Chromatinized PKC-θ exists as an active transcription complex and is required to establish a permissive chromatin state at signature EMT genes. Genome-wide analysis identifies a unique cohort of inducible PKC-θ-sensitive genes that are directly tethered to PKC-θ in the mesenchymal state. Collectively, we show that cross talk between signaling kinases and chromatin is critical for eliciting inducible transcriptional programs that drive mesenchymal differentiation and CSC formation, providing novel mechanisms to target using epigenetic therapy in breast cancer.
Collapse
|
18
|
Isakov N, Altman A. Regulation of immune system cell functions by protein kinase C. Front Immunol 2013; 4:384. [PMID: 24302926 PMCID: PMC3831523 DOI: 10.3389/fimmu.2013.00384] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 11/04/2013] [Indexed: 11/22/2022] Open
Affiliation(s)
- Noah Isakov
- Faculty of Health Sciences, The Shraga Segal Department of Microbiology, Immunology and Genetics, Cancer Research Center, Ben Gurion University of the Negev , Beer Sheva , Israel
| | | |
Collapse
|
19
|
Lim PS, Li J, Holloway AF, Rao S. Epigenetic regulation of inducible gene expression in the immune system. Immunology 2013; 139:285-93. [PMID: 23521628 DOI: 10.1111/imm.12100] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 03/07/2013] [Accepted: 03/13/2013] [Indexed: 01/12/2023] Open
Abstract
T cells are exquisitely poised to respond rapidly to pathogens and have proved an instructive model for exploring the regulation of inducible genes. Individual genes respond to antigenic stimulation in different ways, and it has become clear that the interplay between transcription factors and the chromatin platform of individual genes governs these responses. Our understanding of the complexity of the chromatin platform and the epigenetic mechanisms that contribute to transcriptional control has expanded dramatically in recent years. These mechanisms include the presence/absence of histone modification marks, which form an epigenetic signature to mark active or inactive genes. These signatures are dynamically added or removed by epigenetic enzymes, comprising an array of histone-modifying enzymes, including the more recently recognized chromatin-associated signalling kinases. In addition, chromatin-remodelling complexes physically alter the chromatin structure to regulate chromatin accessibility to transcriptional regulatory factors. The advent of genome-wide technologies has enabled characterization of the chromatin landscape of T cells in terms of histone occupancy, histone modification patterns and transcription factor association with specific genomic regulatory regions, generating a picture of the T-cell epigenome. Here, we discuss the multi-layered regulation of inducible gene expression in the immune system, focusing on the interplay between transcription factors, and the T-cell epigenome, including the role played by chromatin remodellers and epigenetic enzymes. We will also use IL2, a key inducible cytokine gene in T cells, as an example of how the different layers of epigenetic mechanisms regulate immune responsive genes during T-cell activation.
Collapse
Affiliation(s)
- Pek Siew Lim
- Discipline of Biomedical Sciences, Faculty of Education, Science, Technology and Mathematics, University of Canberra, Canberra, Australia.
| | | | | | | |
Collapse
|