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Sun Y, Li W, Li X, Zheng H, Qiu Y, Yang H. Oncogenic role of karyopherin α2 (KPNA2) in human tumors: A pan-cancer analysis. Comput Biol Med 2021; 139:104955. [PMID: 34735944 DOI: 10.1016/j.compbiomed.2021.104955] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 09/29/2021] [Accepted: 10/15/2021] [Indexed: 12/24/2022]
Abstract
BACKGROUND KPNA2, a nuclear export protein that plays an important role in tumorigenesis, is an emerging hotspot target in oncology. Despite increasing supporting evidence of its importance, no pan-cancer analysis, across multiple databases, is available for in-depth data mining of the gene. METHODS Tumor data from both The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) were explored to investigate the potential oncogenic roles of KPNA2. Diverse analytical methods were used to gain a full-scale understanding of KPNA2: gene expression, survival situations, genetic mutations, DNA methylation, sites of protein phosphorylation, immunocyte infiltration, and correlative cellular pathways. RESULTS KPNA2 is highly expressed in many cancers, and different correlations exist between KPNA2 expression and prognosis of cancer patients. cBioPortal reported that a nonsense mutation of R285* was considered to be the primary tumorigenic genetic alteration to KPNA2 and was found in cases of LUSC, STAD, and CESC. Enhanced phosphorylation of S62 was found in several cancers and the level of infiltration of cancer-associated fibroblasts was found to be linearly correlated with KPNA2 expression levels in ACC, BRCA, MESO, TGCT, THCA, and THYM. Correlations between KPNA2 DNA methylation and the pathogenesis of various tumors in TCGA were further identified. KEGG and GO enrichment analysis identified cell cycle, microtubule binding, and tubulin binding functions for KPNA2. CONCLUSION This is the first pan-cancer analysis focusing on KPNA2. It provides a comprehensive understanding about the role of KPNA2 in tumorigenesis and highlights the potential targeted role of KPNA2 for cancer study.
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Affiliation(s)
- Yiming Sun
- Department of General Surgery, The Affiliated Xinqiao Hospital of Army Medical University, Chongqing, China
| | - Wenjing Li
- Department of the Stem Cell and Regenerative Medicine, The Affiliated Southwest Hospital of Army Medical University, China
| | - Xiaolong Li
- Department of General Surgery, The Affiliated Xinqiao Hospital of Army Medical University, Chongqing, China
| | - Hong Zheng
- Amy Medical University, Chongqing, China
| | - Yuan Qiu
- Department of General Surgery, The Affiliated Xinqiao Hospital of Army Medical University, Chongqing, China.
| | - Hua Yang
- Department of General Surgery, The Affiliated Xinqiao Hospital of Army Medical University, Chongqing, China.
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2
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Liu T, Li Y, Su H, Zhang H, Jones D, Zhou HJ, Ji W, Min W. Nuclear localization of the tyrosine kinase BMX mediates VEGFR2 expression. J Cell Mol Med 2020; 24:126-138. [PMID: 31642192 PMCID: PMC6933376 DOI: 10.1111/jcmm.14663] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 08/15/2019] [Accepted: 08/22/2019] [Indexed: 12/12/2022] Open
Abstract
Vascular endothelial growth factor receptors (VEGFRs) are major contributors to angiogenesis and lymphangiogenesis through the binding of VEGF ligands. We have previously shown that the bone marrow tyrosine kinase BMX is critical for inflammatory angiogenesis via its direct transactivation of VEGFR2. In the present study, we show that siRNA-mediated silencing of BMX led to a significant decrease in the total levels of VEGFR2 mRNA and protein, without affecting their stability, in human endothelial cells (ECs). Interestingly, BMX was detected in the nuclei of ECs, and the SH3 domain of BMX was necessary for its nuclear localization. Luciferase assays showed a significant decrease in the Vegfr2 (kdr) gene promoter activity in ECs after BMX silencing, indicating that BMX is necessary for Vegfr2 transcription. In addition, we found that wild-type BMX, but not a catalytic inactive mutant BMX-K445R, promoted Vegfr2 promoter activity and VEGF-induced EC migration and tube sprouting. Mechanistically, we show that the enhancement of Vegfr2 promoter activity by BMX was mediated by Sp1, a transcription factor critical for the Vegfr2 promoter. Loss of BMX significantly reduced Sp1 binding to the Vegfr2 promoter as assayed by chromatin immunoprecipitation assays. Wild-type BMX, but not a kinase-inactive form of BMX, associated with and potentially phosphorylated Sp1. Moreover, a nuclear-targeted BMX (NLS-BMX), but not cytoplasm-localized form (NES-BMX), bound to Sp1 and augmented VEGFR2 expression. In conclusion, we uncovered a novel function of nuclear-localized BMX in regulating VEGFR2 expression and angiogenesis, suggesting that BMX is a therapeutic target for angiogenesis-related diseases.
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Affiliation(s)
- Tingting Liu
- The Center for Translational MedicineThe First Affiliated HospitalSun Yat‐sen UniversityGuangzhouGuangdongChina
| | - Yonghao Li
- Zhongshan Ophthalmic CenterSun Yat‐sen UniversityGuangzhouGuangdongChina
| | - Hong Su
- The Center for Translational MedicineThe First Affiliated HospitalSun Yat‐sen UniversityGuangzhouGuangdongChina
| | - Haifeng Zhang
- Department of Pathology and the Vascular Biology and Therapeutics ProgramYale University School of MedicineNew HavenCTUSA
| | - Dennis Jones
- Department of Pathology and Laboratory MedicineBoston University School of MedicineBostonMAUSA
| | - Huanjiao Jenny Zhou
- Department of Pathology and the Vascular Biology and Therapeutics ProgramYale University School of MedicineNew HavenCTUSA
| | - Weidong Ji
- The Center for Translational MedicineThe First Affiliated HospitalSun Yat‐sen UniversityGuangzhouGuangdongChina
| | - Wang Min
- Department of Pathology and the Vascular Biology and Therapeutics ProgramYale University School of MedicineNew HavenCTUSA
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3
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Andersen TCB, Kristiansen PE, Huszenicza Z, Johansson MU, Gopalakrishnan RP, Kjelstrup H, Boyken S, Sundvold-Gjerstad V, Granum S, Sørli M, Backe PH, Fulton DB, Karlsson BG, Andreotti AH, Spurkland A. The SH3 domains of the protein kinases ITK and LCK compete for adjacent sites on T cell-specific adapter protein. J Biol Chem 2019; 294:15480-15494. [PMID: 31484725 DOI: 10.1074/jbc.ra119.008318] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 08/22/2019] [Indexed: 12/22/2022] Open
Abstract
T-cell activation requires stimulation of specific intracellular signaling pathways in which protein-tyrosine kinases, phosphatases, and adapter proteins interact to transmit signals from the T-cell receptor to the nucleus. Interactions of LCK proto-oncogene, SRC family tyrosine kinase (LCK), and the IL-2-inducible T cell kinase (ITK) with the T cell-specific adapter protein (TSAD) promotes LCK-mediated phosphorylation and thereby ITK activation. Both ITK and LCK interact with TSAD's proline-rich region (PRR) through their Src homology 3 (SH3) domains. Whereas LCK may also interact with TSAD through its SH2 domain, ITK interacts with TSAD only through its SH3 domain. To begin to understand on a molecular level how the LCK SH3 and ITK SH3 domains interact with TSAD in human HEK293T cells, here we combined biochemical analyses with NMR spectroscopy. We found that the ITK and LCK SH3 domains potentially have adjacent and overlapping binding sites within the TSAD PRR amino acids (aa) 239-274. Pulldown experiments and NMR spectroscopy revealed that both domains may bind to TSAD aa 239-256 and aa 257-274. Co-immunoprecipitation experiments further revealed that both domains may also bind simultaneously to TSAD aa 242-268. Accordingly, NMR spectroscopy indicated that the SH3 domains may compete for these two adjacent binding sites. We propose that once the associations of ITK and LCK with TSAD promote the ITK and LCK interaction, the interactions among TSAD, ITK, and LCK are dynamically altered by ITK phosphorylation status.
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Affiliation(s)
- Thorny Cesilie Bie Andersen
- Institute of Basic Medical Sciences, Department of Molecular Medicine, University of Oslo, 0317 Oslo, Norway
| | | | - Zsuzsa Huszenicza
- Institute of Basic Medical Sciences, Department of Molecular Medicine, University of Oslo, 0317 Oslo, Norway
| | - Maria U Johansson
- Swedish NMR Centre at the University of Gothenburg, Gothenburg 413 90, Sweden
| | | | - Hanna Kjelstrup
- Institute of Basic Medical Sciences, Department of Molecular Medicine, University of Oslo, 0317 Oslo, Norway
| | - Scott Boyken
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011-1079
| | - Vibeke Sundvold-Gjerstad
- Institute of Basic Medical Sciences, Department of Molecular Medicine, University of Oslo, 0317 Oslo, Norway
| | - Stine Granum
- Institute of Basic Medical Sciences, Department of Molecular Medicine, University of Oslo, 0317 Oslo, Norway
| | - Morten Sørli
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, 1432 Ås, Norway
| | - Paul Hoff Backe
- Department of Microbiology, Oslo University Hospital and University of Oslo, 0424 Oslo, Norway.,Department of Medical Biochemistry, Oslo University Hospital and University of Oslo, 0424 Oslo, Norway
| | - D Bruce Fulton
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011-1079
| | - B Göran Karlsson
- Swedish NMR Centre at the University of Gothenburg, Gothenburg 413 90, Sweden
| | - Amy H Andreotti
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011-1079
| | - Anne Spurkland
- Institute of Basic Medical Sciences, Department of Molecular Medicine, University of Oslo, 0317 Oslo, Norway
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4
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Abstract
The human genome encodes seven isoforms of importin α which are grouped into three subfamilies known as α1, α2 and α3. All isoforms share a fundamentally conserved architecture that consists of an N-terminal, autoinhibitory, importin-β-binding (IBB) domain and a C-terminal Arm (Armadillo)-core that associates with nuclear localization signal (NLS) cargoes. Despite striking similarity in amino acid sequence and 3D structure, importin-α isoforms display remarkable substrate specificity in vivo. In the present review, we look at key differences among importin-α isoforms and provide a comprehensive inventory of known viral and cellular cargoes that have been shown to associate preferentially with specific isoforms. We illustrate how the diversification of the adaptor importin α into seven isoforms expands the dynamic range and regulatory control of nucleocytoplasmic transport, offering unexpected opportunities for pharmacological intervention. The emerging view of importin α is that of a key signalling molecule, with isoforms that confer preferential nuclear entry and spatiotemporal specificity on viral and cellular cargoes directly linked to human diseases.
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Maruyama T, Shimizu J, Suzuki N. T-cell protein tyrosine phosphatase (TCPTP) regulates phosphorylation of Txk, a tyrosine kinase of the Tec family. Inflamm Regen 2014. [DOI: 10.2492/inflammregen.34.240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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6
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Christiansen A, Dyrskjøt L. The functional role of the novel biomarker karyopherin α 2 (KPNA2) in cancer. Cancer Lett 2012; 331:18-23. [PMID: 23268335 PMCID: PMC7126488 DOI: 10.1016/j.canlet.2012.12.013] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 12/11/2012] [Accepted: 12/14/2012] [Indexed: 12/23/2022]
Abstract
In recent years, Karyopherin α 2 (KPNA2) has emerged as a potential biomarker in multiple cancer forms. The aberrant high levels observed in cancer tissue have been associated with adverse patient characteristics, prompting the idea that KPNA2 plays a role in carcinogenesis. This notion is supported by studies in cancer cells, where KPNA2 deregulation has been demonstrated to affect malignant transformation. By virtue of its role in nucleocytoplasmic transport, KPNA2 is implicated in the translocation of several cancer-associated proteins. We provide an overview of the clinical studies that have established the biomarker potential of KPNA2 and describe its functional role with an emphasis on established associations with cancer.
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Affiliation(s)
- Anders Christiansen
- Department of Molecular Medicine, Aarhus University Hospital, Aarhus, Denmark
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7
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Regulation of nucleocytoplasmic shuttling of Bruton's tyrosine kinase (Btk) through a novel SH3-dependent interaction with ankyrin repeat domain 54 (ANKRD54). Mol Cell Biol 2012; 32:2440-53. [PMID: 22527282 DOI: 10.1128/mcb.06620-11] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Bruton's tyrosine kinase (Btk), belonging to the Tec family of tyrosine kinases (TFKs), is essential for B-lymphocyte development. Abrogation of Btk signaling causes human X-linked agammaglobulinemia (XLA) and murine X-linked immunodeficiency (Xid). We employed affinity purification of Flag-tagged Btk, combined with tandem mass spectrometry, to capture and identify novel interacting proteins. We here characterize the interaction with ankryin repeat domain 54 protein (ANKRD54), also known as Lyn-interacting ankyrin repeat protein (Liar). While Btk is a nucleocytoplasmic protein, the Liar pool was found to shuttle at a higher rate than Btk. Importantly, our results suggest that Liar mediates nuclear export of both Btk and another TFK, Txk/Rlk. Liar-mediated Btk shuttling was enriched for activation loop, nonphosphorylated Btk and entirely dependent on Btk's SH3 domain. Liar also showed reduced binding to an aspartic acid phosphomimetic SH3 mutant. Three other investigated nucleus-located proteins, Abl, estrogen receptor β (ERβ), and transcription factor T-bet, were all unaffected by Liar. We mapped the interaction site to the C terminus of the Btk SH3 domain. A biotinylated, synthetic Btk peptide, ARDKNGQEGYIPSNYVTEAEDS, was sufficient for this interaction. Liar is the first protein identified that specifically influences the nucleocytoplasmic shuttling of Btk and Txk and belongs to a rare group of known proteins carrying out this activity in a Crm1-dependent manner.
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8
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Boucheron N, Ellmeier W. The Role of Tec Family Kinases in the Regulation of T-helper-cell Differentiation. Int Rev Immunol 2012; 31:133-54. [DOI: 10.3109/08830185.2012.664798] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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9
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Itk: the rheostat of the T cell response. JOURNAL OF SIGNAL TRANSDUCTION 2011; 2011:297868. [PMID: 21747996 PMCID: PMC3116522 DOI: 10.1155/2011/297868] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Accepted: 01/19/2011] [Indexed: 12/28/2022]
Abstract
The nonreceptor tyrosine kinase Itk plays a key role in TCR-initiated signaling that directly and significantly affects the regulation of PLCγ1 and the consequent mobilization of Ca2+. Itk also participates in the regulation of cytoskeletal reorganization as well as cellular adhesion, which is necessary for a productive T cell response. The functional cellular outcome of these molecular regulations by Itk renders it an important mediator of T cell development and differentiation. This paper encompasses the structure of Itk, the signaling parameters leading to Itk activation, and Itk effects on molecular pathways resulting in functional cellular outcomes. The incorporation of these factors persuades one to believe that Itk serves as a modulator, or rheostat, critically fine-tuning the T cell response.
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10
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Abstract
The control of cellular signaling cascades is of utmost importance in regulating the immune response. Exquisitely precise protein-protein interactions and chemical modification of substrates by enzymatic catalysis are the fundamental components of the signals that alert immune cells to the presence of a foreign antigen. In particular, the phosphorylation events induced by protein kinase activity must be spatially and temporally regulated by specific interactions to maintain a normal and effective immune response. High resolution structures of many protein kinases along with supporting biochemical data are providing significant insight into the intricate regulatory mechanisms responsible for controlling cellular signaling. The Tec family kinases are immunologically important kinases for which regulatory details are beginning to emerge. This review focuses on bringing together structural insights gained over the years to develop an understanding of how domain interactions both within the Tec kinases and between the Tec kinases and other signaling molecules control immune cell function.
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Affiliation(s)
- Raji E Joseph
- Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50010, USA
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11
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Gomez-Rodriguez J, Readinger JA, Viorritto IC, Mueller KL, Houghtling RA, Schwartzberg PL. Tec kinases, actin, and cell adhesion. Immunol Rev 2007; 218:45-64. [PMID: 17624943 DOI: 10.1111/j.1600-065x.2007.00534.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The Tec family non-receptor tyrosine kinases have been recognized for their roles in the regulation of phospholipase C-gamma and Ca(2+) mobilization downstream from antigen receptors on lymphocytes. Recent data, however, show that the Tec family kinase interleukin-2-inducible T-cell kinase (Itk) also participates in pathways regulating the actin cytoskeleton and 'inside-out' signaling to integrins downstream from the T-cell antigen receptor. Data suggest that Itk may function in a kinase-independent fashion to regulate proper recruitment of the Vav1 guanine nucleotide exchange factor. By enhancing actin cytoskeleton reorganization, recruitment of signaling molecules to the immune synapse, and integrin clustering in response to both antigen and chemokine receptors, the Tec kinases serve as modulators or amplifiers that can increase the duration of T-cell signaling and regulate T-cell functional responses.
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Affiliation(s)
- Julio Gomez-Rodriguez
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
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12
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Abstract
The Tec family of tyrosine kinases consists of five members (Itk, Rlk, Tec, Btk, and Bmx) that are expressed predominantly in hematopoietic cells. The exceptions, Tec and Bmx, are also found in endothelial cells. Tec kinases constitute the second largest family of cytoplasmic protein tyrosine kinases. While B cells express Btk and Tec, and T cells express Itk, Rlk, and Tec, all four of these kinases (Btk, Itk, Rlk, and Tec) can be detected in mast cells. This chapter will focus on the biochemical and cell biological data that have been accumulated regarding Itk, Rlk, Btk, and Tec. In particular, distinctions between the different Tec kinase family members will be highlighted, with a goal of providing insight into the unique functions of each kinase. The known functions of Tec kinases in T cell and mast cell signaling will then be described, with a particular focus on T cell receptor and mast cell Fc epsilon RI signaling pathways.
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Affiliation(s)
- Martin Felices
- Department of Pathology, University of Massachusetts Medical School, Massachusetts, USA
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13
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Garçon F, Nunès JA. Travel informations on the Tec kinases during lymphocyte activation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2006; 584:15-27. [PMID: 16802596 DOI: 10.1007/0-387-34132-3_2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Affiliation(s)
- Fabien Garçon
- Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Babraham Research Campus, Cambridge CB2 4AT, UK
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14
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Schwartzberg PL, Finkelstein LD, Readinger JA. TEC-family kinases: regulators of T-helper-cell differentiation. Nat Rev Immunol 2005; 5:284-95. [PMID: 15803148 DOI: 10.1038/nri1591] [Citation(s) in RCA: 120] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The TEC-family protein tyrosine kinases ITK, RLK and TEC have been identified as key components of T-cell-receptor signalling that contribute to the regulation of phospholipase C-gamma, the mobilization of Ca(2+) and the activation of mitogen-activated protein kinases. Recent data also show that TEC kinases contribute to T-cell-receptor-driven actin reorganization and cell polarization, which are required for productive T-cell activation. Functional studies have implicated TEC kinases as important mediators of pathways that control the differentiation of CD4(+) T helper cells. Here, we review studies of signalling pathways that involve TEC kinases and how these pathways might contribute to the regulation of T-helper-cell differentiation and function.
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Affiliation(s)
- Pamela L Schwartzberg
- National Human Genome Research Institute, National Institutes of Health, 4A38/49 Convent Drive, Bethesda, Maryland 20892, USA.
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15
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Abstract
The Tec family tyrosine kinases are now recognized as important mediators of antigen receptor signaling in lymphocytes. Three members of this family, Itk, Rlk, and Tec, are expressed in T cells and activated in response to T cell receptor (TCR) engagement. Although initial studies demonstrated a role for these proteins in TCR-mediated activation of phospholipase C-gamma, recent data indicate that Tec family kinases also regulate actin cytoskeletal reorganization and cellular adhesion following TCR stimulation. In addition, Tec family kinases are activated downstream of G protein-coupled chemokine receptors, where they play parallel roles in the regulation of Rho GTPases, cell polarization, adhesion, and migration. In all these systems, however, Tec family kinases are not essential signaling components, but instead function to modulate or amplify signaling pathways. Although they quantitatively reduce proximal signaling, mutations that eliminate Tec family kinases in T cells nonetheless qualitatively alter T cell development and differentiation.
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Affiliation(s)
- Leslie J Berg
- Department of Pathology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA.
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Garçon F, Bismuth G, Isnardon D, Olive D, Nunès JA. Tec Kinase Migrates to the T Cell-APC Interface Independently of Its Pleckstrin Homology Domain. THE JOURNAL OF IMMUNOLOGY 2004; 173:770-5. [PMID: 15240663 DOI: 10.4049/jimmunol.173.2.770] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Tec is the prototypical member of the Tec tyrosine kinases family, which plays an important role in T cell signaling. We show in this study that Tec translocates to the immunological synapse when a T cell contacts a dendritic cell. Surprisingly, the presence of the pleckstrin homology (PH) domain of Tec is not required for this accumulation, and despite a strong activation of 3'-phosphorylated phosphoinositide lipids synthesis during the synapse formation, the Tec PH domain is not redistributed to the T cell plasma membrane. In contrast, we demonstrate that an active Src homology 3 domain is absolutely required, underlining the essential role played by this part of the molecule in the recruitment and/or stabilization of Tec at the immunological synapse. Our results nevertheless suggest that the PH domain controls the kinase activity of the molecule in vivo. We finally demonstrate that the two domains are necessary to trigger transcriptional events following Ag presentation. These data support a model in which the plasma membrane recruitment of the PH-containing protein Tec is not dependent on the production of 3'-phosphorylated phosphoinositide lipids by the PI3K, but rather on an intact Src homology 3 domain.
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Affiliation(s)
- Fabien Garçon
- Institut National de la Santé et de la Recherche Médicale Unité Mixte de Recherche 599, Université de la Méditerranée, Marseille, France
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17
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Schwartzberg PL. Genetic approaches to tyrosine kinase signaling pathways in the immune system. Immunol Res 2004; 27:481-8. [PMID: 12857991 DOI: 10.1385/ir:27:2-3:481] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The development of a productive immune response requires the carefully coordinated activation of lymphocytes through their cell-surface antigen receptors, surface immunoglobulin (Ig) on B cells and the T cell receptor (TCR) on T cells. Studies of mutant cell lines, gene-targeted mice and humans with inherited immunodeficiencies have demonstrated that tyrosine kinases are critical components of lymphocyte antigen-receptor-signaling pathways. Our laboratory is interested in the mechanisms by which modulation of signaling pathways involving tyrosine kinases and related signaling molecules can influence cell function and development. We have concentrated our attention on the genetic and biochemical dissection of signaling pathways in the immune system, and how altering these pathways can change responses to infectious disease. As a model system, we are examining the Tec family kinases and their roles in T lymphocyte development and function.
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Affiliation(s)
- Pamela L Schwartzberg
- Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892-4472, USA.
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18
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Zannini L, Lecis D, Lisanti S, Benetti R, Buscemi G, Schneider C, Delia D. Karyopherin-alpha2 protein interacts with Chk2 and contributes to its nuclear import. J Biol Chem 2003; 278:42346-51. [PMID: 12909615 DOI: 10.1074/jbc.m303304200] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Chk2 is a nuclear protein kinase involved in the DNA damage-induced ataxia telangiectasia mutated-dependent checkpoint arrest at multiple cell cycle phases. Searching for Chk2-binding proteins by a yeast two-hybrid system, we identified a strong interaction with karyopherin-alpha2 (KPNA-2), a gene product involved in active nuclear import of proteins bearing a nuclear localization signal (NLS). This finding was confirmed by glutathione S-transferase pull-down and co-immunoprecipitation assays. Of the three predicted Chk2 NLSs, located at amino acids 179-182 (NLS-1), 240-256 (NLS-2), and 515-522 (NLS-3), only the latter mediated the interaction with KPNA-2 in the yeast two-hybrid system, and in particular with its C terminus. Unlike mutations in NLS-1 or NLS-2, which left the nuclear localization of Chk2 unaffected, mutations in NLS-3 caused a cytoplasmic relocalization, indicating that the NLS-3 motif acts indeed as NLS for Chk2 in vivo. Finally, co-transfection experiments with green fluorescent protein (GFP)-Chk2 and wild type or mutant KPNA-2 confirmed the role of KPNA-2 in nuclear import of Chk2.
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Affiliation(s)
- Laura Zannini
- Department of Experimental Oncology, Istituto Nazionale Tumori, Via G. Venezian 1, 20133 Milan, Italy
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19
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Abstract
The T helper lymphocyte is responsible for orchestrating the appropriate immune response to a wide variety of pathogens. The recognition of the polarized T helper cell subsets Th1 and Th2 has led to an understanding of the role of these cells in coordinating a variety of immune responses, both in responses to pathogens and in autoimmune and allergic disease. Here, we discuss the mechanisms that control lineage commitment to the Th1 phenotype. What has recently emerged is a rich understanding of the cytokines, receptors, signal transduction pathways, and transcription factors involved in Th1 differentiation. Although the picture is still incomplete, the basic pathways leading to Th1 differentiation can now be understood in in vitro and a number of infection and disease models.
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Affiliation(s)
- Susanne J Szabo
- Department of Immunology and Infectious Diseases, Harvard School of Public Health Boston, Massachusetts 02115, USA.
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20
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Takesono A, Finkelstein LD, Schwartzberg PL. Beyond calcium: new signaling pathways for Tec family kinases. J Cell Sci 2002; 115:3039-48. [PMID: 12118060 DOI: 10.1242/jcs.115.15.3039] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The Tec kinases represent the second largest family of mammalian non-receptor tyrosine kinases and are distinguished by the presence of distinct proline-rich regions and pleckstrin homology domains that are required for proper regulation and activation. Best studied in lymphocyte and mast cells, these kinases are critical for the full activation of phospholipase-C γ (PLC-γ) and Ca2+ mobilization downstream of antigen receptors. However, it has become increasingly clear that these kinases are activated downstream of many cell-surface receptors,including receptor tyrosine kinases, cytokine receptors, integrins and G-protein-coupled receptors. Evidence suggests that the Tec kinases influence a wide range of signaling pathways controlling activation of MAP kinases,actin reorganization, transcriptional regulation, cell survival and cellular transformation. Their impact on cellular physiology suggests that the Tec kinases help regulate multiple cellular processes beyond Ca2+mobilization.
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Affiliation(s)
- Aya Takesono
- National Human Genome Research Institute, 49 Convent Drive, 49/4A38, National Institutes of Health, Bethesda, MD 20892, USA
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Miller AT, Berg LJ. New insights into the regulation and functions of Tec family tyrosine kinases in the immune system. Curr Opin Immunol 2002; 14:331-40. [PMID: 11973131 DOI: 10.1016/s0952-7915(02)00345-x] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The Tec family of protein tyrosine kinases play an important role in signaling through antigen-receptors such as the TCR, BCR and Fcepsilon receptor. Recent studies have generated new insights into the domains in Tec kinases that take part in intramolecular and intermolecular binding. Furthermore, the consequences of these domain interactions for Tec activation and downregulation have been better defined. Genetic studies of kinase-knockout mice have emphasized the importance of Tec kinases in lymphocyte development, differentiation and apoptosis.
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Affiliation(s)
- Andrew T Miller
- Department of Pathology and Program in Immunology and Virology, University of Massachusetts Medical Center, Worcester, MA 01655, USA
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