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Guo Y, Sun CK, Tang L, Tan MS. Microglia PTK2B/Pyk2 in the Pathogenesis of Alzheimer's Disease. Curr Alzheimer Res 2023; 20:692-704. [PMID: 38321895 DOI: 10.2174/0115672050299004240129051655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Revised: 01/16/2024] [Accepted: 01/22/2024] [Indexed: 02/08/2024]
Abstract
Alzheimer's disease (AD) is a highly hereditary disease with complex genetic susceptibility factors. Extensive genome-wide association studies have established a distinct susceptibility link between the protein tyrosine kinase 2β (PTK2B) gene and late-onset Alzheimer's disease (LOAD), but the specific pathogenic mechanisms remain incompletely understood. PTK2B is known to be expressed in neurons, and recent research has revealed its more important significance in microglia. Elucidating the role of PTK2B high expression in microglia in AD's progression is crucial for uncovering novel pathogenic mechanisms of the disease. Our review of existing studies suggests a close relationship between PTK2B/proline-rich tyrosine kinase 2 (Pyk2) and tau pathology, and this process might be β-amyloid (Aβ) dependence. Pyk2 is hypothesized as a pivotal target linking Aβ and tau pathologies. Concurrently, Aβ-activated Pyk2 participates in the regulation of microglial activation and its proinflammatory functions. Consequently, it is reasonable to presume that Pyk2 in microglia contributes to amyloid-induced tau pathology in AD via a neuroinflammatory pathway. Furthermore, many things remain unclear, such as identifying the specific pathways that lead to the release of downstream inflammatory factors due to Pyk2 phosphorylation and whether all types of inflammatory factors can activate neuronal kinase pathways. Additionally, further in vivo experiments are essential to validate this hypothesized pathway. Considering PTK2B/Pyk2's potential role in AD pathogenesis, targeting this pathway may offer innovative and promising therapeutic approaches for AD.
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Affiliation(s)
- Yun Guo
- School of Clinical Medicine, Weifang Medical University, Weifang, China
| | - Cheng-Kun Sun
- Department of Neurology, Qingdao Municipal Hospital, Dalian Medical University, Qingdao, China
| | - Lian Tang
- Department of Neurology, Qingdao Municipal Hospital, Qingdao University, Qingdao, China
| | - Meng-Shan Tan
- School of Clinical Medicine, Weifang Medical University, Weifang, China
- Department of Neurology, Qingdao Municipal Hospital, Dalian Medical University, Qingdao, China
- Department of Neurology, Qingdao Municipal Hospital, Qingdao University, Qingdao, China
- Department of Neurology, Qingdao Municipal Hospital, University of Health and Rehabilitation Sciences, Qingdao, China
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2
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Day RN, Day KH, Pavalko FM. Direct visualization by FRET-FLIM of a putative mechanosome complex involving Src, Pyk2 and MBD2 in living MLO-Y4 cells. PLoS One 2021; 16:e0261660. [PMID: 34941939 PMCID: PMC8699642 DOI: 10.1371/journal.pone.0261660] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 12/08/2021] [Indexed: 01/12/2023] Open
Abstract
Earlier, we proposed the “mechanosome” concept as a testable model for understanding how mechanical stimuli detected by cell surface adhesion molecules are transmitted to modulate gene expression inside cells. Here, for the first time we document a putative mechanosome involving Src, Pyk2 and MBD2 in MLO-Y4 osteocytes with high spatial resolution using FRET-FLIM. Src-Pyk2 complexes were concentrated at the periphery of focal adhesions and the peri-nuclear region. Pyk2-MBD2 complexes were located primarily in the nucleus and peri-nuclear region. Lifetime measurements indicated that Src and MBD2 did not interact directly. Finally, mechanical stimulation by fluid flow induced apparent accumulation of Src-Pyk2 protein complexes in the peri-nuclear/nuclear region, consistent with the proposed behavior of a mechanosome in response to a mechanical stimulus.
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Affiliation(s)
- Richard N. Day
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Kathleen H. Day
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Fredrick M. Pavalko
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- * E-mail:
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3
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de Pins B, Mendes T, Giralt A, Girault JA. The Non-receptor Tyrosine Kinase Pyk2 in Brain Function and Neurological and Psychiatric Diseases. Front Synaptic Neurosci 2021; 13:749001. [PMID: 34690733 PMCID: PMC8527176 DOI: 10.3389/fnsyn.2021.749001] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 09/14/2021] [Indexed: 12/28/2022] Open
Abstract
Pyk2 is a non-receptor tyrosine kinase highly enriched in forebrain neurons. Pyk2 is closely related to focal adhesion kinase (FAK), which plays an important role in sensing cell contacts with extracellular matrix and other extracellular signals controlling adhesion and survival. Pyk2 shares some of FAK’s characteristics including recruitment of Src-family kinases after autophosphorylation, scaffolding by interacting with multiple partners, and activation of downstream signaling pathways. Pyk2, however, has the unique property to respond to increases in intracellular free Ca2+, which triggers its autophosphorylation following stimulation of various receptors including glutamate NMDA receptors. Pyk2 is dephosphorylated by the striatal-enriched phosphatase (STEP) that is highly expressed in the same neuronal populations. Pyk2 localization in neurons is dynamic, and altered following stimulation, with post-synaptic and nuclear enrichment. As a signaling protein Pyk2 is involved in multiple pathways resulting in sometimes opposing functions depending on experimental models. Thus Pyk2 has a dual role on neurites and dendritic spines. With Src family kinases Pyk2 participates in postsynaptic regulations including of NMDA receptors and is necessary for specific types of synaptic plasticity and spatial memory tasks. The diverse functions of Pyk2 are also illustrated by its role in pathology. Pyk2 is activated following epileptic seizures or ischemia-reperfusion and may contribute to the consequences of these insults whereas Pyk2 deficit may contribute to the hippocampal phenotype of Huntington’s disease. Pyk2 gene, PTK2B, is associated with the risk for late-onset Alzheimer’s disease. Studies of underlying mechanisms indicate a complex contribution with involvement in amyloid toxicity and tauopathy, combined with possible functional deficits in neurons and contribution in microglia. A role of Pyk2 has also been proposed in stress-induced depression and cocaine addiction. Pyk2 is also important for the mobility of astrocytes and glioblastoma cells. The implication of Pyk2 in various pathological conditions supports its potential interest for therapeutic interventions. This is possible through molecules inhibiting its activity or increasing it through inhibition of STEP or other means, depending on a precise evaluation of the balance between positive and negative consequences of Pyk2 actions.
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Affiliation(s)
- Benoit de Pins
- Institut du Fer à Moulin, Paris, France.,Inserm UMR-S 1270, Paris, France.,Faculté des Sciences et Ingénierie, Sorbonne Université, Paris, France
| | - Tiago Mendes
- Institut du Fer à Moulin, Paris, France.,Inserm UMR-S 1270, Paris, France.,Faculté des Sciences et Ingénierie, Sorbonne Université, Paris, France
| | - Albert Giralt
- Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Production and Validation Center of Advanced Therapies (Creatio), Faculty of Medicine and Health Science, University of Barcelona, Barcelona, Spain
| | - Jean-Antoine Girault
- Institut du Fer à Moulin, Paris, France.,Inserm UMR-S 1270, Paris, France.,Faculté des Sciences et Ingénierie, Sorbonne Université, Paris, France
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Naser R, Aldehaiman A, Díaz-Galicia E, Arold ST. Endogenous Control Mechanisms of FAK and PYK2 and Their Relevance to Cancer Development. Cancers (Basel) 2018; 10:E196. [PMID: 29891810 PMCID: PMC6025627 DOI: 10.3390/cancers10060196] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 05/31/2018] [Accepted: 06/06/2018] [Indexed: 02/07/2023] Open
Abstract
Focal adhesion kinase (FAK) and its close paralogue, proline-rich tyrosine kinase 2 (PYK2), are key regulators of aggressive spreading and metastasis of cancer cells. While targeted small-molecule inhibitors of FAK and PYK2 have been found to have promising antitumor activity, their clinical long-term efficacy may be undermined by the strong capacity of cancer cells to evade anti-kinase drugs. In healthy cells, the expression and/or function of FAK and PYK2 is tightly controlled via modulation of gene expression, competing alternatively spliced forms, non-coding RNAs, and proteins that directly or indirectly affect kinase activation or protein stability. The molecular factors involved in this control are frequently deregulated in cancer cells. Here, we review the endogenous mechanisms controlling FAK and PYK2, and with particular focus on how these mechanisms could inspire or improve anticancer therapies.
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Affiliation(s)
- Rayan Naser
- King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center (CBRC), Division of Biological and Environmental Sciences and Engineering (BESE), Thuwal 23955-6900, Saudi Arabia.
| | - Abdullah Aldehaiman
- King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center (CBRC), Division of Biological and Environmental Sciences and Engineering (BESE), Thuwal 23955-6900, Saudi Arabia.
| | - Escarlet Díaz-Galicia
- King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center (CBRC), Division of Biological and Environmental Sciences and Engineering (BESE), Thuwal 23955-6900, Saudi Arabia.
| | - Stefan T Arold
- King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center (CBRC), Division of Biological and Environmental Sciences and Engineering (BESE), Thuwal 23955-6900, Saudi Arabia.
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5
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Exploring the mechanistic insights of Cas scaffolding protein family member 4 with protein tyrosine kinase 2 in Alzheimer's disease by evaluating protein interactions through molecular docking and dynamic simulations. Neurol Sci 2018; 39:1361-1374. [PMID: 29789968 DOI: 10.1007/s10072-018-3430-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 04/26/2018] [Indexed: 01/02/2023]
Abstract
Cas scaffolding protein family member 4 and protein tyrosine kinase 2 are signaling proteins, which are involved in neuritic plaques burden, neurofibrillary tangles, and disruption of synaptic connections in Alzheimer's disease. In the current study, a computational approach was employed to explore the active binding sites of Cas scaffolding protein family member 4 and protein tyrosine kinase 2 proteins and their significant role in the activation of downstream signaling pathways. Sequential and structural analyses were performed on Cas scaffolding protein family member 4 and protein tyrosine kinase 2 to identify their core active binding sites. Molecular docking servers were used to predict the common interacting residues in both Cas scaffolding protein family member 4 and protein tyrosine kinase 2 and their involvement in Alzheimer's disease-mediated pathways. Furthermore, the results from molecular dynamic simulation experiment show the stability of targeted proteins. In addition, the generated root mean square deviations and fluctuations, solvent-accessible surface area, and gyration graphs also depict their backbone stability and compactness, respectively. A better understanding of CAS and their interconnected protein signaling cascade may help provide a treatment for Alzheimer's disease. Further, Cas scaffolding protein family member 4 could be used as a novel target for the treatment of Alzheimer's disease by inhibiting the protein tyrosine kinase 2 pathway.
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6
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Proline-Rich Protein Tyrosine Kinase 2 in Inflammation and Cancer. Cancers (Basel) 2018; 10:cancers10050139. [PMID: 29738483 PMCID: PMC5977112 DOI: 10.3390/cancers10050139] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 04/27/2018] [Accepted: 04/27/2018] [Indexed: 01/13/2023] Open
Abstract
Focal adhesion kinase (FAK) and its homologous FAK-related proline-rich tyrosine kinase 2 (Pyk2) contain the same domain, exhibit high sequence homology and are defined as a distinct family of non-receptor tyrosine kinases. This group of kinases plays critical roles in cytoskeletal dynamics and cell adhesion by regulating survival and growth signaling. This review summarizes the physiological and pathological functions of Pyk2 in inflammation and cancers. In particular, overexpression of Pyk2 in cancerous tissues is correlated with poor outcomes. Pyk2 stimulates multiple oncogenic signaling pathways, such as Wnt/β-catenin, PI3K/Akt, MAPK/ERK, and TGF-β/EGFR/VEGF, and facilitates carcinogenesis, migration, invasion, epithelial⁻mesenchymal transition and metastasis. Therefore, Pyk2 is a high-value therapeutic target and has clinical significance.
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7
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Huang H, Svoboda RA, Lazenby AJ, Saowapa J, Chaika N, Ding K, Wheelock MJ, Johnson KR. Up-regulation of N-cadherin by Collagen I-activated Discoidin Domain Receptor 1 in Pancreatic Cancer Requires the Adaptor Molecule Shc1. J Biol Chem 2016; 291:23208-23223. [PMID: 27605668 DOI: 10.1074/jbc.m116.740605] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Indexed: 12/13/2022] Open
Abstract
Pancreatic ductal adenocarcinomas are highly malignant cancers characterized by extensive invasion into surrounding tissues, metastasis to distant organs, and a limited response to therapy. A main feature of pancreatic ductal adenocarcinomas is desmoplasia, which leads to extensive deposition of collagen I. We have demonstrated that collagen I can induce epithelial-mesenchymal transition (EMT) in pancreatic cancer cells. A hallmark of EMT is an increase in the expression of the mesenchymal cadherin N-cadherin. Previously we showed up-regulation of N-cadherin promotes tumor cell invasion and that collagen I-induced EMT is mediated by two collagen receptors, α2β1-integrin and discoidin domain receptor 1 (DDR1). DDR1 is a receptor-tyrosine kinase widely expressed during embryonic development and in many adult tissues and is also highly expressed in many different cancers. In the signaling pathway initiated by collagen, we have shown proline-rich tyrosine kinase 2 (Pyk2) is downstream of DDR1. In this study we found isoform b of DDR1 is responsible for collagen I-induced up-regulation of N-cadherin and tyrosine 513 of DDR1b is necessary. Knocking down Shc1, which binds to tyrosine 513 of DDR1b via its PTB (phosphotyrosine binding) domain, eliminates the up-regulation of N-cadherin. The signaling does not require a functional SH2 domain or the tyrosine residues commonly phosphorylated in Shc1 but is mediated by the interaction between a short segment of the central domain of Shc1 and the proline-rich region of Pyk2. Taken together, these data illustrate DDR1b, but not DDR1a, mediates collagen I-induced N-cadherin up-regulation, and Shc1 is involved in this process by coupling to both DDR1 and Pyk2.
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Affiliation(s)
- Huocong Huang
- From the Department of Biochemistry and Molecular Biology, College of Medicine
| | | | - Audrey J Lazenby
- Department of Pathology and Microbiology, College of Medicine, and
| | | | - Nina Chaika
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha Nebraska 68198
| | - Ke Ding
- State Key Laboratory of Respiratory Diseases, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, #190 Kaiyuan Avenue, Guangzhou 510530, China, and
| | - Margaret J Wheelock
- From the Department of Biochemistry and Molecular Biology, College of Medicine.,Department of Oral Biology, College of Dentistry.,Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha Nebraska 68198
| | - Keith R Johnson
- From the Department of Biochemistry and Molecular Biology, College of Medicine, .,Department of Oral Biology, College of Dentistry.,Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha Nebraska 68198.,Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198
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8
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Cheung SMS, Ostergaard HL. Pyk2 Controls Integrin-Dependent CTL Migration through Regulation of De-Adhesion. THE JOURNAL OF IMMUNOLOGY 2016; 197:1945-56. [PMID: 27456486 DOI: 10.4049/jimmunol.1501505] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 06/24/2016] [Indexed: 11/19/2022]
Abstract
Protein tyrosine kinase 2 (Pyk2) is required for T cell adhesion to ICAM-1; however, the mechanism by which it regulates adhesion remains unexplored. Pyk2 function in murine CTL clones and activated ex vivo CD8(+) T cells was disrupted by pharmacological inhibition, knockdown of expression with small interfering RNA, or expression of the dominant-negative C-terminal domain. We found that Pyk2 is not absolutely required for adhesion of CTL to ICAM-1, but rather delays the initial adhesion. Disruption of Pyk2 function caused cells to display an unusual elongated appearance after 1 h on ICAM-1, consistent with abnormally strong adhesion. Furthermore, the random mobility of CTL on ICAM-1 was severely compromised using all three methods of disrupting Pyk2 function. Live-cell imaging studies revealed that the decreased migration is the result of a defect in the detachment from ICAM-1 at the trailing edge when Pyk2 function is inhibited. Examination of Pyk2 tyrosine phosphorylation in normal polarized cells demonstrated that Pyk2 phosphorylated at Y579 and Y580 preferentially localizes to the leading edge, whereas Y881-phosphorylated Pyk2 is enriched at the trailing edge, suggesting that the tyrosine phosphorylation of Pyk2 is spatially regulated in migrating CTL. Additionally, inhibition of Pyk2 caused cells to form multiple LFA-1-rich tails at the trailing edge, most likely resulting from a defect in LFA-1 release required for forward movement. Our results show that Pyk2 contributes to CTL migration by regulating detachment of CTL at the trailing edge, which could explain why Pyk2 is important for chemotactic and migratory responses.
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Affiliation(s)
- Samuel M S Cheung
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - Hanne L Ostergaard
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
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10
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Yue Y, Li ZN, Fang QG, Zhang X, Yang LL, Sun CF, Liu FY. The role of Pyk2 in the CCR7-mediated regulation of metastasis and viability in squamous cell carcinoma of the head and neck cells in vivo and in vitro. Oncol Rep 2015; 34:3280-7. [PMID: 26352169 DOI: 10.3892/or.2015.4269] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Accepted: 08/13/2015] [Indexed: 11/06/2022] Open
Abstract
In the present study, we aimed to demonstrate whether praline-rich tyrosine kinase-2 (Pyk2) participates in the chemokine receptor 7 (CCR7) downstream signaling network, and to determine the role of this molecule and the related mechanism in the CCR7-mediated regulation of viability and metastasis in vivo and in vitro of squamous cell carcinoma of the head and neck (SCCHN). We constructed the stable Pyk2 related non-kinase (PRNK)-expressing SCCHN cell line, and examined the viability, apoptosis, migration, invasion and adhesion ability in the transfected and untransfected SCCHN cells. An SCCHN tumor model in nude mice was designed and the tumor growth rate was assayed. E-cadherin and vimentin expression was assessed when Pyk2 was inactivated. We found that the stable PRNK-expressing SCCHN cells exhibited low viability, a high rate of apoptosis, low migratory ability, low invasive ability and low adhesion capacity. In the nude mouse body, the tumors formed by these cells grew slowly when compared to the tumor growth in the control group. When Pyk2 was inactivated, CCR7-induced E-cadherin and vimentin expression levels were altered. Thus, Pyk2 is a key downstream signaling molecules of CCR7 in SCCHN, which promotes SCCHN tumorigenesis and progression.
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Affiliation(s)
- Yang Yue
- Department of Orthodontics, School of Stomatology, China Medical University, Shenyang, Liaoning 110002, P.R. China
| | - Zhen-Ning Li
- Department of Oromaxillofacial‑Head and Neck Surgery, Department of Oral and Maxillofacial Surgery, School of Stomatology, China Medical University, Shenyang, Liaoning 110002, P.R. China
| | - Qi-Gen Fang
- Department of Head and Neck, Henan Tumor Hospital, Zhengzhou University, Zhengzhou, Henan 450008, P.R. China
| | - Xu Zhang
- Department of Head and Neck, Henan Tumor Hospital, Zhengzhou University, Zhengzhou, Henan 450008, P.R. China
| | - Liang-Liang Yang
- Department of Oral and Maxillofacial Surgery, The Fourth Affiliated Hospital of China Medical University, Shenyang, Liaoning 110002, P.R. China
| | - Chang-Fu Sun
- Department of Oromaxillofacial‑Head and Neck Surgery, Department of Oral and Maxillofacial Surgery, School of Stomatology, China Medical University, Shenyang, Liaoning 110002, P.R. China
| | - Fa-Yu Liu
- Department of Oromaxillofacial‑Head and Neck Surgery, Department of Oral and Maxillofacial Surgery, School of Stomatology, China Medical University, Shenyang, Liaoning 110002, P.R. China
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Dios-Esponera A, Isern de Val S, Sevilla-Movilla S, García-Verdugo R, García-Bernal D, Arellano-Sánchez N, Cabañas C, Teixidó J. Positive and negative regulation by SLP-76/ADAP and Pyk2 of chemokine-stimulated T-lymphocyte adhesion mediated by integrin α4β1. Mol Biol Cell 2015. [PMID: 26202465 PMCID: PMC4569313 DOI: 10.1091/mbc.e14-07-1246] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Stimulation by chemokines of integrin α4β1-dependent T-lymphocyte adhesion is a crucial step for lymphocyte trafficking. The adaptor Vav1 is required for chemokine-activated T-cell adhesion mediated by α4β1. Conceivably, proteins associating with Vav1 could potentially modulate this adhesion. Correlating with activation by the chemokine CXCL12 of T-lymphocyte attachment to α4β1 ligands, a transient stimulation in the association of Vav1 with SLP-76, Pyk2, and ADAP was observed. Using T-cells depleted for SLP-76, ADAP, or Pyk2, or expressing Pyk2 kinase-inactive forms, we show that SLP-76 and ADAP stimulate chemokine-activated, α4β1-mediated adhesion, whereas Pyk2 opposes T-cell attachment. While CXCL12-promoted generation of high-affinity α4β1 is independent of SLP-76, ADAP, and Pyk2, the strength of α4β1-VCAM-1 interaction and cell spreading on VCAM-1 are targets of regulation by these three proteins. GTPase assays, expression of activated or dominant-negative Rac1, or combined ADAP and Pyk2 silencing indicated that Rac1 activation by CXCL12 is a common mediator response in SLP-76-, ADAP-, and Pyk2-regulated cell adhesion involving α4β1. Our data strongly suggest that chemokine-stimulated associations between Vav1, SLP-76, and ADAP facilitate Rac1 activation and α4β1-mediated adhesion, whereas Pyk2 opposes this adhesion by limiting Rac1 activation.
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Affiliation(s)
- Ana Dios-Esponera
- Centro de Investigaciones Biológicas (CSIC), Department of Cellular and Molecular Medicine, 28040 Madrid, Spain
| | - Soledad Isern de Val
- Centro de Investigaciones Biológicas (CSIC), Department of Cellular and Molecular Medicine, 28040 Madrid, Spain
| | - Silvia Sevilla-Movilla
- Centro de Investigaciones Biológicas (CSIC), Department of Cellular and Molecular Medicine, 28040 Madrid, Spain
| | - Rosa García-Verdugo
- Centro de Investigaciones Biológicas (CSIC), Department of Cellular and Molecular Medicine, 28040 Madrid, Spain
| | - David García-Bernal
- Centro de Investigaciones Biológicas (CSIC), Department of Cellular and Molecular Medicine, 28040 Madrid, Spain
| | - Nohemí Arellano-Sánchez
- Centro de Investigaciones Biológicas (CSIC), Department of Cellular and Molecular Medicine, 28040 Madrid, Spain
| | - Carlos Cabañas
- Centro de Biología Molecular (CSIC), Department of Cell Biology and Immunology, Cantoblanco, 28049 Madrid, Spain
| | - Joaquin Teixidó
- Centro de Investigaciones Biológicas (CSIC), Department of Cellular and Molecular Medicine, 28040 Madrid, Spain
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Chapman NM, Houtman JCD. Functions of the FAK family kinases in T cells: beyond actin cytoskeletal rearrangement. Immunol Res 2015; 59:23-34. [PMID: 24816556 DOI: 10.1007/s12026-014-8527-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
T cells control the focus and extent of adaptive immunity in infectious and pathological diseases. The activation of T cells occurs when the T cell antigen receptor (TCR) and costimulatory and/or adhesion receptors are engaged by their ligands. This process drives signaling that promotes cytoskeletal rearrangement and transcription factor activation, both of which regulate the quality and magnitude of the T cell response. However, it is not fully understood how different receptor-induced signals combine to alter T cell activation. The related non-receptor tyrosine kinases focal adhesion kinase (FAK) and proline-rich tyrosine kinase 2 (Pyk2) are phosphorylated downstream of the TCR and several costimulatory and adhesion receptors. FAK family proteins integrate receptor-mediated signals that influence actin cytoskeletal rearrangement and effector T cell responses. In this review, we summarize the receptor-specific roles that FAK and Pyk2 control to influence T cell development and activation.
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Affiliation(s)
- Nicole M Chapman
- Interdisciplinary Graduate Program in Immunology, University of Iowa, Iowa City, IA, 52242, USA
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13
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Fang X, Liu X, Yao L, Chen C, Lin J, Ni P, Zheng X, Fan Q. New insights into FAK phosphorylation based on a FAT domain-defective mutation. PLoS One 2014; 9:e107134. [PMID: 25226367 PMCID: PMC4166415 DOI: 10.1371/journal.pone.0107134] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2014] [Accepted: 08/11/2014] [Indexed: 01/27/2023] Open
Abstract
Mounting evidence suggests that the FAK N-terminal (FERM) domain controls FAK phosphorylation and function; however, little is known regarding the role of the C terminal (FAT) domain in FAK regulation. We identified a patient-derived FAK mutant, in which a 27-amino acid segment was deleted from the C-terminal FAT domain (named FAK-Del33). When FAK-Del33 was overexpressed in specific tumor cell lines, Y397 phosphorylation increased compared with that observed in cells expressing FAK-WT. Here, we attempt to unveil the mechanism of this increased phosphorylation. Using cell biology experiments, we show that FAK-Del33 is incapable of co-localizing with paxillin, and has constitutively high Y397 phosphorylation. With a kinase-dead mutation, it showed phosphorylation of FAK-Del33 has enhanced through auto-phosphorylation. It was also demonstrated that phosphorylation of FAK-Del33 is not Src dependent or enhanced intermolecular interactions, and that the hyperphosphorylation can be lowered using increasing amounts of transfected FERM domain. This result suggests that Del33 mutation disrupting of FAT's structural integrity and paxillin binding capacity leads to incapable of targeting Focal adhesions, but has gained the capacity for auto-phosphorylation in cis.
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Affiliation(s)
- Xuqian Fang
- Department of Clinical Laboratory, Ruijin North Hospital, Ruijin Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, P. R. China
| | - Xiangfan Liu
- Faculty of Medical Laboratory Science, Shanghai JiaoTong University School of Medicine, Shanghai, P. R. China
| | - Ling Yao
- Department of Biochemistry and Molecular Biology, Shanghai JiaoTong University School of Medicine, Shanghai, P. R. China
| | - Changqiang Chen
- Department of Clinical Laboratory, Ruijin North Hospital, Ruijin Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, P. R. China
| | - Jiafei Lin
- Department of Clinical Laboratory, Ruijin North Hospital, Ruijin Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, P. R. China
| | - Peihua Ni
- Faculty of Medical Laboratory Science, Shanghai JiaoTong University School of Medicine, Shanghai, P. R. China
| | - Xinmin Zheng
- Department of Biochemistry and Molecular Biology, Shanghai JiaoTong University School of Medicine, Shanghai, P. R. China
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Qishi Fan
- Department of Clinical Laboratory, Ruijin North Hospital, Ruijin Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, P. R. China
- * E-mail:
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Takeishi Y. Pivotal roles of regulating the proline-rich tyrosine kinase 2 (PYK2) signaling in cardiac function and remodeling. J Mol Cell Cardiol 2014; 74:295-6. [DOI: 10.1016/j.yjmcc.2014.06.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 06/11/2014] [Accepted: 06/12/2014] [Indexed: 01/17/2023]
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How to find a leucine in a haystack? Structure, ligand recognition and regulation of leucine-aspartic acid (LD) motifs. Biochem J 2014; 460:317-29. [PMID: 24870021 DOI: 10.1042/bj20140298] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
LD motifs (leucine-aspartic acid motifs) are short helical protein-protein interaction motifs that have emerged as key players in connecting cell adhesion with cell motility and survival. LD motifs are required for embryogenesis, wound healing and the evolution of multicellularity. LD motifs also play roles in disease, such as in cancer metastasis or viral infection. First described in the paxillin family of scaffolding proteins, LD motifs and similar acidic LXXLL interaction motifs have been discovered in several other proteins, whereas 16 proteins have been reported to contain LDBDs (LD motif-binding domains). Collectively, structural and functional analyses have revealed a surprising multivalency in LD motif interactions and a wide diversity in LDBD architectures. In the present review, we summarize the molecular basis for function, regulation and selectivity of LD motif interactions that has emerged from more than a decade of research. This overview highlights the intricate multi-level regulation and the inherently noisy and heterogeneous nature of signalling through short protein-protein interaction motifs.
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Koshman YE, Chu M, Kim T, Kalmanson O, Farjah M, Kumar M, Lewis W, Geenen DL, de Tombe P, Goldspink PH, Solaro RJ, Samarel AM. Cardiomyocyte-specific expression of CRNK, the C-terminal domain of PYK2, maintains ventricular function and slows ventricular remodeling in a mouse model of dilated cardiomyopathy. J Mol Cell Cardiol 2014; 72:281-91. [PMID: 24713463 DOI: 10.1016/j.yjmcc.2014.03.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 02/22/2014] [Accepted: 03/29/2014] [Indexed: 01/06/2023]
Abstract
Up-regulation and activation of PYK2, a member of the FAK family of protein tyrosine kinases, is involved in the pathogenesis of left ventricular (LV) remodeling and heart failure (HF). PYK2 activation can be prevented by CRNK, the C-terminal domain of PYK2. We previously demonstrated that adenoviral-mediated CRNK gene transfer improved survival and LV function, and slowed LV remodeling in a rat model of coronary artery ligation-induced HF. We now interrogate whether cardiomyocyte-specific, transgenic CRNK expression prevents LV remodeling and HF in a mouse model of dilated cardiomyopathy (DCM) caused by constitutively active Protein Kinase Cε (caPKCε). Transgenic (TG; FVB/N background) mice were engineered to express rat CRNK under control of the α-myosin heavy chain promoter, and crossed with FVB/N mice with cardiomyocyte-specific expression of caPKCε to create double TG mice. LV structure, function, and gene expression were evaluated in all 4 groups (nonTG FVB/N; caPKCε(+/-); CRNK(+/-); and caPKCε×CRNK (PXC) double TG mice) at 1, 3, 6, 9 and 12mo of age. CRNK expression followed a Mendelian distribution, and CRNK mice developed and survived normally through 12mo. Cardiac structure, function and selected gene expression of CRNK mice were similar to nonTG littermates. CRNK had no effect on caPKCε expression and vice versa. PYK2 was up-regulated ~6-fold in caPKCε mice, who developed a non-hypertrophic, progressive DCM with reduced systolic (Contractility Index=151±5 vs. 90±4s(-1)) and diastolic (Tau=7.5±0.5 vs. 14.7±1.3ms) function, and LV dilatation (LV Remodeling Index (LVRI)=4.2±0.1 vs. 6.0±0.3 for FVB/N vs. caPKCε mice, respectively; P<0.05 for each at 12mo). In double TG PXC mice, CRNK expression significantly prolonged survival, improved contractile function (Contractile Index=115±8s(-1); Tau=9.5±1.0ms), and reduced LV remodeling (LVRI=4.9±0.1). Cardiomyocyte-specific expression of CRNK improves contractile function and slows LV remodeling in a mouse model of DCM.
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Affiliation(s)
- Yevgeniya E Koshman
- Department of Medicine, Loyola University Chicago Stritch School of Medicine, Maywood, IL 60153, USA
| | - Miensheng Chu
- Department of Cell and Molecular Physiology, Loyola University Chicago Stritch School of Medicine, Maywood, IL 60153, USA
| | - Taehoon Kim
- Department of Medicine, Loyola University Chicago Stritch School of Medicine, Maywood, IL 60153, USA
| | - Olivia Kalmanson
- Department of Cell and Molecular Physiology, Loyola University Chicago Stritch School of Medicine, Maywood, IL 60153, USA
| | - Mariam Farjah
- Department of Physiology and Biophysics, University of Illinois - Chicago, Chicago, IL 60612, USA
| | - Mohit Kumar
- Department of Cell and Molecular Physiology, Loyola University Chicago Stritch School of Medicine, Maywood, IL 60153, USA
| | - William Lewis
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - David L Geenen
- Department of Physiology and Biophysics, University of Illinois - Chicago, Chicago, IL 60612, USA
| | - Pieter de Tombe
- Department of Cell and Molecular Physiology, Loyola University Chicago Stritch School of Medicine, Maywood, IL 60153, USA
| | - Paul H Goldspink
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - R John Solaro
- Department of Physiology and Biophysics, University of Illinois - Chicago, Chicago, IL 60612, USA
| | - Allen M Samarel
- Department of Medicine, Loyola University Chicago Stritch School of Medicine, Maywood, IL 60153, USA; Department of Cell and Molecular Physiology, Loyola University Chicago Stritch School of Medicine, Maywood, IL 60153, USA.
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Kuang BH, Zhang MQ, Xu LH, Hu LJ, Wang HB, Zhao WF, Du Y, Zhang X. Proline-rich tyrosine kinase 2 and its phosphorylated form pY881 are novel prognostic markers for non-small-cell lung cancer progression and patients' overall survival. Br J Cancer 2013; 109:1252-63. [PMID: 23922106 PMCID: PMC3778294 DOI: 10.1038/bjc.2013.439] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 06/25/2013] [Accepted: 07/11/2013] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Our previous study revealed that proline-rich tyrosine kinase 2 (Pyk2) is implicated in both anchorage-independent growth and anoikis resistance in lung cancer cells. This study aims to explore the expression and clinical significance of Pyk2 and its phosphorylated forms in non-small-cell lung cancer (NSCLC). METHODS The mRNA and protein levels of Pyk2 or cancer stem cell markers (ALDH1a1, ABCG2 and Bmi-1) were either examined by reverse transcription-PCR or western blotting. An immunohistochemistry (IHC) assay was conducted to analyse the expression of Pyk2 and its phosphorylated forms in 128 NSCLC cases. RESULTS The levels of Pyk2 mRNA, total protein, and its phosphorylated form pY881 were higher in lung cancer lesions than in the paired noncancerous tissues. The IHC analysis showed the levels of the Pyk2 and Pyk2[pY881] proteins were highly expressed in 70 (54.7%) and 77 (60.2%) cases, respectively. Both Pyk2 and Pyk2[pY881] were independent prognostic factors for NSCLC patients. The gain and loss study of Pyk2 function revealed that Pyk2 could upregulate the expression of ALDH1a1, ABCG2 and Bmi-1 and enhance the ability of colony formation in soft agar assay in A549 and H460 cells. CONCLUSION Both Pyk2 and phosphorylated Pyk2[pY881] are potential prognostic factors and therapeutic targets for NSCLC.
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Affiliation(s)
- B-H Kuang
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, 651 East Dongfeng Road, Guangzhou 510060, China
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Ovcharenko A, Granot G, Shpilberg O, Raanani P. Retinoic acid induces adhesion and migration in NB4 cells through Pyk2 signaling. Leuk Res 2013; 37:956-62. [PMID: 23587524 DOI: 10.1016/j.leukres.2013.03.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 02/03/2013] [Accepted: 03/17/2013] [Indexed: 12/21/2022]
Abstract
Since the introduction of all-trans-retinoic acid (ATRA) treatment for acute promyelocytic leukemia (APL) there has been increasing concern about extramedullary disease (EMD) progression despite favorable response in the bone marrow. We postulated that ATRA treatment enhances migration and adhesion abilities possibly enabling APL cells to inhabit extramedullary sites. We revealed an increase in adhesion, migration and invasion capabilities of NB4 cells following ATRA treatment. ATRA induced upregulation of Pyk2 mRNA, protein and phosphorylation levels and enhanced Pyk2 interaction with paxillin and vinculin. Pyk2 inhibition resulted in a reduction of NB4 cell adhesion and migration following ATRA treatment. These results indicate that in vitro Pyk2 might function to regulate cell adhesion and motility following ATRA treatment and its upregulated expression may contribute to EMD development in APL patients.
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Affiliation(s)
- Adelina Ovcharenko
- Felsenstein Medical Research Center, Tel Aviv University, Petah Tikva, Israel
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McGinnis LK, Luo J, Kinsey WH. Protein tyrosine kinase signaling in the mouse oocyte cortex during sperm-egg interactions and anaphase resumption. Mol Reprod Dev 2013; 80:260-72. [PMID: 23401167 DOI: 10.1002/mrd.22160] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 02/01/2013] [Indexed: 02/06/2023]
Abstract
Fertilization triggers activation of a series of pre-programmed signal transduction pathways in the oocyte that establish a block to polyspermy, induce meiotic resumption, and initiate zygotic development. Fusion between sperm and oocyte results in rapid changes in oocyte intracellular free-calcium levels, which in turn activate multiple protein kinase cascades in the ooplasm. The present study examined the possibility that sperm-oocyte interaction involves localized activation of oocyte protein tyrosine kinases, which could provide an alternative signaling mechanism to that triggered by the fertilizing sperm. Confocal immunofluorescence analysis with antibodies to phosphotyrosine and phosphorylated protein tyrosine kinases allowed detection of minute signaling events localized to the site of sperm-oocyte interaction that were not amenable to biochemical analysis. The results provide evidence for localized accumulation of phosphotyrosine at the site of sperm contact, binding, or fusion, which suggests active protein tyrosine kinase signaling prior to and during sperm incorporation. The PYK2 kinase was found to be concentrated and activated at the site of sperm-oocyte interaction, and likely participates in this response. Widespread activation of PYK2 and FAK kinases was subsequently observed within the oocyte cortex, indicating that sperm incorporation is followed by more global signaling via these kinases during meiotic resumption. The results demonstrate an alternate signaling pathway triggered in mammalian oocytes by sperm contact, binding, or fusion with the oocyte.
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Affiliation(s)
- Lynda K McGinnis
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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20
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Faure C, Ramos M, Girault JA. Pyk2 cytonuclear localization: mechanisms and regulation by serine dephosphorylation. Cell Mol Life Sci 2013; 70:137-52. [PMID: 22802128 PMCID: PMC11113809 DOI: 10.1007/s00018-012-1075-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2012] [Revised: 06/13/2012] [Accepted: 06/25/2012] [Indexed: 11/25/2022]
Abstract
Cytonuclear signaling is essential for long-term alterations of cellular properties. Several pathways involving regulated nuclear accumulation of Ser/Thr kinases have been described but little is known about cytonuclear trafficking of tyrosine kinases. Proline-rich tyrosine kinase 2 (Pyk2) is a cytoplasmic non-receptor tyrosine kinase enriched in neurons and involved in functions ranging from synaptic plasticity to bone resorption, as well as in cancer. We previously showed the Ca(2+)-induced, calcineurin-dependent, nuclear localization of Pyk2. Here, we characterize the molecular mechanisms of Pyk2 cytonuclear localization in transfected PC12 cells. The 700-841 linker region of Pyk2 recapitulates its depolarization-induced nuclear accumulation. This region includes a nuclear export motif regulated by phosphorylation at residue S778, a substrate of cAMP-dependent protein kinase and calcineurin. Nuclear import is controlled by a previously identified sequence in the N-terminal domain and by a novel nuclear targeting signal in the linker region. Regulation of cytonuclear trafficking is independent of Pyk2 activity. The region regulating nuclear localization is absent from the non-neuronal shorter splice isoform of Pyk2. Our results elucidate the mechanisms of Ca(2+)-induced nuclear accumulation of Pyk2. They also suggest that Pyk2 nuclear accumulation is a novel type of signaling response that may contribute to specific long-term adaptations in neurons.
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Affiliation(s)
- Camille Faure
- Inserm, UMR-S 839, Institut du Fer à Moulin, 17 rue du Fer à Moulin, 75005 Paris, France
- Université Pierre et Marie Curie-Paris 6, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
| | - Mariana Ramos
- Inserm, UMR-S 839, Institut du Fer à Moulin, 17 rue du Fer à Moulin, 75005 Paris, France
- Université Pierre et Marie Curie-Paris 6, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
| | - Jean-Antoine Girault
- Inserm, UMR-S 839, Institut du Fer à Moulin, 17 rue du Fer à Moulin, 75005 Paris, France
- Université Pierre et Marie Curie-Paris 6, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
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21
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Omerovic J, Hammond DE, Prior IA, Clague MJ. Global snapshot of the influence of endocytosis upon EGF receptor signaling output. J Proteome Res 2012; 11:5157-66. [PMID: 22974187 DOI: 10.1021/pr3007304] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Trafficking of activated receptors may dictate the signaling output through the exposure to a changing palette of substrates and effectors. Here, we have used the acute application of a chemical inhibitor of dynamin activity, Dynasore, to inhibit internalization of activated EGF receptors together with quantitative mass spectrometry. This has generated a global snapshot of phosphorylation associated changes, which are contingent upon the endosomal trafficking of the activated EGF receptor. Using a SILAC approach, we have been able to quantitate >500 proteins in pTyr immunoprecipitation experiments and close to 800 individual phosphopeptides through affinity based enrichment strategies. This study provides >2 orders of magnitude increase in the coverage of potential EGF effectors than hitherto assessed in the context of endocytosis. There is a strong positive correlation between EGF responsiveness and sensitivity to Dynasore, with ~40% of EGF responses being significantly changed by endocytic inhibition. Proteins which are functionally linked to endosomal sorting are strongly influenced by receptor entry, suggesting that the activated receptor can govern its fate by influencing endosomal dynamics. However, the majority of EGF-responsive enzymes which we quantify, do not exhibit this property. Hence, our results provide many examples of key signaling proteins that are impervious to EGFR receptor endocytosis but nevertheless confirm the broad principle of endocytosis influence upon the network response.
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Affiliation(s)
- Jasminka Omerovic
- Department of Cellular and Molecular Physiology, Institute of Translational Research, University of Liverpool, Liverpool, L69 3BX, United Kingdom
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Kacena MA, Eleniste PP, Cheng YH, Huang S, Shivanna M, Meijome TE, Mayo LD, Bruzzaniti A. Megakaryocytes regulate expression of Pyk2 isoforms and caspase-mediated cleavage of actin in osteoblasts. J Biol Chem 2012; 287:17257-17268. [PMID: 22447931 DOI: 10.1074/jbc.m111.309880] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The proliferation and differentiation of osteoblast (OB) precursors are essential for elaborating the bone-forming activity of mature OBs. However, the mechanisms regulating OB proliferation and function are largely unknown. We reported that OB proliferation is enhanced by megakaryocytes (MKs) via a process that is regulated in part by integrin signaling. The tyrosine kinase Pyk2 has been shown to regulate cell proliferation and survival in a variety of cells. Pyk2 is also activated by integrin signaling and regulates actin remodeling in bone-resorbing osteoclasts. In this study, we examined the role of Pyk2 and actin in the MK-mediated increase in OB proliferation. Calvarial OBs were cultured in the presence of MKs for various times, and Pyk2 signaling cascades in OBs were examined by Western blotting, subcellular fractionation, and microscopy. We found that MKs regulate the temporal expression of Pyk2 and its subcellular localization. We also found that MKs regulate the expression of two alternatively spliced isoforms of Pyk2 in OBs, which may regulate OB differentiation and proliferation. MKs also induced cytoskeletal reorganization in OBs, which was associated with the caspase-mediated cleavage of actin, an increase in focal adhesions, and the formation of apical membrane ruffles. Moreover, BrdU incorporation in MK-stimulated OBs was blocked by the actin-polymerizing agent, jasplakinolide. Collectively, our studies reveal that Pyk2 and actin play an important role in MK-regulated signaling cascades that control OB proliferation and may be important for therapeutic interventions aimed at increasing bone formation in metabolic diseases of the skeleton.
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Affiliation(s)
- Melissa A Kacena
- Department of Orthopaedic Surgery, Indiana University School of Dentistry, Indianapolis, Indiana 46202.
| | - Pierre P Eleniste
- Department of Oral Biology, Indiana University School of Dentistry, Indianapolis, Indiana 46202
| | - Ying-Hua Cheng
- Department of Orthopaedic Surgery, Indiana University School of Dentistry, Indianapolis, Indiana 46202
| | - Su Huang
- Department of Oral Biology, Indiana University School of Dentistry, Indianapolis, Indiana 46202
| | - Mahesh Shivanna
- Department of Oral Biology, Indiana University School of Dentistry, Indianapolis, Indiana 46202
| | - Tomas E Meijome
- Department of Orthopaedic Surgery, Indiana University School of Dentistry, Indianapolis, Indiana 46202
| | - Lindsey D Mayo
- Herman B. Wells Center for Pediatric Research, Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indiana University School of Dentistry, Indianapolis, Indiana 46202
| | - Angela Bruzzaniti
- Department of Oral Biology, Indiana University School of Dentistry, Indianapolis, Indiana 46202.
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Block ER, Tolino MA, Klarlund JK. Extracellular ATP stimulates epithelial cell motility through Pyk2-mediated activation of the EGF receptor. Cell Signal 2011; 23:2051-5. [PMID: 21840393 DOI: 10.1016/j.cellsig.2011.07.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Revised: 07/25/2011] [Accepted: 07/26/2011] [Indexed: 11/25/2022]
Abstract
Wounding usually causes considerable cell damage, and released ATP promotes migration of nearby epithelium. ATP binds to purinergic receptors on the cell surface and induces transactivation of the EGF receptor through signaling by the Src family kinases (SFKs). Here we tested whether ATP activates these kinases through Pyk2, a member of the focal adhesion kinase family. Pyk2 was rapidly and potently activated by treating corneal epithelial cells with ATP, and physical interaction of Pyk2 with the SFKs was enhanced. Disruption of Pyk2 signaling either by siRNA or by expression of a dominant-negative mutant led to inhibition of ATP-induced activation of the SFKs and the EGF receptor. Inhibiting Pyk2 activity also blocked ATP stimulation of healing of wounds in epithelial cell sheets. These data suggest that ATP stimulates sequential activation of Pyk2, SFKs, and the EGF receptor to induce cell migration.
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Affiliation(s)
- Ethan R Block
- Ophthalmology and Visual Sciences Research Center, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
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St-Pierre J, Lysechko TL, Ostergaard HL. Hypophosphorylated and inactive Pyk2 associates with paxillin at the microtubule organizing center in hematopoietic cells. Cell Signal 2011; 23:718-30. [DOI: 10.1016/j.cellsig.2010.12.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Revised: 12/13/2010] [Accepted: 12/21/2010] [Indexed: 10/18/2022]
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Non-overlapping functions for Pyk2 and FAK in osteoblasts during fluid shear stress-induced mechanotransduction. PLoS One 2011; 6:e16026. [PMID: 21283581 PMCID: PMC3026802 DOI: 10.1371/journal.pone.0016026] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Accepted: 12/03/2010] [Indexed: 11/25/2022] Open
Abstract
Mechanotransduction, the process by which cells convert external mechanical stimuli such as fluid shear stress (FSS) into biochemical changes, plays a critical role in maintenance of the skeleton. We have proposed that mechanical stimulation by FSS across the surfaces of bone cells results in formation of unique signaling complexes called mechanosomes that are launched from sites of adhesion with the extracellular matrix and with other bone cells [1]. Deformation of adhesion complexes at the cell membrane ultimately results in alteration of target gene expression. Recently, we reported that focal adhesion kinase (FAK) functions as a part of a mechanosome complex that is required for FSS-induced mechanotransduction in bone cells. This study extends this work to examine the role of a second member of the FAK family of non-receptor protein tyrosine kinases, proline-rich tyrosine kinase 2 (Pyk2), and determine its role during osteoblast mechanotransduction. We use osteoblasts harvested from mice as our model system in this study and compared the contributions of Pyk2 and FAK during FSS induced mechanotransduction in osteoblasts. We exposed Pyk2+/+ and Pyk2−/− primary calvarial osteoblasts to short period of oscillatory fluid flow and analyzed downstream activation of ERK1/2, and expression of c-fos, cyclooxygenase-2 and osteopontin. Unlike FAK, Pyk2 was not required for fluid flow-induced mechanotransduction as there was no significant difference in the response of Pyk2+/+ and Pyk2−/− osteoblasts to short periods of fluid flow (FF). In contrast, and as predicted, FAK−/− osteoblasts were unable to respond to FF. These data indicate that FAK and Pyk2 have distinct, non-redundant functions in launching mechanical signals during osteoblast mechanotransduction. Additionally, we compared two methods of generating FF in both cell types, oscillatory pump method and another orbital platform method. We determined that both methods of generating FF induced similar responses in both primary calvarial osteoblasts and immortalized calvarial osteoblasts.
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Al-Shami A, Wilkins C, Crisostomo J, Seshasayee D, Martin F, Xu N, Suwanichkul A, Anderson SJ, Oravecz T. The adaptor protein Sh2d3c is critical for marginal zone B cell development and function. THE JOURNAL OF IMMUNOLOGY 2010; 185:327-34. [PMID: 20505138 DOI: 10.4049/jimmunol.1000096] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Sh2d3c is an adaptor protein that has been implicated in T cell activation and shown to associate with different components of the integrin signaling pathway ex vivo. However, the in vivo significance of Sh2d3c expression in the regulation of the immune response and/or hematopoietic cell lineage development is not known. In this study, we show that expression of Sh2d3c is more critical for development and function of marginal zone B (MZB) cells than for T cell maturation. Mice deficient in Sh2d3c expression (Sh2d3c(-/-)) had a reduced number of MZB cells, and the residual MZB cells failed to properly capture polysaccharide Ags. Activation-induced proliferation, cytokine production, and migration of Sh2d3c(-)(/)(-) splenic B cells were also significantly reduced in vitro compared with wild-type (Sh2d3c(+/+)) cells. In contrast, T cell development and function were largely normal in Sh2d3c(-/-) mice. The thymi of Sh2d3c(-/-) mice showed no maturational abnormalities, the number of splenic T cells was only modestly reduced, and the T cells responded normally to in vitro polyclonal activation. The observed B cell deficiency in the Sh2d3c(-/-) mice led to diminished humoral immune response against thymus-independent type 2, but not thymus-dependent Ags, which highlights the primary in vivo role of Sh2d3c in regulating B cell development and function.
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Affiliation(s)
- Amin Al-Shami
- Lexicon Pharmaceuticals, The Woodlands, TX 77381, USA.
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28
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Block ER, Tolino MA, Klarlund JK. Pyk2 activation triggers epidermal growth factor receptor signaling and cell motility after wounding sheets of epithelial cells. J Biol Chem 2010; 285:13372-9. [PMID: 20215112 DOI: 10.1074/jbc.m109.083089] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Activation of the epidermal growth factor receptor (EGFR) is a key signaling event that promotes cells to move and cover wounds in many epithelia. We have previously shown that wounding activates the EGFR through activation of the Src family kinases (SFKs), which induce proteolytic shedding of epidermal growth factor-like ligands from the cell surface. A major goal in wound healing research is to identify early signals that promote motility, and here we examined the hypothesis that members of the focal adhesion kinase family are upstream activators of the SFKs after wounding. We found that focal adhesion kinase is not activated by wounding but that a different family member, Pyk2 (PTK2B/RAFTK/CAKbeta), is activated rapidly and potently. Pyk2 interaction with c-Src is increased after wounding, as determined by co-immunoprecipitation experiments. Disruption of Pyk2 signaling either by small interfering RNA or by expression of a dominant negative mutant led to inhibition of wound-induced activation of the SFKs and the EGFR, and conversely, overexpression of wild-type Pyk2 stimulated SFK and EGFR kinase activities in cells. In wound healing studies, Pyk2 small interfering RNA or dominant negative inhibited cell migration. These results show that activation of Pyk2 is an early signal that promotes wound healing by stimulating the SFK/EGFR signaling pathway.
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Affiliation(s)
- Ethan R Block
- Ophthalmology and Visual Sciences Research Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA
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Abstract
IMPORTANCE OF THE FIELD The focal adhesion tyrosine kinases FAK and Pyk2 are uniquely situated to act as critical mediators for the activation of signaling pathways that regulate cell migration, proliferation and survival. By coordinating adhesion and cytoskeletal dynamics with survival and growth signaling, FAK and Pyk2 represent molecular therapeutic targets in cancer as malignant cells often exhibit defects in these processes. AREAS COVERED IN THIS REVIEW This review examines the structure and function of the focal adhesion kinase Pyk2 and intends to provide a rationale for the employment of modulating strategies that include both catalytic and extra-catalytic approaches that have been developed in the last 3 - 5 years. WHAT THE READER WILL GAIN Targeting tyrosine kinases in oncology has focused on the ATP binding pocket as means to inhibit catalytic activity and downregulate pathways involved in tumor invasion. This review discusses the available catalytic inhibitors and compares them to the alternative approach of targeting protein-protein interactions that regulate kinase activity. TAKE HOME MESSAGE Development of specific catalytic inhibitors of the focal adhesion kinases has improved but significant challenges remain. Thus, approaches that inhibit the effector function of Pyk2 by targeting regulatory modules can increase specificity and will be a welcome asset to the therapeutic arena.
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Affiliation(s)
- Christopher A Lipinski
- Mayo Clinic Collaborative Research Building, Department of Biochemistry and Molecular Biology, Scottsdale, AZ 85259, USA
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Tse KWK, Dang-Lawson M, Lee RL, Vong D, Bulic A, Buckbinder L, Gold MR. B cell receptor-induced phosphorylation of Pyk2 and focal adhesion kinase involves integrins and the Rap GTPases and is required for B cell spreading. J Biol Chem 2009; 284:22865-77. [PMID: 19561089 DOI: 10.1074/jbc.m109.013169] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Signaling by the B cell receptor (BCR) promotes integrin-mediated adhesion and cytoskeletal reorganization. This results in B cell spreading, which enhances the ability of B cells to bind antigens and become activated. Proline-rich tyrosine kinase (Pyk2) and focal adhesion kinase (FAK) are related cytoplasmic tyrosine kinases that regulate cell adhesion, cell morphology, and cell migration. In this report we show that BCR signaling and integrin signaling collaborate to induce the phosphorylation of Pyk2 and FAK on key tyrosine residues, a modification that increases the kinase activity of Pyk2 and FAK. Activation of the Rap GTPases is critical for BCR-induced integrin activation as well as for BCR- and integrin-induced reorganization of the actin cytoskeleton. We now show that Rap activation is essential for BCR-induced phosphorylation of Pyk2 and for integrin-induced phosphorylation of Pyk2 and FAK. Moreover Rap-dependent phosphorylation of Pyk2 and FAK required an intact actin cytoskeleton as well as actin dynamics, suggesting that Rap regulates Pyk2 and FAK via its effects on the actin cytoskeleton. Importantly B cell spreading induced by BCR/integrin co-stimulation or by integrin engagement was inhibited by short hairpin RNA-mediated knockdown of either Pyk2 or FAK expression and by treatment with PF-431396, a chemical inhibitor that blocks the kinase activities of both Pyk2 and FAK. Thus Pyk2 and FAK are downstream targets of the Rap GTPases that play a key role in regulating B cell morphology.
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Affiliation(s)
- Kathy W K Tse
- Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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A Pyk2-Vav1 complex is recruited to beta3-adhesion sites to initiate Rho activation. Biochem J 2009; 420:49-56. [PMID: 19207108 DOI: 10.1042/bj20090037] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Integrin alphavbeta3-mediated adhesion of haemopoietic cells to vitronectin results in beta3 tyrosine phosphorylation and Rho activation which is necessary for adhesion. Previously, we have shown that the RhoGEF (Rho guanine-nucleotide-exchange factor) Vav1 could associate indirectly with alphavbeta3 during leucocyte adhesion to vitronectin. In the present study, we have identified the non-receptor tyrosine kinase Pyk2 (proline-rich tyrosine kinase 2) as the adaptor protein that links Vav1 with alphavbeta3. The association of Pyk2 and Vav1 with beta3 relies on the presence of Tyr747 in beta3, the primary site of beta3 phosphorylation. However, association of Pyk2 with Vav1 is independent of beta3 tyrosine phosphorylation. Formation of a Pyk2-Vav1 complex occurs upon cell adhesion and Pro717 of Pyk2 plays a key role in Pyk2 interaction with Vav1. Utilizing purified recombinant proteins, we confirmed the direct interaction between Pyk2 and Vav1 In vitro. Cells transfected with GFP (green fluorescent protein)-Pyk2-P717A demonstrated severely suppressed cytoskeletal reorganization, impaired Vav1 recruitment, decreased Rho GTPase activation and loss of cell adhesion. Using siRNA (small interfering RNA) to specifically reduce Pyk2 levels in cells resulted in disrupted association between Vav1 and beta3 and impaired cell adhesion. These results indicate that Pyk2 is a critical signalling molecule downstream of beta3 integrin tyrosine phosphorylation and mediates Vav1 recruitment to accomplish actin reorganization necessary for adhesion.
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PP2 Regulates Human Trophoblast Cells Differentiation by Activating p38 and ERK1/2 and Inhibiting FAK Activation. Placenta 2008; 29:862-70. [DOI: 10.1016/j.placenta.2008.07.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2008] [Revised: 07/26/2008] [Accepted: 07/30/2008] [Indexed: 10/21/2022]
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Sun CK, Man K, Ng KT, Ho JW, Lim ZX, Cheng Q, Lo CM, Poon RT, Fan ST. Proline-rich tyrosine kinase 2 (Pyk2) promotes proliferation and invasiveness of hepatocellular carcinoma cells through c-Src/ERK activation. Carcinogenesis 2008; 29:2096-105. [PMID: 18765415 DOI: 10.1093/carcin/bgn203] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The aim of the current study is to elucidate the mechanism of proline-rich tyrosine kinase 2 (Pyk2)-mediated cell proliferation and invasiveness in hepatocellular carcinoma (HCC) cells. Human HCC cell lines PLC and MHCC97L were stably transfected with either full-length Pyk2 or C-terminal non-kinase region of Pyk2 (PRNK). Functional studies on cell proliferation and invasion were conducted in vitro by colony formation assay, adhesion assay, migration assay and wound-healing assay. For the in vivo study, an orthotopic nude mice liver tumor model was applied to investigate the effects of Pyk2 overexpression on tumor growth and metastasis. Overexpression of Pyk2 in PLC cells resulted in an upregulation of colony formation (P = 0.021) and adhesion toward laminin (P = 0.018). Pyk2 promoted wound recovery by stimulation of actin stress fiber polymerization. In the in vivo study, transfection of PRNK in MHCC97L cells significantly decreased tumor volume (P = 0.001) and the incidence of lung metastasis (P = 0.014). Overexpression of Pyk2 promoted the activation of c-Src, formation of Pyk2/c-Src complex and activated the extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK)-signaling pathway. Pyk2 upregulated the activation of ERK1/2 that is insensitive to MAPK/ERK kinase (MEK)1/2 inhibition. On the contrary, PRNK overexpression downregulated the activation of c-Src and ERK/MAPK-signaling pathways. Immunofluorescence staining showed that the focal adhesion localization of Pyk2 is a major determinant for c-Src and ERK/MAPK activation. In conclusion, our results showed that Pyk2 promoted cell proliferation and invasiveness by upregulation of the c-Src and ERK/MAPK-signaling pathways.
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Affiliation(s)
- Chris K Sun
- Department of Surgery and Centre for Cancer Research, The University of Hong Kong, Pokfulam, Hong Kong, China
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Hart DL, Heidkamp MC, Iyengar R, Vijayan K, Szotek EL, Barakat JA, Leya M, Henze M, Scrogin K, Henderson KK, Samarel AM. CRNK gene transfer improves function and reverses the myosin heavy chain isoenzyme switch during post-myocardial infarction left ventricular remodeling. J Mol Cell Cardiol 2008; 45:93-105. [PMID: 18495152 DOI: 10.1016/j.yjmcc.2008.04.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2007] [Revised: 04/01/2008] [Accepted: 04/07/2008] [Indexed: 12/17/2022]
Abstract
PYK2 is a Ca(2+)-dependent, nonreceptor protein tyrosine kinase that is involved in the induction of left ventricular hypertrophy (LVH) and its transition to heart failure. We and others have previously investigated PYK2's function in vitro using cultured neonatal and adult rat ventricular myocytes as model systems. However, the function of PYK2 in the in vivo adult heart remains unclear. Here we evaluate the effect of PYK2 inhibition following myocardial infarction (MI) using adenoviral (Adv) overexpression of the C-terminal domain of PYK2, known as CRNK. First we demonstrate that CRNK functions as a dominant-negative inhibitor of PYK2-dependent signaling, presumably by displacing PYK2 from focal adhesions and costameres. Then, male Sprague-Dawley rats (~300 g) underwent permanent left anterior descending coronary artery ligation. One wk post-MI, either Adv-GFP (n=34) or Adv-CRNK (n=28) was administered (10(10) pfu, 0.1 ml) via catheter-based, Optison-mediated gene transfer. LV structure and function were evaluated by echocardiography 1 and 3 wk after gene transfer, and LV tissue was analyzed by real-time RT-PCR and Western blotting. CRNK overexpression was readily detected by Western blotting 1 wk following gene transfer. Adv-CRNK improved overall survival (P=0.03; Logrank Test) and LV fractional shortening (23+/-2% vs. 31+/-2% for Adv-GFP vs. Adv-CRNK infected animals, respectively; P<0.05). Whereas MI hearts exhibited increased beta-, and decreased alpha-myosin heavy chain (MHC) mRNA expression characteristic of LVH, Adv-CRNK reversed the MHC isoenzyme switch (3.3+/-1.4 fold increase in alpha MHC; 0.4+/-0.1 fold decrease in beta MHC; P<0.05 for both). In summary, CRNK gene transfer improves survival, increases LV function, and alters MHC gene expression suggesting an attenuation of LV remodeling post-MI.
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Affiliation(s)
- Davin L Hart
- The Cardiovascular Institute, Department of Medicine, Loyola University Chicago Stritch School of Medicine, Maywood, Illinois 60153, USA
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Zhu X, Boetticher E, Wang L, Duan Y, Learoyd J, Leff AR. Proline-rich tyrosine kinase 2 regulates spreading and migration of eosinophils after beta2-integrin adhesion. Am J Respir Cell Mol Biol 2008; 39:263-9. [PMID: 18367725 DOI: 10.1165/rcmb.2008-0047oc] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We examined the role of proline-rich tyrosine kinase (Pyk) 2 in the spreading and migration of human blood eosinophils after beta(2)-integrin ligation. Western blot analysis showed that Pyk2 was activated by phosphorylation at Y402 after eosinophil adhesion to BSA-coated plates after activation with IL-5, platelet-activating factor (PAF), formyl-met-leu-phe (fMLP), or Mn(2)(+). To determine the role of Pyk2 in regulating eosinophil migration, we used a transducable dominant-negative inhibitor of Pyk2, TAT-mediated protein transduction of dominant-negative C-terminal Pyk2 (TAT-Pyk2-CT), a fusion protein in which TAT peptide was fused to the C-terminal Pyk2. TAT-Pyk2-CT blocked tyrosine phosphorylation of Pyk2 caused by beta(2)-integrin adhesion, but did not block adhesion of eosinophils to plated BSA. TAT-Pyk2-CT also blocked subsequent spreading and migration of eosinophils caused by IL-5, PAF, or fMLP. Spreading eosinophils stained with FITC-conjugated phalloidin showed elongation and formation of multiple fillopodia and lamellipodia, whereas nonspreading eosinophils were smaller and round. Treatment of eosinophils with TAT-Pyk2-CT had no effect on the initial cell polarization, but blocked the formation of fillopodia and lamellipodia in adherent cells. Migration of eosinophils through Transwell plates caused by IL-5, PAF, or fMLP was blocked significantly after inhibition of Pyk2. These data indicate that Pyk2, although not involved in beta(2)-integrin adhesion, causes eosinophil spreading and regulates subsequent chemotactic migration after beta(2)-integrin ligation to endothelial counter ligands. We conclude that Pyk2 is activated by beta(2)-integrin adhesion and is a required signal for eosinophil spreading and subsequent chemotactic migration.
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Affiliation(s)
- Xiangdong Zhu
- Section of Pulmonary and Critical Care Medicine, Department of Medicine, MC6076, University of Chicago, 5841 South Maryland Avenue, Chicago, IL 60637, USA.
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Gil-Henn H, Destaing O, Sims NA, Aoki K, Alles N, Neff L, Sanjay A, Bruzzaniti A, De Camilli P, Baron R, Schlessinger J. Defective microtubule-dependent podosome organization in osteoclasts leads to increased bone density in Pyk2(-/-) mice. ACTA ACUST UNITED AC 2007; 178:1053-64. [PMID: 17846174 PMCID: PMC2064627 DOI: 10.1083/jcb.200701148] [Citation(s) in RCA: 192] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The protein tyrosine kinase Pyk2 is highly expressed in osteoclasts, where it is primarily localized in podosomes. Deletion of Pyk2 in mice leads to mild osteopetrosis due to impairment in osteoclast function. Pyk2-null osteoclasts were unable to transform podosome clusters into a podosome belt at the cell periphery; instead of a sealing zone only small actin rings were formed, resulting in impaired bone resorption. Furthermore, in Pyk2-null osteoclasts, Rho activity was enhanced while microtubule acetylation and stability were significantly reduced. Rescue experiments by ectopic expression of wild-type or a variety of Pyk2 mutants in osteoclasts from Pyk2−/− mice have shown that the FAT domain of Pyk2 is essential for podosome belt and sealing zone formation as well as for bone resorption. These experiments underscore an important role of Pyk2 in microtubule-dependent podosome organization, bone resorption, and other osteoclast functions.
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Affiliation(s)
- Hava Gil-Henn
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06511, USA
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Buckbinder L, Crawford DT, Qi H, Ke HZ, Olson LM, Long KR, Bonnette PC, Baumann AP, Hambor JE, Grasser WA, Pan LC, Owen TA, Luzzio MJ, Hulford CA, Gebhard DF, Paralkar VM, Simmons HA, Kath JC, Roberts WG, Smock SL, Guzman-Perez A, Brown TA, Li M. Proline-rich tyrosine kinase 2 regulates osteoprogenitor cells and bone formation, and offers an anabolic treatment approach for osteoporosis. Proc Natl Acad Sci U S A 2007; 104:10619-24. [PMID: 17537919 PMCID: PMC1880863 DOI: 10.1073/pnas.0701421104] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Bone is accrued and maintained primarily through the coupled actions of bone-forming osteoblasts and bone-resorbing osteoclasts. Cumulative in vitro studies indicated that proline-rich tyrosine kinase 2 (PYK2) is a positive mediator of osteoclast function and activity. However, our investigation of PYK2-/- mice did not reveal evidence supporting an essential function for PYK2 in osteoclasts either in vivo or in culture. We find that PYK2-/- mice have high bone mass resulting from an unexpected increase in bone formation. Consistent with the in vivo findings, mouse bone marrow cultures show that PYK2 deficiency enhances differentiation and activity of osteoprogenitor cells, as does expressing a PYK2-specific short hairpin RNA or dominantly interfering proteins in human mesenchymal stem cells. Furthermore, the daily administration of a small-molecule PYK2 inhibitor increases bone formation and protects against bone loss in ovariectomized rats, an established preclinical model of postmenopausal osteoporosis. In summary, we find that PYK2 regulates the differentiation of early osteoprogenitor cells across species and that inhibitors of the PYK2 have potential as a bone anabolic approach for the treatment of osteoporosis.
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Park SY, Li H, Avraham S. RAFTK/Pyk2 regulates EGF-induced PC12 cell spreading and movement. Cell Signal 2007; 19:289-300. [PMID: 16945503 DOI: 10.1016/j.cellsig.2006.07.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2006] [Revised: 06/29/2006] [Accepted: 07/04/2006] [Indexed: 01/13/2023]
Abstract
The protein tyrosine kinase RAFTK, also termed Pyk2, is a member of the focal adhesion kinase (FAK) subfamily. In this report, we show the role of RAFTK in neuroendocrine PC12 cells upon epidermal growth factor (EGF) stimulation. Following EGF treatment, we observed that RAFTK was tyrosine-phosphorylated in a time- and dose-dependent manner, while FAK was constitutively phosphorylated and primarily regulated by cell adhesion. Moreover, we found that RAFTK associated with the phosphorylated EGF receptor (EGFR) upon EGF stimulation. RAFTK phosphorylation was mediated primarily through PLCgamma-IP3-Ca(2+) signaling and partially through PI3-Kinase. Furthermore, overexpression of PRNK, a specific dominant-negative construct of RAFTK, was sufficient to block EGF-induced cell spreading and movement. Paxillin, a key modulator of the actin cytoskeleton and an RAFTK substrate, was also phosphorylated following EGF treatment. EGF induced a dynamic reorganization of RAFTK and paxillin at neuronal adhesion sites, with the specific localization of paxillin at the inner juxtaposition of RAFTK. Additionally, we observed that RAFTK associated with the scaffold protein c-Cbl and mediated its phosphorylation. Our data demonstrate that while FAK mediated cell adhesion, RAFTK was localized at the cytoplasm where it mediated inside-out signaling through intracellular Ca(2+), thus leading to cell spreading and movement upon EGF stimulation.
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Affiliation(s)
- Shin-Young Park
- Division of Experimental Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Harvard Institutes of Medicine, 4 Blackfan Circle, Boston, MA 02215, USA
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Corsi JM, Rouer E, Girault JA, Enslen H. Organization and post-transcriptional processing of focal adhesion kinase gene. BMC Genomics 2006; 7:198. [PMID: 16889663 PMCID: PMC1570463 DOI: 10.1186/1471-2164-7-198] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2006] [Accepted: 08/04/2006] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase critical for processes ranging from embryo development to cancer progression. Although isoforms with specific molecular and functional properties have been characterized in rodents and chicken, the organization of FAK gene throughout phylogeny and its potential to generate multiple isoforms are not well understood. Here, we study the phylogeny of FAK, the organization of its gene, and its post-transcriptional processing in rodents and human. RESULTS A single orthologue of FAK and the related PYK2 was found in non-vertebrate species. Gene duplication probably occurred in deuterostomes after the echinoderma embranchment, leading to the evolution of PYK2 with distinct properties. The amino acid sequence of FAK and PYK2 is conserved in their functional domains but not in their linker regions, with the absence of autophosphorylation site in C. elegans. Comparison of mouse and human FAK genes revealed the existence of multiple combinations of conserved and non-conserved 5'-untranslated exons in FAK transcripts suggesting a complex regulation of their expression. Four alternatively spliced coding exons (13, 14, 16, and 31), previously described in rodents, are highly conserved in vertebrates. Cis-regulatory elements known to regulate alternative splicing were found in conserved alternative exons of FAK or in the flanking introns. In contrast, other reported human variant exons were restricted to Homo sapiens, and, in some cases, other primates. Several of these non-conserved exons may correspond to transposable elements. The inclusion of conserved alternative exons was examined by RT-PCR in mouse and human brain during development. Inclusion of exons 14 and 16 peaked at the end of embryonic life, whereas inclusion of exon 13 increased steadily until adulthood. Study of various tissues showed that inclusion of these exons also occurred, independently from each other, in a tissue-specific fashion. CONCLUSION The alternative coding exons 13, 14, 16, and 31 are highly conserved in vertebrates and their inclusion in mRNA is tightly but independently regulated. These exons may therefore be crucial for FAK function in specific tissues or during development. Conversely pathological disturbance of the expression of FAK and of its isoforms could lead to abnormal cellular regulation.
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Affiliation(s)
- Jean-Marc Corsi
- Unité Mixte de Recherche-Santé (UMR-S) 536, Institut National de la Santé et de la Recherche Médicale (INSERM) F-75005, Paris, France; Université Pierre et Marie Curie-Paris 6, F-75005, Paris, France; Institut du Fer-à-Moulin, F-75005, Paris, France
| | - Evelyne Rouer
- Unité Mixte de Recherche-Santé (UMR-S) 536, Institut National de la Santé et de la Recherche Médicale (INSERM) F-75005, Paris, France; Université Pierre et Marie Curie-Paris 6, F-75005, Paris, France; Institut du Fer-à-Moulin, F-75005, Paris, France
| | - Jean-Antoine Girault
- Unité Mixte de Recherche-Santé (UMR-S) 536, Institut National de la Santé et de la Recherche Médicale (INSERM) F-75005, Paris, France; Université Pierre et Marie Curie-Paris 6, F-75005, Paris, France; Institut du Fer-à-Moulin, F-75005, Paris, France
| | - Hervé Enslen
- Unité Mixte de Recherche-Santé (UMR-S) 536, Institut National de la Santé et de la Recherche Médicale (INSERM) F-75005, Paris, France; Université Pierre et Marie Curie-Paris 6, F-75005, Paris, France; Institut du Fer-à-Moulin, F-75005, Paris, France
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Alier KA, Morris BJ. Divergent regulation of Pyk2/CAKbeta phosphorylation by Ca2+ and cAMP in the hippocampus. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1745:342-9. [PMID: 16120467 DOI: 10.1016/j.bbamcr.2005.04.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2005] [Revised: 04/06/2005] [Accepted: 04/19/2005] [Indexed: 11/16/2022]
Abstract
Proline-rich tyrosine kinase 2 (Pyk2) is activated in neurones following NMDA receptor stimulation via PKC. Pyk2 is involved in hippocampal LTP and acts to potentiate NMDA receptor function. Elevations of intracellular Ca2+ and cAMP levels are key NMDA receptor-dependent triggering events leading to induction of hippocampal LTP. In this study, we compared the ability of A23187 (Ca2+ ionophore) or forskolin (adenylate cyclase activator) to modulate the phosphorylation of Pyk2 in rat hippocampal slices. Using an immunoprecipitation assay, phosphorylated Pyk2 levels were increased following treatment with A23187, levels peaking at around 10 min. Staurosporine, at concentrations inhibiting conventional and novel isoforms of PKC, and chelerythrine, at concentrations inhibiting the atypical PKC isoform PKMxi, were compared for their ability to attenuate the effect of A23187. Exposure of acute hippocampal slices to either chelerythrine or staurosporine completely blocked enhanced phosphorylation of Pyk2 by A23187, suggesting a possible involvement of PKMxi and typical PKCs in Pyk2 activation by Ca2+. In contrast, application of forskolin reduced phosphorylated Pyk2 below basal levels, suggesting that cAMP inhibits Pyk2. These results implicate Ca2+ and multiple forms of PKC in the activation of Pyk2 downstream of NMDA receptors and suggest that cAMP-dependent processes exert a suppressive action on Pyk2.
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Affiliation(s)
- K A Alier
- Division of Neuroscience and Biomedical Systems, Institute of Biomedical and Life Sciences, West Medical Building, University of Glasgow, Glasgow G12 8QQ, Scotland, UK.
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Tumbarello DA, Brown MC, Hetey SE, Turner CE. Regulation of paxillin family members during epithelial-mesenchymal transformation: a putative role for paxillin delta. J Cell Sci 2006; 118:4849-63. [PMID: 16219691 DOI: 10.1242/jcs.02615] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Epithelial-mesenchymal transformation (EMT) and the resulting induction of cell motility are essential components of tissue remodeling during embryonic development and wound repair, as well as tumor progression to an invasive metastatic phenotype. Paxillin, a multi-domain adaptor and phosphoprotein has previously been implicated in integrin signaling and cell motility. In this report we characterize a novel paxillin gene product, paxillin delta, generated from an evolutionarily conserved internal translation initiation site within the full-length paxillin mRNA. Paxillin delta, which lacks the key phosphorylation sites Y31 and Y118 as well as the ILK and actopaxin binding LD1 motif, exhibits a restricted distribution to epithelial cell types and is downregulated during TGF-beta1-induced EMT of normal murine mammary gland (NMuMG) epithelial cells. Interestingly, Hic-5, a paxillin superfamily member, exhibits a reciprocal protein expression profile to paxillin delta. In addition, paxillin delta expression is maintained following NMuMG differentiation in a 3D collagen I gel while other focal adhesion components are downregulated. Paxillin delta protein expression coincided with reduced paxillin tyrosine phosphorylation in NMuMG cells and paxillin delta overexpression in CHO.K1 cells inhibited adhesion-mediated tyrosine phosphorylation of paxillin. Forced expression of paxillin delta in NMuMG cells suppressed cell migration whereas Hic-5 overexpression stimulated motility. Together our data support a role for paxillin delta as a naturally occurring functional antagonist of paxillin signaling potentially through suppression of a Crk-mediated pathway during processes associated with cell migration.
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Affiliation(s)
- David A Tumbarello
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, 750 East Adams Street, Syracuse, NY 13210, USA
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Arcucci A, Montagnani S, Gionti E. Expression and intracellular localization of Pyk2 in normal and v-src transformed chicken epiphyseal chondrocytes. Biochimie 2005; 88:77-84. [PMID: 16040187 DOI: 10.1016/j.biochi.2005.06.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2005] [Accepted: 06/20/2005] [Indexed: 11/24/2022]
Abstract
The expression and localization of prolin-rich tyrosine kinase 2 (Pyk2) were studied in chick embryo epiphyseal chondrocytes. Two immunoreactive bands were detected in chondrocytes, a major band with an apparent Mr of 123 kDa and a minor band with an apparent Mr of 68 kDa. The major band appears to migrate as a doublet with apparent Mr of 116/123 kDa. Increased levels of the three forms of Pyk2 were observed in v-src transformed chondrocytes as compared to control uninfected chondrocytes. Immunofluorescent staining shows that Pyk2 is clearly visible in the cytosol and in the perinuclear region of control and v-src-chondrocytes and displays a pattern very similar to the distribution of the mitochondrial marker Mito Tracker. More, immunofluorescent staining shows that Pyk2 is nuclear in most chondrocytes. By subcellular fractionation, the p116/123 Pyk2 doublet, was found to be accumulated mainly in the cytoplasm while the p68 Pyk2 form, was found to be accumulated exclusively in the nucleus. The differential nuclear/cytoplasmic distribution of the Pyk2 forms remains unchanged after v-Src-induced transformation. The p68 Pyk2 form could no longer be detected by using a N-terminus domain-specific anti-Pyk2 antibody. Consistently, Pyk2 immunoreactivity was restricted to the cytoplasm of control and v-src transformed chondrocytes. Thus it appears that the p68 Pyk2 form that accumulates in the nucleus has a deletion in the N-terminus region.
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Affiliation(s)
- Alessandro Arcucci
- Dipartimento di Scienze Biomorfologiche e Funzionali, Università di Napoli Federico II, via S. Pansini n. 5, 80131 Napoli, Italy
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García MG, Toney SJ, Hille MB. Focal adhesion kinase (FAK) expression and phosphorylation in sea urchin embryos. Gene Expr Patterns 2004; 4:223-34. [PMID: 15161103 DOI: 10.1016/j.modgep.2003.08.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2003] [Revised: 08/13/2003] [Accepted: 08/19/2003] [Indexed: 11/20/2022]
Abstract
We have cloned three cDNA isoforms of focal adhesion kinase (FAK) from the sea urchin, Lytechinus variegatus. The sea urchin FAK is more closely related to FAK from other deuterostomes than from invertebrate protostomes or to cell adhesion kinase beta (CAKbeta/Pyk2/FAK2). FAK is expressed in all cells of sea urchin embryos by the 120-cell stage and strongly in blastulae. Phospho-FAK concentrates on basal surfaces of epithelial cells in early blastulae and occurs in syncytial cables of primary mesenchyme cells (PMC). Inhibition of FAK by constructs of FAK-related non-kinase delays blastocoel expansion and early PMC ingression. These results suggest that FAK has roles in cell adhesion and in the shape and integrity of the epithelial cells in sea urchin embryos.
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Affiliation(s)
- María Guadalupe García
- Department of Biology, University of Washington, Box 351800, Seattle, WA 98195-1800, USA
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Meyer AN, Gastwirt RF, Schlaepfer DD, Donoghue DJ. The Cytoplasmic Tyrosine Kinase Pyk2 as a Novel Effector of Fibroblast Growth Factor Receptor 3 Activation. J Biol Chem 2004; 279:28450-7. [PMID: 15105428 DOI: 10.1074/jbc.m403335200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Activating mutations within fibroblast growth factor receptor 3 (FGFR3), a receptor tyrosine kinase, are responsible for human skeletal dysplasias including achondroplasia and the neonatal lethal syndromes thanatophoric dysplasia types I and II. Several of these same FGFR3 mutations have also been identified somatically in human cancers, including multiple myeloma, bladder carcinoma, and cervical cancer. The molecular pathways exploited by FGFR3 to stimulate abnormal proliferation during neoplasia are unclear. The nonreceptor protein-tyrosine kinase Pyk2 (proline-rich tyrosine kinase 2) has been shown previously to regulate apoptosis in multiple myeloma cells. Here we describe a novel interaction between FGFR3 and Pyk2, mediated by the juxtamembrane domain of FGFR3 and the kinase domain of Pyk2. Within the FGFR family, Pyk2 also interacted significantly with FGFR2. Overexpression of Pyk2 alone led to its spontaneous activation and tyrosine phosphorylation, resulting in activation of Stat5B, indicated by the reporter GFP-Stat5B. These effects were completely dependent upon Tyr(402), the autophosphorylation site of Pyk2, which allows recruitment of Src family members for further activating phosphorylations at other sites on Pyk2. In the presence of activated FGFR3, the activation of Pyk2 itself became independent of Tyr(402), indicating that FGFR3 activation circumvents the requirement for c-Src recruitment at Tyr(402) of Pyk2. We also examined the role of the tyrosine phosphatase Shp2 in antagonizing Pyk2 activation. Taken together, these results suggest that signaling pathways regulated by FGFR3 may converge with Pyk2-dependent pathways to provide maximal activation of Stat5B.
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Affiliation(s)
- April N Meyer
- Department of Chemistry and Biochemistry, Center for Molecular Genetics, University of California-San Diego, La Jolla, CA 92093-0367, USA
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Champagne C, Landry MC, Gingras MC, Lavoie JN. Activation of Adenovirus Type 2 Early Region 4 ORF4 Cytoplasmic Death Function by Direct Binding to Src Kinase Domain. J Biol Chem 2004; 279:25905-15. [PMID: 15070897 DOI: 10.1074/jbc.m400933200] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Adenovirus type 2 (Ad2) early region 4 ORF4 (E4orf4) triggers a major death pathway that requires its accumulation in cellular membranes and its tyrosine phosphorylation. This program is regulated by Src family kinases and triggers a potent ZVAD (benzyloxycarbonyl-VAD)- and Bcl2-resistant cell death response in human-transformed cells. How E4orf4 deregulates Src-dependent signaling is unknown. Here we provide strong evidence that a physical interaction requiring the kinase domain of Src and the arginine-rich motif of E4orf4 is involved. The Src binding domain of E4orf4 overlaps with, but is distinct from that of the Balpha subunit of protein phosphatase 2A (PP2A-Balpha) and some E4orf4 complexes contain both PP2A and Src. Functional assays using mutant E4orf4 revealed that deregulation of Src signaling, activation of the Jun kinase pathway, and cell blebbing were all critically dependent on Src binding. In contrast, PP2A-Balpha binding per se was not required to engage the Src-dependent death pathway but was more critical for triggering a distinct death activity. Both E4orf4 death activities were manifested within a given cell population, were typified by distinct morphological features, and contributed to overall cell killing, although to different extents in various cell types. We conclude that E4orf4 binding to the Src kinase domain leads to deregulation of Src signaling and plays a crucial role in induction of the cytoplasmic death pathway. Nonetheless, both Src and PP2A enzymes are critical targets of E4orf4 that likely cooperate to trigger E4orf4-induced tumor cell killing and whose relative contributions may vary in function of the cellular background.
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Affiliation(s)
- Claudia Champagne
- Centre de Recherche en Cancérologie de l'Université Laval, L'Hôtel-Dieu de Québec, CHUQ, Québec G1R 2J6, Canada
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Dylla SJ, Deyle DR, Theunissen K, Padurean AM, Verfaillie CM. Integrin engagement-induced inhibition of human myelopoiesis is mediated by proline-rich tyrosine kinase 2 gene products. Exp Hematol 2004; 32:365-74. [PMID: 15050747 DOI: 10.1016/j.exphem.2004.01.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2003] [Revised: 01/13/2004] [Accepted: 01/16/2004] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Hematopoietic progenitor proliferation and differentiation are inhibited by integrin engagement of fibronectin (FN). Focal adhesion kinases have been shown to mediate intracellular signaling from integrins, and we recently demonstrated that gene expression and pre-mRNA splicing of the focal adhesion kinase, PYK2, is abnormal in CD34(+) cells from chronic myelogenous leukemia (CML) patients. Here we investigated whether PYK2 gene products mediate integrin signaling in hematopoietic stem and progenitor cells. METHODS Cord blood CD34(+) cells were retrovirally transduced with vectors encoding Pyk2H, Pyk2, or the dominant negative-acting, kinase-deficient, C-terminal PYK2 fragment, PRNK, and myeloid proliferation and differentiation was assessed using colony-forming cell (CFC), long-term culture-initiating cell (LTC-IC), and liquid culture assays. RESULTS CD34(+) cells overexpressing Pyk2H or Pyk2 generated 50% less colony-forming unit granulocyte/macrophage (CFU-GM) than eGFP-transduced controls. Although the number of CFC generated by PRNK-expressing cells was unchanged, LTC-IC were significantly reduced. Culture of CD34(+) cells on FN significantly reduced the generation of mature myeloid cells vs those cultured on BSA-coated wells, and could be overcome by addition of SCF. As is observed when integrins are engaged, overexpression of either Pyk2H or Pyk2 decreased committed myeloid progenitor proliferation and differentiation; however, SCF could not override this inhibition. Finally, as is observed when integrins are not engaged, PRNK-mediated inhibition of endogenous Pyk2H resulted in integrin-nonresponsive proliferation and differentiation of myeloid precursors and accelerated differentiation of primitive hematopoietic progenitors. CONCLUSION These studies indicate that PYK2 gene products mediate integrin-induced signals that regulate myelopoiesis.
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Affiliation(s)
- Scott J Dylla
- Stem Cell Institute and Department of Medicine, University of Minnesota, Minneapolis, Minn, USA
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Salesse S, Dylla SJ, Verfaillie CM. p210BCR/ABL-induced alteration of pre-mRNA splicing in primary human CD34+ hematopoietic progenitor cells. Leukemia 2004; 18:727-33. [PMID: 14961028 DOI: 10.1038/sj.leu.2403310] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Chronic myelogenous leukemia (CML) is a malignancy of the human hematopoietic stem cell (HSC) caused by the p210BCR/ABL oncoprotein. Although alternative splicing of pre-mRNA is a critical determinant of a cell's protein repertoire, it has not been associated with CML pathogenesis. We identified a BCR/ABL-dependent increase in expression of multiple genes involved in pre-mRNA splicing (eg SRPK1, RNA Helicase II/Gu, and hnRNPA2/B1) by subtractive hybridization of cDNA from p210BCR/ABL-eGFP vs eGFP-transduced umbilical cord blood CD34+ cells. beta1-integrin signaling is important to HSC maintenance and proliferation/differentiation, and is abnormal in CML. As an example of how changes in pre-mRNA processing might contribute to CML pathogenesis, we observed alternative splicing of a gene for a beta1-integrin-responsive nonreceptor tyrosine kinase (PYK2), resulting in increased expression of full-length Pyk2 in BCR/ABL-containing cells. Treatment of p210BCR/ABL-positive cells with the Abl-specific tyrosine kinase inhibitor STI571 reverted PYK2 splicing to a configuration more consistent with normal cells, and correlated with decreased expression of BCR/ABL-induced proteins involved in pre-mRNA processing. Whether altered PYK2 splicing contributes to CML pathogenesis remains undetermined; however, we propose that generic changes in pre-mRNA splicing as a result of p210BCR/ABL kinase activity may contribute to CML pathogenesis.
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MESH Headings
- Antigens, CD34
- Focal Adhesion Kinase 2
- Fusion Proteins, bcr-abl/physiology
- Hematopoietic Stem Cells/metabolism
- Hematopoietic Stem Cells/pathology
- Humans
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/etiology
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology
- Leukemia, Myeloid, Chronic-Phase/etiology
- Leukemia, Myeloid, Chronic-Phase/genetics
- Leukemia, Myeloid, Chronic-Phase/pathology
- Neoplastic Stem Cells/metabolism
- Neoplastic Stem Cells/pathology
- Protein-Tyrosine Kinases/genetics
- RNA Precursors/genetics
- RNA Splicing
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Affiliation(s)
- S Salesse
- Stem Cell Institute, University of Minnesota, Minneapolis, MN 55455, USA
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Sheehan TP, Neve RL, Duman RS, Russell DS. Antidepressant effect of the calcium-activated tyrosine kinase Pyk2 in the lateral septum. Biol Psychiatry 2003; 54:540-51. [PMID: 12946883 DOI: 10.1016/s0006-3223(02)01815-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Accumulating evidence indicates that neural activity in the lateral septum (LS) influences the pathophysiology of depression and therapeutic effectiveness of antidepressant drugs. For example, the development of behavioral deficits in animal screens for antidepressant drug activity corresponds with a blunting of LS activity, whereas chronic treatment with antidepressants enhances cell firing in the LS; however, the molecular mechanisms underlying such behavioral functions of the LS have not been determined. The nonreceptor tyrosine kinase Pyk2 is highly expressed in the LS and plays important roles in regulating cellular excitability and synaptic plasticity, making it an attractive candidate for regulating the effects of stress and antidepressants on LS functioning and behavior. We provide evidence that stress decreases Pyk2 phosphorylation in the LS, whereas enhancing Pyk2 expression in LS neurons has an antidepressant effect behaviorally.Pyk2 messenger ribonucleic acid (mRNA) expression in the rat forebrain was detected by in situ hybridization, and a brief description of the distribution of Pyk2 mRNA in selected areas is presented. Levels of total Pyk2 protein and phosphorylated Pyk2 were subsequently measured in the LS and hippocampus following stress exposure, as were levels of extracellular stimuli-regulated kinase (Erk) and phospho-Erk. Herpes simplex virus (HSV)-mediated gene transfer was then used to enhance Pyk2 expression in the LS, and the effect this had on behavior in the learned helplessness model of depression was evaluated. High levels of Pyk2 mRNA were detected in a number of forebrain regions, including the hippocampus and LS. Following acute stress exposure, subjects showed a decrease in phosphorylated Pyk2 and Erk in the LS but not in the hippocampus. Total levels of Pyk2 and Erk remained unchanged following stress. In the learned helplessness paradigm, injection of HSV-Pyk2 into the LS prevented the active avoidance deficit caused by exposure to inescapable shock, indicative of an antidepressant effect. These results indicate that following acute stress, Pyk2 and Erk activity in the LS are decreased, whereas experimentally increasing Pyk2 activity in LS neurons reverses the behavioral deficits of acute, inescapable stress. These findings establish a role for the tyrosine kinase Pyk2 in the biochemical and behavioral responses to stress and suggest a possible role in the pathophysiology of depression, particularly notable considering Pyk2's role in promoting synaptic plasticity.
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Affiliation(s)
- Teige P Sheehan
- Department of Psychiatry, Division of Molecular Psychiatry, Yale University School of Medicine, Connecticut Mental Health Center, New Haven, Connecticut 06508, USA
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de Chaldée M, Gaillard MC, Bizat N, Buhler JM, Manzoni O, Bockaert J, Hantraye P, Brouillet E, Elalouf JM. Quantitative assessment of transcriptome differences between brain territories. Genome Res 2003; 13:1646-53. [PMID: 12840043 PMCID: PMC403738 DOI: 10.1101/gr.1173403] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Transcriptome analysis of mammalian brain structures is a potentially powerful approach in addressing the diversity of cerebral functions. Here, we used a microassay for serial analysis of gene expression (SAGE) to generate quantitative mRNA expression profiles of normal adult mouse striatum, nucleus accumbens, and somatosensory cortex. Comparison of these profiles revealed 135 transcripts heterogeneously distributed in the brain. Among them, a majority (78), although matching a registered sequence, are novel regional markers. To improve the anatomical resolution of our analysis, we performed in situ hybridization and observed unique expression patterns in discrete brain regions for a number of candidates. We assessed the distribution of the new markers in peripheral tissues using quantitative RT-PCR, Northern hybridization, and published SAGE data. In most cases, expression was higher in the brain than in peripheral tissues. Because the markers were selected according to their expression level, without reference to prior knowledge, our studies provide an unbiased, comprehensive molecular signature for various mammalian brain structures that can be used to investigate their plasticity under a variety of circumstances.
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Affiliation(s)
- Michel de Chaldée
- Service de Biochimie et de Génétique Moléculaire, Département de Biologie Joliot-Curie, Commissariat à l'Energie Atomique (CEA) Saclay, 91191 Gif-sur-Yvette Cedex, France
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Abstract
Tyrosine kinases are key regulators of breast cancer cell survival and proliferation. Ten years ago, we conducted a screen for protein kinases expressed in primary human breast tumors and cultured cancer cells. Here, we review the progress from the last ten years in understanding the functions of these kinases with a focus on breast cancer. Three themes emerge: (1). tyrosine kinases regulate proliferation through the MAP Kinase pathway, (2). tyrosine kinases regulate cellular survival through the PI3 Kinase-Akt pathway, and (3). the cell cycle is regulated through a complex series of serine-threonine kinases. Our improved understanding of these signaling cascades has led to novel strategies for therapeutic intervention in breast cancer.
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Affiliation(s)
- Rolf J Craven
- Department of Surgery, University of North Carolina at Chapel Hill, 21-237 Lineberger, Comprehensive Cancer Centre, Camous Box 7295, Chapel Hill, NC 27599, USA.
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