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Górska A, Mazur AJ. Integrin-linked kinase (ILK): the known vs. the unknown and perspectives. Cell Mol Life Sci 2022; 79:100. [PMID: 35089438 PMCID: PMC8799556 DOI: 10.1007/s00018-021-04104-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 11/29/2021] [Accepted: 12/17/2021] [Indexed: 02/08/2023]
Abstract
Integrin-linked kinase (ILK) is a multifunctional molecular actor in cell-matrix interactions, cell adhesion, and anchorage-dependent cell growth. It combines functions of a signal transductor and a scaffold protein through its interaction with integrins, then facilitating further protein recruitment within the ILK-PINCH-Parvin complex. ILK is involved in crucial cellular processes including proliferation, survival, differentiation, migration, invasion, and angiogenesis, which reflects on systemic changes in the kidney, heart, muscle, skin, and vascular system, also during the embryonal development. Dysfunction of ILK underlies the pathogenesis of various diseases, including the pro-oncogenic activity in tumorigenesis. ILK localizes mostly to the cell membrane and remains an important component of focal adhesion. We do know much about ILK but a lot still remains either uncovered or unclear. Although it was initially classified as a serine/threonine-protein kinase, its catalytical activity is now questioned due to structural and functional issues, leaving the exact molecular mechanism of signal transduction by ILK unsolved. While it is known that the three isoforms of ILK vary in length, the presence of crucial domains, and modification sites, most of the research tends to focus on the main isoform of this protein while the issue of functional differences of ILK2 and ILK3 still awaits clarification. The activity of ILK is regulated on the transcriptional, protein, and post-transcriptional levels. The crucial role of phosphorylation and ubiquitylation has been investigated, but the functions of the vast majority of modifications are still unknown. In the light of all those open issues, here we present an extensive literature survey covering a wide spectrum of latest findings as well as a past-to-present view on controversies regarding ILK, finishing with pointing out some open questions to be resolved by further research.
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Affiliation(s)
- Agata Górska
- Department of Cell Pathology, Faculty of Biotechnology, University of Wroclaw, ul. Joliot-Curie 14a, 50-383, Wrocław, Poland.
| | - Antonina Joanna Mazur
- Department of Cell Pathology, Faculty of Biotechnology, University of Wroclaw, ul. Joliot-Curie 14a, 50-383, Wrocław, Poland.
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2
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González Wusener AE, González Á, Perez Collado ME, Maza MR, General IJ, Arregui CO. Protein tyrosine phosphatase 1B targets focal adhesion kinase and paxillin in cell-matrix adhesions. J Cell Sci 2021; 134:272564. [PMID: 34553765 DOI: 10.1242/jcs.258769] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 09/14/2021] [Indexed: 11/20/2022] Open
Abstract
Protein tyrosine phosphatase 1B (PTP1B, also known as PTPN1) is an established regulator of cell-matrix adhesion and motility. However, the nature of substrate targets at adhesion sites remains to be validated. Here, we used bimolecular fluorescence complementation assays, in combination with a substrate trapping mutant of PTP1B, to directly examine whether relevant phosphotyrosines on paxillin and focal adhesion kinase (FAK, also known as PTK2) are substrates of the phosphatase in the context of cell-matrix adhesion sites. We found that the formation of catalytic complexes at cell-matrix adhesions requires intact tyrosine residues Y31 and Y118 on paxillin, and the localization of FAK at adhesion sites. Additionally, we found that PTP1B specifically targets Y925 on the focal adhesion targeting (FAT) domain of FAK at adhesion sites. Electrostatic analysis indicated that dephosphorylation of this residue promotes the closed conformation of the FAT 4-helix bundle and its interaction with paxillin at adhesion sites.
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Affiliation(s)
- Ana E González Wusener
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Martín, Buenos Aires 1650, Argentina
| | - Ángela González
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Martín, Buenos Aires 1650, Argentina
| | - María E Perez Collado
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Martín, Buenos Aires 1650, Argentina
| | - Melina R Maza
- Escuela de Ciencia y Tecnología, Universidad Nacional de San Martin, Instituto de Ciencias Físicas and CONICET, San Martin, Buenos Aires 1650, Argentina
| | - Ignacio J General
- Escuela de Ciencia y Tecnología, Universidad Nacional de San Martin, Instituto de Ciencias Físicas and CONICET, San Martin, Buenos Aires 1650, Argentina
| | - Carlos O Arregui
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Martín, Buenos Aires 1650, Argentina
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3
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Roles of Endocytic Processes and Early Endosomes on Focal Adhesion Dynamics in MDA-MB-231 Cells. Rep Biochem Mol Biol 2021; 10:145-155. [PMID: 34604404 DOI: 10.52547/rbmb.10.2.145] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 04/22/2021] [Indexed: 01/02/2023]
Abstract
Background Focal adhesion (FA) play a critical role in many biological processes which include cell survival and cell migration. They serve as cellular anchor, allowing cells to stay attached to the extracellular matrix (ECM), and can also regulate cellular transduction. Previously, it has been suggested that vesicles such as endosomes could interact directly with FA or be implicated in their turnover. In this study, we investigated whether there is a relationship between FA and the early endocytic machinery in MDA-MB-231 cells. Methods In this study, cell culture, transfection, time laps confocal microscopies, immunocytochemistry, western blotting, Cell fractionation and immunoprecipitation techniques were performed. Results Cells acutely treated with Dynasore, an inhibitor of dynamin, or with Pitstop 2, an inhibitor of clathryn-dependent endocytosis showed a reduction in the expression of early endosome biomarkers such as Rab5 and EEA1. Additionally, cells treated with these endocytic inhibitors exhibited an increase number and size of FA, as well as an increase FA turnover duration. This data was consistent with the reduction of the speed of cell migration. We demonstrated that Rab5- and EEA1-positive early endosomes were found to be colocalized with internalized FA. Conclusion The present study suggests that there is a link between FA and early endosome markers, which indicates that the early endosomes may be involved in FA dynamics.
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Alpha KM, Xu W, Turner CE. Paxillin family of focal adhesion adaptor proteins and regulation of cancer cell invasion. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2020; 355:1-52. [PMID: 32859368 PMCID: PMC7737098 DOI: 10.1016/bs.ircmb.2020.05.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The paxillin family of proteins, including paxillin, Hic-5, and leupaxin, are focal adhesion adaptor/scaffolding proteins which localize to cell-matrix adhesions and are important in cell adhesion and migration of both normal and cancer cells. Historically, the role of these proteins in regulating the actin cytoskeleton through focal adhesion-mediated signaling has been well documented. However, studies in recent years have revealed additional functions in modulating the microtubule and intermediate filament cytoskeletons to affect diverse processes including cell polarization, vesicle trafficking and mechanosignaling. Expression of paxillin family proteins in stromal cells is also important in regulating tumor cell migration and invasion through non-cell autonomous effects on the extracellular matrix. Both paxillin and Hic-5 can also influence gene expression through a variety of mechanisms, while their own expression is frequently dysregulated in various cancers. Accordingly, these proteins may serve as valuable targets for novel diagnostic and treatment approaches in cancer.
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Affiliation(s)
- Kyle M Alpha
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, Syracuse, NY, United States
| | - Weiyi Xu
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, Syracuse, NY, United States
| | - Christopher E Turner
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, Syracuse, NY, United States.
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5
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Abu-Thuraia A, Goyette MA, Boulais J, Delliaux C, Apcher C, Schott C, Chidiac R, Bagci H, Thibault MP, Davidson D, Ferron M, Veillette A, Daly RJ, Gingras AC, Gratton JP, Côté JF. AXL confers cell migration and invasion by hijacking a PEAK1-regulated focal adhesion protein network. Nat Commun 2020; 11:3586. [PMID: 32681075 PMCID: PMC7368075 DOI: 10.1038/s41467-020-17415-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 06/28/2020] [Indexed: 01/08/2023] Open
Abstract
Aberrant expression of receptor tyrosine kinase AXL is linked to metastasis. AXL can be activated by its ligand GAS6 or by other kinases, but the signaling pathways conferring its metastatic activity are unknown. Here, we define the AXL-regulated phosphoproteome in breast cancer cells. We reveal that AXL stimulates the phosphorylation of a network of focal adhesion (FA) proteins, culminating in faster FA disassembly. Mechanistically, AXL phosphorylates NEDD9, leading to its binding to CRKII which in turn associates with and orchestrates the phosphorylation of the pseudo-kinase PEAK1. We find that PEAK1 is in complex with the tyrosine kinase CSK to mediate the phosphorylation of PAXILLIN. Uncoupling of PEAK1 from AXL signaling decreases metastasis in vivo, but not tumor growth. Our results uncover a contribution of AXL signaling to FA dynamics, reveal a long sought-after mechanism underlying AXL metastatic activity, and identify PEAK1 as a therapeutic target in AXL positive tumors. AXL receptor tyrosine kinase has a role in metastasis but the mechanism is unclear. In this study, the authors show that AXL activation can control focal adhesion dynamics via PEAK1 and that AXL-mediated PEAK1 phosphorylation is required for metastasis of triple negative breast cancer cells in vivo.
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Affiliation(s)
- Afnan Abu-Thuraia
- Montreal Clinical Research Institute (IRCM), Montréal, QC, H2W 1R7, Canada.,Molecular Biology Programs, Université de Montréal, Montréal, QC, H3T 1J4, Canada
| | - Marie-Anne Goyette
- Montreal Clinical Research Institute (IRCM), Montréal, QC, H2W 1R7, Canada.,Molecular Biology Programs, Université de Montréal, Montréal, QC, H3T 1J4, Canada
| | - Jonathan Boulais
- Montreal Clinical Research Institute (IRCM), Montréal, QC, H2W 1R7, Canada
| | - Carine Delliaux
- Montreal Clinical Research Institute (IRCM), Montréal, QC, H2W 1R7, Canada
| | - Chloé Apcher
- Montreal Clinical Research Institute (IRCM), Montréal, QC, H2W 1R7, Canada.,Molecular Biology Programs, Université de Montréal, Montréal, QC, H3T 1J4, Canada
| | - Céline Schott
- Montreal Clinical Research Institute (IRCM), Montréal, QC, H2W 1R7, Canada.,Molecular Biology Programs, Université de Montréal, Montréal, QC, H3T 1J4, Canada
| | - Rony Chidiac
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, QC, H3C 3J7, Canada
| | - Halil Bagci
- Montreal Clinical Research Institute (IRCM), Montréal, QC, H2W 1R7, Canada.,Department of Anatomy and Cell Biology, McGill University, Montréal, QC, H3A 0C7, Canada.,Institute of Biochemistry, ETH Zürich, Otto-Stern-Weg 3, 8093, Zürich, Switzerland
| | | | - Dominique Davidson
- Montreal Clinical Research Institute (IRCM), Montréal, QC, H2W 1R7, Canada
| | - Mathieu Ferron
- Montreal Clinical Research Institute (IRCM), Montréal, QC, H2W 1R7, Canada.,Molecular Biology Programs, Université de Montréal, Montréal, QC, H3T 1J4, Canada.,Division of Experimental Medicine, McGill University, Montréal, QC, H4A 3J1, Canada
| | - André Veillette
- Montreal Clinical Research Institute (IRCM), Montréal, QC, H2W 1R7, Canada.,Molecular Biology Programs, Université de Montréal, Montréal, QC, H3T 1J4, Canada
| | - Roger J Daly
- Cancer Program, Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, 3800, Australia
| | - Anne-Claude Gingras
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON, M5G 1X5, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Jean-Philippe Gratton
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, QC, H3C 3J7, Canada
| | - Jean-François Côté
- Montreal Clinical Research Institute (IRCM), Montréal, QC, H2W 1R7, Canada. .,Molecular Biology Programs, Université de Montréal, Montréal, QC, H3T 1J4, Canada. .,Department of Anatomy and Cell Biology, McGill University, Montréal, QC, H3A 0C7, Canada. .,Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, QC, H3C 3J7, Canada.
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6
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Maziveyi M, Alahari SK. Cell matrix adhesions in cancer: The proteins that form the glue. Oncotarget 2018; 8:48471-48487. [PMID: 28476046 PMCID: PMC5564663 DOI: 10.18632/oncotarget.17265] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 03/27/2017] [Indexed: 12/28/2022] Open
Abstract
The main purposes of Integrin-mediated cell contacts are to interpret bi-directional signals between the extracellular environment and intracellular proteins, as well as, anchor the cell to a matrix. Many cell adhesion molecules have been discovered with a wide spectrum of responsibilities, including recruiting, activating, elongating, and maintaining. This review will perlustrate some of the key incidences that precede focal adhesion formation. Tyrosine phosphorylation is a key signaling initiation event that leads to the recruitment of multiple proteins to focal adhesion sites. Recruitment and concentration of proteins such as Paxillin and Vinculin to Integrin clutches is necessary for focal adhesion development. The assembled networks are responsible for transmitting signals back and forth from the extracellular matrix (ECM) to Actin and its binding proteins. Cancer cells exhibit highly altered focal adhesion dynamics. This review will highlight some key discoveries in cancer cell adhesion, as well as, identify current gaps in knowledge.
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Affiliation(s)
- Mazvita Maziveyi
- Department of Biochemistry and Molecular Biology, Stanley S. Scott Cancer Center, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - Suresh K Alahari
- Department of Biochemistry and Molecular Biology, Stanley S. Scott Cancer Center, Louisiana State University Health Sciences Center, New Orleans, LA, USA
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7
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Duran CL, Howell DW, Dave JM, Smith RL, Torrie ME, Essner JJ, Bayless KJ. Molecular Regulation of Sprouting Angiogenesis. Compr Physiol 2017; 8:153-235. [PMID: 29357127 DOI: 10.1002/cphy.c160048] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The term angiogenesis arose in the 18th century. Several studies over the next 100 years laid the groundwork for initial studies performed by the Folkman laboratory, which were at first met with some opposition. Once overcome, the angiogenesis field has flourished due to studies on tumor angiogenesis and various developmental models that can be genetically manipulated, including mice and zebrafish. In addition, new discoveries have been aided by the ability to isolate primary endothelial cells, which has allowed dissection of various steps within angiogenesis. This review will summarize the molecular events that control angiogenesis downstream of biochemical factors such as growth factors, cytokines, chemokines, hypoxia-inducible factors (HIFs), and lipids. These and other stimuli have been linked to regulation of junctional molecules and cell surface receptors. In addition, the contribution of cytoskeletal elements and regulatory proteins has revealed an intricate role for mobilization of actin, microtubules, and intermediate filaments in response to cues that activate the endothelium. Activating stimuli also affect various focal adhesion proteins, scaffold proteins, intracellular kinases, and second messengers. Finally, metalloproteinases, which facilitate matrix degradation and the formation of new blood vessels, are discussed, along with our knowledge of crosstalk between the various subclasses of these molecules throughout the text. Compr Physiol 8:153-235, 2018.
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Affiliation(s)
- Camille L Duran
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, USA
| | - David W Howell
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, USA
| | - Jui M Dave
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, USA
| | - Rebecca L Smith
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, USA
| | - Melanie E Torrie
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, USA
| | - Jeffrey J Essner
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, USA
| | - Kayla J Bayless
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, USA
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8
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Goicoechea SM, Zinn A, Awadia SS, Snyder K, Garcia-Mata R. A RhoG-mediated signaling pathway that modulates invadopodia dynamics in breast cancer cells. J Cell Sci 2017; 130:1064-1077. [PMID: 28202690 DOI: 10.1242/jcs.195552] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 01/14/2017] [Indexed: 01/11/2023] Open
Abstract
One of the hallmarks of cancer is the ability of tumor cells to invade surrounding tissues and metastasize. During metastasis, cancer cells degrade the extracellular matrix, which acts as a physical barrier, by developing specialized actin-rich membrane protrusion structures called invadopodia. The formation of invadopodia is regulated by Rho GTPases, a family of proteins that regulates the actin cytoskeleton. Here, we describe a novel role for RhoG in the regulation of invadopodia disassembly in human breast cancer cells. Our results show that RhoG and Rac1 have independent and opposite roles in the regulation of invadopodia dynamics. We also show that SGEF (also known as ARHGEF26) is the exchange factor responsible for the activation of RhoG during invadopodia disassembly. When the expression of either RhoG or SGEF is silenced, invadopodia are more stable and have a longer lifetime than in control cells. Our findings also demonstrate that RhoG and SGEF modulate the phosphorylation of paxillin, which plays a key role during invadopodia disassembly. In summary, we have identified a novel signaling pathway involving SGEF, RhoG and paxillin phosphorylation, which functions in the regulation of invadopodia disassembly in breast cancer cells.
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Affiliation(s)
- Silvia M Goicoechea
- Department of Biological Sciences, University of Toledo, Toledo, OH 43606, USA
| | - Ashtyn Zinn
- Department of Biological Sciences, University of Toledo, Toledo, OH 43606, USA
| | - Sahezeel S Awadia
- Department of Biological Sciences, University of Toledo, Toledo, OH 43606, USA
| | - Kyle Snyder
- Department of Biological Sciences, University of Toledo, Toledo, OH 43606, USA
| | - Rafael Garcia-Mata
- Department of Biological Sciences, University of Toledo, Toledo, OH 43606, USA
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9
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Dong JM, Tay FPL, Swa HLF, Gunaratne J, Leung T, Burke B, Manser E. Proximity biotinylation provides insight into the molecular composition of focal adhesions at the nanometer scale. Sci Signal 2016; 9:rs4. [PMID: 27303058 DOI: 10.1126/scisignal.aaf3572] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Focal adhesions are protein complexes that link metazoan cells to the extracellular matrix through the integrin family of transmembrane proteins. Integrins recruit many proteins to these complexes, referred to as the "adhesome." We used proximity-dependent biotinylation (BioID) in U2OS osteosarcoma cells to label proteins within 15 to 25 nm of paxillin, a cytoplasmic focal adhesion protein, and kindlin-2, which directly binds β integrins. Using mass spectrometry analysis of the biotinylated proteins, we identified 27 known adhesome proteins and 8 previously unknown components close to paxillin. However, only seven of these proteins interacted directly with paxillin, one of which was the adaptor protein Kank2. The proteins in proximity to β integrin included 15 of the adhesion proteins identified in the paxillin BioID data set. BioID also correctly established kindlin-2 as a cell-cell junction protein. By focusing on this smaller data set, new partners for kindlin-2 were found, namely, the endocytosis-promoting proteins liprin β1 and EFR3A, but, contrary to previous reports, not the filamin-binding protein migfilin. A model adhesome based on both data sets suggests that focal adhesions contain fewer components than previously suspected and that paxillin lies away from the plasma membrane. These data not only illustrate the power of using BioID and stable isotope-labeled mass spectrometry to define macromolecular complexes but also enable the correct identification of therapeutic targets within the adhesome.
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Affiliation(s)
- Jing-Ming Dong
- sGSK Group, Institute of Molecular and Cell Biology, Agency for Science Technology and Research, Proteos Building, 61 Biopolis Drive, Singapore 138673, Singapore
| | - Felicia Pei-Ling Tay
- sGSK Group, Institute of Molecular and Cell Biology, Agency for Science Technology and Research, Proteos Building, 61 Biopolis Drive, Singapore 138673, Singapore
| | - Hannah Lee-Foon Swa
- Quantitative Proteomics Group, Institute of Molecular and Cell Biology, Agency for Science Technology and Research, Singapore 138673, Singapore
| | - Jayantha Gunaratne
- Quantitative Proteomics Group, Institute of Molecular and Cell Biology, Agency for Science Technology and Research, Singapore 138673, Singapore. Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
| | - Thomas Leung
- sGSK Group, Institute of Molecular and Cell Biology, Agency for Science Technology and Research, Proteos Building, 61 Biopolis Drive, Singapore 138673, Singapore
| | - Brian Burke
- Institute of Medical Biology, 8A Biomedical Grove, #06-06 Immunos Building, Singapore 138648, Singapore
| | - Ed Manser
- sGSK Group, Institute of Molecular and Cell Biology, Agency for Science Technology and Research, Proteos Building, 61 Biopolis Drive, Singapore 138673, Singapore. Institute of Medical Biology, 8A Biomedical Grove, #06-06 Immunos Building, Singapore 138648, Singapore. Department of Pharmacology, National University of Singapore, Singapore 117597, Singapore.
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10
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Effects of protein tyrosine phosphatase-PEST are reversed by Akt in T cells. Cell Signal 2014; 26:2721-9. [PMID: 25152368 DOI: 10.1016/j.cellsig.2014.08.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 08/17/2014] [Indexed: 11/21/2022]
Abstract
T cell activation is regulated by a balance between phosphorylation and dephosphorylation that is under the control of kinases and phosphatases. Here, we examined the role of a non-receptor-type protein tyrosine phosphatase, PTP-PEST, using retrovirus-mediated gene transduction into murine T cells. Based on observations of vector markers (GFP or Thy1.1), exogenous PTP-PEST-positive CD4(+) T cells appeared within 2 days after gene transduction; the percentage of PTP-PEST-positive cells tended to decrease during a resting period in the presence of IL-2 over the next 2 days. These vector markers also showed much lower expression intensities, compared with control cells, suggesting a correlation between the percent reduction and the low marker expression intensity. A catalytically inactive PTP-PEST mutant also showed the same tendency, and stepwise deletion mutants gradually lost their ability to induce the above phenomenon. On the other hand, these PTP-PEST-transduced cells did not have an apoptotic phenotype. No difference in the total cell numbers was found in the wells of a culture plate containing VEC- and PTP-PEST-transduced T cells. Moreover, serine/threonine kinase Akt, but not the anti-apoptotic molecules Bcl-2 and Bcl-XL, reversed the phenotype induced by PTP-PEST. We discuss the novel mechanism by which Akt interferes with PTP-PEST.
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11
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Interactions between E6, FAK, and GIT1 at paxillin LD4 are necessary for transformation by bovine papillomavirus 1 E6. J Virol 2014; 88:9927-33. [PMID: 24942580 DOI: 10.1128/jvi.00552-14] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
UNLABELLED Bovine papillomavirus 1 E6 interacts with two similar proteins that regulate cell attachment and cell migration called paxillin (PXN) and HIC-5 (also known as HIC5, ARA55, HIC-5, TSC-5, and TGFB1I1). Despite the similarity between HIC-5 and paxillin, paxillin is required for E6 to transform mouse embryo fibroblasts while HIC-5 is not. Using mutants of paxillin, we found that dynamic competitive interactions between E6, focal adhesion kinase, and the GIT1 ARF-GAP protein for binding to paxillin are required but not sufficient for transformation by E6. Using mutants of paxillin and chimeric proteins between HIC-5 and paxillin, we demonstrate that a critical difference between HIC-5 and paxillin is within the LIM domains of paxillin that do not directly interact with E6. Mutational analysis indicates that at least six distinct domains of paxillin are required for E6 transformation. IMPORTANCE Papillomaviruses cause epitheliomas in vertebrates through the actions of virus-encoded oncoproteins. Despite the immense diversity of papillomavirus types, our understanding of the mechanisms by which the virus-encoded E6 oncoproteins contribute to cell transformation is restricted to human papillomavirus types that are associated with cancer. Bovine papillomavirus 1 (BPV-1) E6 has served as a model system for studies of E6 structure and function. This study examines the mechanisms by which BPV-1 E6 association with the cellular focal adhesion adapter protein paxillin contributes to cell transformation and extends our knowledge of the diverse mechanisms by which papillomaviruses transform host cells.
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12
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Ayoub E, Hall A, Scott AM, Chagnon MJ, Miquel G, Hallé M, Noda M, Bikfalvi A, Tremblay ML. Regulation of the Src kinase-associated phosphoprotein 55 homologue by the protein tyrosine phosphatase PTP-PEST in the control of cell motility. J Biol Chem 2013; 288:25739-25748. [PMID: 23897807 DOI: 10.1074/jbc.m113.501007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
PTP-PEST is a cytosolic ubiquitous protein tyrosine phosphatase (PTP) that contains, in addition to its catalytic domain, several protein-protein interaction domains that allow it to interface with several signaling pathways. Among others, PTP-PEST is a key regulator of cellular motility and cytoskeleton dynamics. The complexity of the PTP-PEST interactome underscores the necessity to identify its interacting partners and physiological substrates in order to further understand its role in focal adhesion complex turnover and actin organization. Using a modified yeast substrate trapping two-hybrid system, we identified a cytosolic adaptor protein named Src kinase-associated phosphoprotein 55 homologue (SKAP-Hom) as a novel substrate of PTP-PEST. To confirm PTP-PEST interaction with SKAP-Hom, in vitro pull down assays were performed demonstrating that the PTP catalytic domain and Proline-rich 1 (P1) domain are respectively binding to the SKAP-Hom Y260 and Y297 residues and its SH3 domain. Subsequently, we generated and rescued SKAP-Hom-deficient mouse embryonic fibroblasts (MEFs) with WT SKAP-Hom, SKAP-Hom tyrosine mutants (Y260F, Y260F/Y297F), or SKAP-Hom SH3 domain mutant (W335K). Given the role of PTP-PEST, wound-healing and trans-well migration assays were performed using the generated lines. Indeed, SKAP-Hom-deficient MEFs showed a defect in migration compared with WT-rescued MEFs. Interestingly, the SH3 domain mutant-rescued MEFs showed an enhanced cell migration corresponding potentially with higher tyrosine phosphorylation levels of SKAP-Hom. These findings suggest a novel role of SKAP-Hom and its phosphorylation in the regulation of cellular motility. Moreover, these results open new avenues by which PTP-PEST regulates cellular migration, a hallmark of metastasis.
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Affiliation(s)
- Emily Ayoub
- From the Goodman Cancer Research Centre and Department of Biochemistry, McGill University, Montreal, Quebec H3A 1A3, Canada
| | - Anita Hall
- From the Goodman Cancer Research Centre and Department of Biochemistry, McGill University, Montreal, Quebec H3A 1A3, Canada
| | - Adam M Scott
- From the Goodman Cancer Research Centre and Department of Biochemistry, McGill University, Montreal, Quebec H3A 1A3, Canada
| | - Mélanie J Chagnon
- From the Goodman Cancer Research Centre and Department of Biochemistry, McGill University, Montreal, Quebec H3A 1A3, Canada
| | - Géraldine Miquel
- INSERM U1029 and; Université Bordeaux, Avenue des Facultés, 33 405 Talence, France
| | - Maxime Hallé
- From the Goodman Cancer Research Centre and Department of Biochemistry, McGill University, Montreal, Quebec H3A 1A3, Canada
| | - Masaharu Noda
- the Division of Molecular Neurobiology, National Institute for Basic Biology, 5-1 Higashiyama, Myodaiji-cho, Okazaki, Aichi 444-8787, Japan, and
| | - Andreas Bikfalvi
- INSERM U1029 and; Université Bordeaux, Avenue des Facultés, 33 405 Talence, France
| | - Michel L Tremblay
- From the Goodman Cancer Research Centre and Department of Biochemistry, McGill University, Montreal, Quebec H3A 1A3, Canada,.
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13
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Chua GL, Patra AT, Tan SM, Bhattacharjya S. NMR structure of integrin α4 cytosolic tail and its interactions with paxillin. PLoS One 2013; 8:e55184. [PMID: 23383101 PMCID: PMC3561355 DOI: 10.1371/journal.pone.0055184] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2012] [Accepted: 12/19/2012] [Indexed: 12/24/2022] Open
Abstract
Background Integrins are a group of transmembrane signaling proteins that are important in biological processes such as cell adhesion, proliferation and migration. Integrins are α/β hetero-dimers and there are 24 different integrins formed by specific combinations of 18 α and 8 β subunits in humans. Generally, each of these subunits has a large extracellular domain, a single pass transmembrane segment and a cytosolic tail (CT). CTs of integrins are important in bidirectional signal transduction and they associate with a large number of intracellular proteins. Principal Findings Using NMR spectroscopy, we determined the 3-D structure of the full-length α4 CT (Lys968-Asp999) and characterize its interactions with the adaptor protein paxillin. The α4 CT assumes an overall helical structure with a kink in its membrane proximal region. Residues Gln981-Asn997 formed a continuous helical conformation that may be sustained by potential ionic and/or hydrogen bond interactions and packing of aromatic-aliphatic side-chains. 15N-1H HSQC NMR experiments reveal interactions of the α4 CT C-terminal region with a fragment of paxillin (residues G139-K277) that encompassed LD2-LD4 repeats. Residues of these LD repeats including their adjoining linkers showed α4 CT binding-induced chemical shift changes. Furthermore, NMR studies using LD-containing peptides showed predominant interactions between LD3 and LD4 of paxillin and α4 CT. Docked structures of the α4 CT with these LD repeats suggest possible polar and/or salt-bridge and non-polar packing interactions. Significance The current study provides molecular insights into the structural diversity of α CTs of integrins and interactions of integrin α4 CT with the adaptor protein paxillin.
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Affiliation(s)
- Geok-Lin Chua
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Alok Tanala Patra
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Suet-Mien Tan
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- * E-mail: (SB); (SMT)
| | - Surajit Bhattacharjya
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- * E-mail: (SB); (SMT)
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14
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Coló GP, Hernández-Varas P, Lock J, Bartolomé RA, Arellano-Sánchez N, Strömblad S, Teixidó J. Focal adhesion disassembly is regulated by a RIAM to MEK-1 pathway. J Cell Sci 2012; 125:5338-52. [PMID: 22946047 DOI: 10.1242/jcs.105270] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Cell migration and invasion require regulated turnover of integrin-dependent adhesion complexes. Rap1-GTP-interacting adaptor molecule (RIAM) is an adaptor protein that mediates talin recruitment to the cell membrane, and whose depletion leads to defective melanoma cell migration and invasion. In this study, we investigated the potential involvement of RIAM in focal adhesion (FA) dynamics. RIAM-depleted melanoma and breast carcinoma cells displayed an increased number, size and stability of FAs, which accumulated centrally at the ventral cell surface, a phenotype caused by defective FA disassembly. Impairment in FA disassembly resulting from RIAM knockdown correlated with deficient integrin-dependent mitogen-activated protein kinase kinase (MEK)-Erk1/2 activation and, importantly, overexpression of constitutively active MEK resulted in rescue of FA disassembly and recovery of cell invasion. Furthermore, RIAM-promoted Ras homologue gene family, member A (RhoA) activation following integrin engagement was needed for subsequent Erk1/2 activation. In addition, RhoA overexpression partially rescued the FA phenotype in RIAM-depleted cells, also suggesting a functional role for RhoA downstream of RIAM, but upstream of Erk1/2. RIAM knockdown also led to enhanced phosphorylation of paxillin Tyr118 and Tyr31. However, expression of phosphomimetic and nonphosphorylatable mutants at these paxillin residues indicated that paxillin hyperphosphorylation is a subsequent consequence of the blockade of FA disassembly, but does not cause the FA phenotype. RIAM depletion also weakened the association between FA proteins, suggesting that it has important adaptor roles in the correct assembly of adhesion complexes. Our data suggest that integrin-triggered, RIAM-dependent MEK activation represents a key feedback event required for efficient FA disassembly, which could help explain the role of RIAM in cell migration and invasion.
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Affiliation(s)
- Georgina P Coló
- Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas (CSIC), 28040 Madrid, Spain
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15
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Romanova LY, Mushinski JF. Central role of paxillin phosphorylation in regulation of LFA-1 integrins activity and lymphocyte migration. Cell Adh Migr 2012; 5:457-62. [PMID: 22274710 DOI: 10.4161/cam.5.6.18219] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Coordinated changes of actin cytoskeleton and cell adhesion accompany maturation of lymphoid cells, their migration through lymphoid organs and to sites of inflammation, as well as metastasis of transformed cells. Here we discuss the central role of the actin-regulating adaptor protein, paxillin, during lymphocyte transition from a polarized, motile cell phenotype with partially active LFA-1 integrins to a round and immobile one with fully active LFA-1. In Baf3 murine pro-B lymphocytes, the former phenotype is induced by IL-3 that stimulates a FAK-mediated phosphorylation of paxillin at tyrosines (Y) 31 and 118 and a consequent Rac1 activation. Rearrangements of actin cytoskeleton that lead to the cell's acquisition of a spherical shape and LFA-1 activation are achieved upon activation of PKC-δ that binds and directly phosphorylates paxillin at threonine (T) 538 with consequent RhoA activation. This is accompanied by dephosphorylation of paxillin Y31/118 and by Rac1 inactivation. We propose a model of signaling cascades that reflects the interplay between the IL-3- and PKC-δ-mediated pathways.
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Affiliation(s)
- Larisa Y Romanova
- Laboratory of Cancer Biology and Genetics, National Cancer Institute, NIH, Bethesda, MD, USA.
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16
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Tyrosine-Protein Phosphatase Nonreceptor Type 12 Is a Novel Prognostic Biomarker for Esophageal Squamous Cell Carcinoma. Ann Thorac Surg 2012; 93:1674-80. [DOI: 10.1016/j.athoracsur.2011.12.056] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2011] [Revised: 12/13/2011] [Accepted: 12/16/2011] [Indexed: 12/11/2022]
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17
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Sero JE, Thodeti CK, Mammoto A, Bakal C, Thomas S, Ingber DE. Paxillin mediates sensing of physical cues and regulates directional cell motility by controlling lamellipodia positioning. PLoS One 2011; 6:e28303. [PMID: 22194823 PMCID: PMC3237434 DOI: 10.1371/journal.pone.0028303] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Accepted: 11/05/2011] [Indexed: 12/17/2022] Open
Abstract
Physical interactions between cells and the extracellular matrix (ECM) guide directional migration by spatially controlling where cells form focal adhesions (FAs), which in turn regulate the extension of motile processes. Here we show that physical control of directional migration requires the FA scaffold protein paxillin. Using single-cell sized ECM islands to constrain cell shape, we found that fibroblasts cultured on square islands preferentially activated Rac and extended lamellipodia from corner, rather than side regions after 30 min stimulation with PDGF, but that cells lacking paxillin failed to restrict Rac activity to corners and formed small lamellipodia along their entire peripheries. This spatial preference was preceded by non-spatially constrained formation of both dorsal and lateral membrane ruffles from 5-10 min. Expression of paxillin N-terminal (paxN) or C-terminal (paxC) truncation mutants produced opposite, but complementary, effects on lamellipodia formation. Surprisingly, pax-/- and paxN cells also formed more circular dorsal ruffles (CDRs) than pax+ cells, while paxC cells formed fewer CDRs and extended larger lamellipodia even in the absence of PDGF. In a two-dimensional (2D) wound assay, pax-/- cells migrated at similar speeds to controls but lost directional persistence. Directional motility was rescued by expressing full-length paxillin or the N-terminus alone, but paxN cells migrated more slowly. In contrast, pax-/- and paxN cells exhibited increased migration in a three-dimensional (3D) invasion assay, with paxN cells invading Matrigel even in the absence of PDGF. These studies indicate that paxillin integrates physical and chemical motility signals by spatially constraining where cells will form motile processes, and thereby regulates directional migration both in 2D and 3D. These findings also suggest that CDRs may correspond to invasive protrusions that drive cell migration through 3D extracellular matrices.
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Affiliation(s)
- Julia E. Sero
- Vascular Biology Program, Departments of Pathology and Surgery, Children's Hospital Boston and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Charles K. Thodeti
- Vascular Biology Program, Departments of Pathology and Surgery, Children's Hospital Boston and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Akiko Mammoto
- Vascular Biology Program, Departments of Pathology and Surgery, Children's Hospital Boston and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Chris Bakal
- Dynamical Cell Systems Team, Division of Cancer Biology, Institute of Cancer Research, London, United Kingdom
| | - Sheila Thomas
- Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Donald E. Ingber
- Vascular Biology Program, Departments of Pathology and Surgery, Children's Hospital Boston and Harvard Medical School, Boston, Massachusetts, United States of America
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts, United States of America
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, United States of America
- * E-mail:
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18
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Wade R, Brimer N, Lyons C, Pol SV. Paxillin enables attachment-independent tyrosine phosphorylation of focal adhesion kinase and transformation by RAS. J Biol Chem 2011; 286:37932-37944. [PMID: 21900245 DOI: 10.1074/jbc.m111.294504] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Paxillin and HIC5 are closely related adapter proteins that regulate cell migration and are tyrosine-phosphorylated by focal adhesion kinase (FAK). Paxillin, HIC5, and FAK tyrosine phosphorylation increase upon cell attachment and decrease upon detachment from extracellular matrix. Unexpectedly, we found that although FAK tyrosine phosphorylation in attached cells did not require paxillin, in detached fibroblasts there was remaining FAK tyrosine phosphorylation that required expression of paxillin and was not supported by HIC5. The support of attachment-independent FAK tyrosine phosphorylation required the paxillin LIM domains and suggested that paxillin might facilitate oncogenic transformation. Paxillin but not HIC5 augmented anchorage-independent cell proliferation induced by RAS. Both anchorage-independent FAK tyrosine phosphorylation and RAS-induced colony formation required multiple docking sites on paxillin, including LD4 (docking sites for FAK-Src and GIT1/2-PIX-NCK-PAK complex), LD5, and all four carboxyl-terminal LIM domains (that bind tubulin and PTP-PEST). Analysis using paxillin mutants dissociated domains of paxillin that are required for regulation of cell migration from domains that are required for anchorage-independent cell proliferation and demonstrated essential functions of the paxillin LIM domains that are not found in HIC5 LIM domains. These results highlight the role of paxillin in facilitating attachment-independent signal transduction implicated in cancer.
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Affiliation(s)
- Ramon Wade
- Department of Pathology, University of Virginia, Charlottesville, Virginia 22908
| | - Nicole Brimer
- Department of Pathology, University of Virginia, Charlottesville, Virginia 22908
| | - Charles Lyons
- Department of Pathology, University of Virginia, Charlottesville, Virginia 22908
| | - Scott Vande Pol
- Department of Pathology, University of Virginia, Charlottesville, Virginia 22908.
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19
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Romanova LY, Holmes G, Bahte SK, Kovalchuk AL, Nelson PJ, Ward Y, Gueler F, Mushinski JF. Phosphorylation of paxillin at threonine 538 by PKCdelta regulates LFA1-mediated adhesion of lymphoid cells. J Cell Sci 2010; 123:1567-77. [PMID: 20388733 DOI: 10.1242/jcs.060996] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We investigated the PKCdelta-mediated phosphorylation of paxillin within its LIM4 domain and the involvement of this phosphorylation in activation of LFA-1 integrins of the Baf3 pro-B lymphocytic cell line. Using phosphorylated-threonine-specific antibodies, phosphorylated amino acid analysis and paxillin phosphorylation mutants, we demonstrated that TPA, the pharmacological analog of the endogenous second messenger diacyl glycerol, stimulates paxillin phosphorylation at threonine 538 (T538). The TPA-responsive PKC isoform PKCdelta directly binds paxillin in a yeast two-hybrid assay and phosphorylates paxillin at T538 in vitro and also co-immunoprecipitates with paxillin and mediates phosphorylation of this residue in vivo. Recombinant wild-type paxillin, its phospho-inhibitory T538A or phospho-mimetic T538E mutants were expressed in the cells simultaneously with siRNA silencing of the endogenous paxillin. These experiments suggest that phosphorylation of paxillin T538 contributes to dissolution of the actin cytoskeleton, redistribution of LFA-1 integrins and an increase in their affinity. We also show that phosphorylation of T538 is involved in the activation of LFA-1 integrins by TPA.
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Affiliation(s)
- Larisa Y Romanova
- Laboratory of Cancer Biology and Genetics, Cell and Cancer Biology Branch, National Cancer Institute, NIH, Bethesda, MD 20892, USA.
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20
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Mao Y, Schwarzbauer JE. Accessibility to the Fibronectin Synergy Site in a 3D Matrix Regulates Engagement of α 5β 1 versus α vβ 3 Integrin Receptors. ACTA ACUST UNITED AC 2009; 13:267-77. [PMID: 17162669 DOI: 10.1080/15419060601072215] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Cell adhesion and migration on fibronectin (FN) extracellular matrix are mediated by integrin receptors. Integrins alpha5beta1 and alphavbeta3 require the RGD cell-binding sequence in FN, but alpha5beta1 also requires the nearby synergy site for maximal binding. In this study, we investigated how differences in the numbers of RGD or synergy sites within a three-dimensional (3D) FN-rich matrix influence cell adhesion and migration. CHO cell adhesion, spreading, and migration were reduced on 3D chimeric matrix containing FN lacking RGD (FN(RGD-)). Incorporation of FN with mutation of the synergy site (FN(syn-)), however, resulted in selective usage of integrins. CHO cells expressing alpha5beta1 showed decreased interactions with FN(syn-) chimeric matrix. In contrast, the presence of FN(syn-) had no effect on CHOalphavbeta3 cell migration. Interestingly, CHOalpha5/alphavbeta3 cells expressing both integrins selectively used alpha5beta1 for migration on wild type FN matrix but preferred alphavbeta3 for migration on FN(syn-) chimeric matrix. Thus sequestration or exposure of the FN synergy site within a 3D matrix may represent a novel mechanism for regulating cell functions through differential usage of integrin receptors. [Supplementary materials are available for this article. Go to the publisher's online edition of Cell Communication and Adhesion for the following free supplemental resource: a video recording shows migration of HT1080 cells on 3D matrix. HT1080 cells were allowed to attach to the matrix in serum-free DMEM for 2 h. FBS was then added to the medium to a final concentration of 10% and video recording was started. Images were taken every 5 min for 2 h. The video plays at 6 frames/s.].
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Affiliation(s)
- Yong Mao
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544-1014, USA
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21
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Veillette A, Rhee I, Souza CM, Davidson D. PEST family phosphatases in immunity, autoimmunity, and autoinflammatory disorders. Immunol Rev 2009; 228:312-24. [PMID: 19290936 DOI: 10.1111/j.1600-065x.2008.00747.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The proline-, glutamic acid-, serine- and threonine-rich (PEST) family of protein tyrosine phosphatases (PTPs) includes proline-enriched phosphatase (PEP)/lymphoid tyrosine phosphatase (LYP), PTP-PEST, and PTP-hematopoietic stem cell fraction (HSCF). PEP/LYP is a potent inhibitor of T-cell activation, principally by suppressing the activity of Src family protein tyrosine kinases (PTKs). This function seems to be dependent, at least in part, on the ability of PEP to bind C-terminal Src kinase (Csk), a PTK also involved in inactivating Src kinases. Interestingly, a polymorphism of LYP in humans (R620W) is a significant risk factor for autoimmune diseases including type 1 diabetes, rheumatoid arthritis, and lupus. The R620W mutation may be a 'gain-of-function' mutation. In non-hematopoietic cells, PTP-PEST is a critical regulator of adhesion and migration. This effect correlates with the aptitude of PTP-PEST to dephosphorylate cytoskeletal proteins such as Cas, focal adhesion associated-kinase (FAK), Pyk2, and PSTPIP. While not established, a similar function may also exist in immune cells. Additionally, overexpression studies provided an indication that PTP-PEST may be a negative regulator of lymphocyte activation. Interestingly, mutations in a PTP-PEST- and PTP-HSCF-interacting protein, PSTPIP1, were identified in humans with pyogenic sterile arthritis, pyoderma gangrenosum, and acne (PAPA) syndrome and familial recurrent arthritis, two autoinflammatory diseases. These mutations abrogate the ability of PSTPIP1 to bind PTP-PEST and PTP-HSCF, suggesting that these two PTPs may be negative regulators of inflammation.
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Affiliation(s)
- André Veillette
- Laboratory of Molecular Oncology, Clinical Research Institute of Montréal, Montréal, Québec, Canada.
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22
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Zouq NK, Keeble JA, Lindsay J, Valentijn AJ, Zhang L, Mills D, Turner CE, Streuli CH, Gilmore AP. FAK engages multiple pathways to maintain survival of fibroblasts and epithelia: differential roles for paxillin and p130Cas. J Cell Sci 2009; 122:357-67. [PMID: 19126677 DOI: 10.1242/jcs.030478] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Different cell types interpret their distinct extracellular matrix (ECM) environments to bring about specific cell fate decisions, and can differentiate or undergo apoptosis depending on their local adhesive interactions. Apoptosis in response to an inappropriate ECM environment is termed ;anoikis', or homelessness. Several studies, utilising a variety of cell types, have indicated a common, crucial role for focal adhesion kinase (FAK) in suppressing anoikis. A wide range of different integrins can activate FAK, raising the question of how cell type specific effects are regulated. In this study, we have used a constitutively active form of FAK to examine the mechanism of FAK-mediated survival signalling in cell types from distinct embryonic lineages that show differing sensitivities to anoikis. We demonstrate that both fibroblasts and epithelial cells prevent anoikis through FAK activation. We show that FAK activates multiple downstream pathways in order to suppress anoikis. However FAK regulates survival through a more restricted set of pathways in the more anoikis-sensitive epithelial cells. Furthermore, we identify a novel role for paxillin in apoptosis suppression.
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Affiliation(s)
- Nadia K Zouq
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, UK
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23
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Abstract
Paxillin is a multi-domain scaffold protein that localizes to the intracellular surface of sites of cell adhesion to the extracellular matrix. Through the interactions of its multiple protein-binding modules, many of which are regulated by phosphorylation, paxillin serves as a platform for the recruitment of numerous regulatory and structural proteins that together control the dynamic changes in cell adhesion, cytoskeletal reorganization and gene expression that are necessary for cell migration and survival. In particular, paxillin plays a central role in coordinating the spatial and temporal action of the Rho family of small GTPases, which regulate the actin cytoskeleton, by recruiting an array of GTPase activator, suppressor and effector proteins to cell adhesions. When paxillin was first described 18 years ago, the amazing complexity of cell-adhesion organization, dynamics and signaling was yet to be realized. Herein we highlight our current understanding of how the multiple protein interactions of paxillin contribute to the coordination of cell-adhesion function.
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Affiliation(s)
- Nicholas O Deakin
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
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24
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Arimura Y, Vang T, Tautz L, Williams S, Mustelin T. TCR-induced downregulation of protein tyrosine phosphatase PEST augments secondary T cell responses. Mol Immunol 2008; 45:3074-84. [PMID: 18457880 DOI: 10.1016/j.molimm.2008.03.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2007] [Revised: 03/10/2008] [Accepted: 03/11/2008] [Indexed: 11/19/2022]
Abstract
We report that the protein tyrosine phosphatase PTP-PEST is expressed in resting human and mouse CD4(+) and CD8(+) T cells, but not in Jurkat T leukemia cells, and that PTP-PEST protein, but not mRNA, was dramatically downregulated in CD4(+) and CD8(+) primary human T cells upon T cell activation. This was also true in mouse CD4(+) T cells, but less striking in mouse CD8(+) T cells. PTP-PEST reintroduced into Jurkat at levels similar to those in primary human T cells, was a potent inhibitor of TCR-induced transactivation of reporter genes driven by NFAT/AP-1 and NF-kappaB elements and by the entire IL-2 gene promoter. Introduction of PTP-PEST into previously activated primary human T cells also reduced subsequent IL-2 production by these cells in response to TCR and CD28 stimulation. The inhibitory effect of PTP-PEST was associated with dephosphorylation the Lck kinase at its activation loop site (Y394), reduced early TCR-induced tyrosine phosphorylation, reduced ZAP-70 phosphorylation and inhibition of MAP kinase activation. We propose that PTP-PEST tempers T cell activation by dephosphorylating TCR-proximal signaling molecules, such as Lck, and that down-regulation of PTP-PEST may be a reason for the increased response to TCR triggering of previously activated T cells.
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MESH Headings
- Animals
- CSK Tyrosine-Protein Kinase
- Down-Regulation
- Gene Expression Regulation, Enzymologic
- Humans
- Immunologic Memory
- Jurkat Cells
- Leukemia/enzymology
- Leukemia/pathology
- Lymphocyte Activation
- Lymphocyte Specific Protein Tyrosine Kinase p56(lck)/metabolism
- Membrane Microdomains/enzymology
- Mice
- Mice, Inbred C57BL
- Phosphorylation
- Phosphotyrosine/metabolism
- Protein Tyrosine Phosphatase, Non-Receptor Type 12/genetics
- Protein Tyrosine Phosphatase, Non-Receptor Type 12/metabolism
- Protein-Tyrosine Kinases/metabolism
- Proto-Oncogene Proteins/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Antigen, T-Cell/immunology
- Receptors, Antigen, T-Cell/metabolism
- Signal Transduction
- T-Lymphocytes/enzymology
- T-Lymphocytes/immunology
- Transcriptional Activation
- src-Family Kinases
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Affiliation(s)
- Yutaka Arimura
- Infectious and Inflammatory Disease Center, Burnham Institute for Medical Research, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA.
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25
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Yamauchi J, Miyamoto Y, Kusakawa S, Torii T, Mizutani R, Sanbe A, Nakajima H, Kiyokawa N, Tanoue A. Neurofibromatosis 2 tumor suppressor, the gene induced by valproic acid, mediates neurite outgrowth through interaction with paxillin. Exp Cell Res 2008; 314:2279-88. [PMID: 18486129 DOI: 10.1016/j.yexcr.2008.03.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2008] [Revised: 03/26/2008] [Accepted: 03/29/2008] [Indexed: 01/10/2023]
Abstract
Valproic acid (VPA), the drug for bipolar disorder and epilepsy, has a potent ability to induce neuronal differentiation, yet comparatively little is presently known about the underlying mechanism. We previously demonstrated that c-Jun N-terminal kinase (JNK) phosphorylation of the focal adhesion protein paxillin mediates differentiation in N1E-115 neuroblastoma cells. Here, we show that VPA up-regulates the neurofibromatosis type 2 (NF2) tumor suppressor, merlin, to regulate neurite outgrowth through the interaction with paxillin. The inhibition of merlin function by its knockdown or expression of merlin harboring the Gln-538-to-Pro mutation, a naturally occurring NF2 missense mutation deficient in linking merlin to the actin cytoskeleton, decreases VPA-induced neurite outgrowth. Importantly, the expression of merlin by itself is not sufficient to induce neurite outgrowth, which requires co-expression with paxillin, the binding partner of merlin. In fact, the missense mutation Trp-60-to-Cys or Phe-62-to-Ser, that is deficient in binding to paxillin, reduces neurite outgrowth induced by VPA. In addition, co-expression of a paxillin construct harboring the mutation at the JNK phosphorylation site with merlin results in blunted induction of the outgrowth. We also find that the first LIM domain of paxillin is a major binding region with merlin and that expression of the isolated first LIM domain blocks the effects of VPA. Furthermore, similar findings that merlin regulates neurite outgrowth through the interaction with paxillin have been observed in several kinds of neuronal cells. These results suggest that merlin is an as yet unknown regulator of neurite outgrowth through the interaction with paxillin, providing a possibly common mechanism regulating neurite formation.
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Affiliation(s)
- Junji Yamauchi
- Department of Pharmacology, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya, Tokyo 157-8535, Japan.
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26
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Abstract
Papillomavirus E6 proteins are adapters that change the function of cellular regulatory proteins. The bovine papillomavirus type 1 E6 (BE6) binds to LXXLL peptide sequences termed LD motifs (consensus sequence LDXLLXXL) on the cellular protein paxillin that is a substrate of Src and focal adhesion kinases. Anchorage-independent transformation induced by BE6 required both paxillin and BE6-binding LD motifs on paxillin but was independent of the major tyrosine phosphorylation sites of paxillin. The essential role of paxillin in transformation by BE6 highlights the role of paxillin in the transduction of cellular signals that result in anchorage-independent cell proliferation.
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27
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Granot-Attas S, Elson A. Protein tyrosine phosphatases in osteoclast differentiation, adhesion, and bone resorption. Eur J Cell Biol 2008; 87:479-90. [PMID: 18342392 DOI: 10.1016/j.ejcb.2008.01.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2007] [Revised: 01/16/2008] [Accepted: 01/16/2008] [Indexed: 01/06/2023] Open
Abstract
Osteoclasts are large cells derived from the monocyte-macrophage hematopoietic cell lineage. Their primary function is to degrade bone in various physiological contexts. Osteoclasts adhere to bone via podosomes, specialized adhesion structures whose structure and subcellular organization are affected by mechanical contact of the cell with bone matrix. Ample evidence indicates that reversible tyrosine phosphorylation of podosomal proteins plays a major role in determining the organization and dynamics of podosomes. Although roles of several tyrosine kinases are known in detail in this respect, little is known concerning the roles of protein tyrosine phosphatases (PTPs) in regulating osteoclast adhesion. Here we summarize available information concerning the known and hypothesized roles of the best-researched PTPs in osteoclasts - PTPRO, PTP epsilon, SHP-1, and PTP-PEST. Of these, PTPRO, PTP epsilon, and PTP-PEST appear to support osteoclast activity while SHP-1 inhibits it. Additional studies are required to provide full molecular details of the roles of these PTPs in regulating osteoclast adhesion, and to uncover additional PTPs that participate in this process.
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Affiliation(s)
- Shira Granot-Attas
- Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot 76100, Israel
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Hallé M, Liu YC, Hardy S, Théberge JF, Blanchetot C, Bourdeau A, Meng TC, Tremblay ML. Caspase-3 regulates catalytic activity and scaffolding functions of the protein tyrosine phosphatase PEST, a novel modulator of the apoptotic response. Mol Cell Biol 2006; 27:1172-90. [PMID: 17130234 PMCID: PMC1800677 DOI: 10.1128/mcb.02462-05] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The protein tyrosine phosphatase PEST (PTP-PEST) is involved in the regulation of the actin cytoskeleton. Despite the emerging functions attributed to both PTPs and the actin cytoskeleton in apoptosis, the involvement of PTP-PEST in apoptotic cell death remains to be established. Using several cell-based assays, we showed that PTP-PEST participates in the regulation of apoptosis. As apoptosis progressed, a pool of PTP-PEST localized to the edge of retracting lamellipodia. Expression of PTP-PEST also sensitized cells to receptor-mediated apoptosis. Concertedly, specific degradation of PTP-PEST was observed during apoptosis. Pharmacological inhibitors, immunodepletion experiments, and in vitro cleavage assays identified caspase-3 as the primary regulator of PTP-PEST processing during apoptosis. Caspase-3 specifically cleaved PTP-PEST at the (549)DSPD motif and generated fragments, some of which displayed increased catalytic activity. Moreover, caspase-3 regulated PTP-PEST interactions with paxillin, leupaxin, Shc, and PSTPIP. PTP-PEST acted as a scaffolding molecule connecting PSTPIP to additional partners: paxillin, Shc, Csk, and activation of caspase-3 correlated with the modulation of the PTP-PEST adaptor function. In addition, cleavage of PTP-PEST facilitated cellular detachment during apoptosis. Together, our data demonstrate that PTP-PEST actively contributes to the cellular apoptotic response and reveal the importance of caspases as regulators of PTPs in apoptosis.
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Affiliation(s)
- Maxime Hallé
- Institute of Biological Chemistry, Academia Sinica, 128 Academia Road, Section 2, Nankang 115, Taipei, Taiwan
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29
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Abou Zeid N, Vallés AM, Boyer B. Serine phosphorylation regulates paxillin turnover during cell migration. Cell Commun Signal 2006; 4:8. [PMID: 17121676 PMCID: PMC1664571 DOI: 10.1186/1478-811x-4-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2006] [Accepted: 11/22/2006] [Indexed: 12/15/2022] Open
Abstract
Background Paxillin acts as an adaptor protein that localizes to focal adhesion. This protein is regulated during cell migration by phosphorylation on tyrosine, serine and threonine residues. Most of these phosphorylations have been implicated in the regulation of different steps of cell migration. The two major phosphorylation sites of paxillin in response to adhesion to an extracellular matrix are serines 188 and 190. However, the function of this phosphorylation event remains unknown. The purpose of this work was to determine the role of paxillin phosphorylation on residues S188 and S190 in the regulation of cell migration. Results We used NBT-II epithelial cells that can be induced to migrate when plated on collagen. To examine the role of paxillin serines 188/190 in cell migration, we constructed an EGFP-tagged paxillin mutant in which S188/S190 were mutated into unphosphorylatable alanine residues. We provide evidence that paxillin is regulated by proteasomal degradation following polyubiquitylation of the protein. During active cell migration on collagen, paxillin is protected from proteasome-dependent degradation. We demonstrate that phosphorylation of serines 188/190 is necessary for the protective effect of collagen. In an effort to understand the physiological relevance of paxillin protection from degradation, we show that cells expressing the paxillin S188/190A interfering mutant spread less, have reduced protrusive activity but migrate more actively. Conclusion Our data demonstrate for the first time that serine-regulated degradation of paxillin plays a key role in the modulation of membrane dynamics and consequently, in the control of cell motility.
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Affiliation(s)
- Nancy Abou Zeid
- Institut Curie, CNRS UMR146, Centre Universitaire, Orsay, France
| | - Ana-Maria Vallés
- Institut Curie, CNRS UMR146, Centre Universitaire, Orsay, France
| | - Brigitte Boyer
- Laboratoire de Génétique Moléculaire du Développement INSERM UR784, Département de Biologie, Ecole Normale Supérieure, 46 rue d'Ulm 75005, Paris, France
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30
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Streit S, Ruhe JE, Knyazev P, Knyazeva T, Iacobelli S, Peter S, Hoefler H, Ullrich A. PTP-PEST phosphatase variations in human cancer. ACTA ACUST UNITED AC 2006; 170:48-53. [PMID: 16965954 DOI: 10.1016/j.cancergencyto.2006.05.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2005] [Revised: 04/02/2006] [Accepted: 05/08/2006] [Indexed: 10/24/2022]
Abstract
Signal transduction via tyrosine phosphorylation, normally fine-tuned by the concerted action of both protein tyrosine kinases and protein tyrosine phosphatases (PTPs), is a key mechanism in tumorigenesis. PTP-PEST, a ubiquitously expressed cytoplasmic tyrosine phosphatase, is thought to play an important role in cell adhesion and motility, and may be involved in metastasis. A search for sequence variations within the gene PTPN12 (alias PTP-PEST) was performed in breast cancer cell lines, leading to the identification of three amino acid substitutions at positions 322, 573, and 709. These alterations were also found in squamous cell carcinoma cell lines and could be verified in primary human breast and kidney tumor samples. Analysis of peripheral blood samples confirmed the germline origin of these alterations. Furthermore, functional characterization of the Ile322 and Ala573 PTP-PEST mutants revealed an enhancement of in vitro phosphatase activity, whereas the Lys709 variant showed reduced catalytic activity. These data demonstrate the existence of PTP-PEST variants that might be meaningful for human cancer and underscore the need for further characterizing PTP-PEST and its signaling pathways in context of this disease.
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Affiliation(s)
- Sylvia Streit
- Department of Molecular Biology, Max-Planck-Institute of Biochemistry, Am Klopferspitz 18a, D-82152 Martinsried, Germany.
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Playford MP, Lyons PD, Sastry SK, Schaller MD. Identification of a filamin docking site on PTP-PEST. J Biol Chem 2006; 281:34104-12. [PMID: 16973606 DOI: 10.1074/jbc.m606277200] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
PTP-PEST is a cytoplasmic protein-tyrosine phosphatase (PTP) implicated in the regulation of biological processes such as cell motility, cytokinesis, focal adhesion disassembly, and lymphocyte activation. Using a proteomics approach, filamin-A was identified as a novel interacting protein that bound to GST-PTP-PEST. This interaction was confirmed in vitro and in cells by coimmunoprecipitation. The site of filamin interaction on PTP-PEST was mapped to the fourth proline-rich region (Pro4). PTP-PEST has previously been implicated in the regulation of cytokinesis. In further support of this finding, expression of PTP-PEST in HeLa cells resulted in the formation of multinucleated cells. A PTP-PEST mutant lacking Pro4 and unable to bind filamin-A failed to induce the multinucleated phenotype. Further, depletion of filamin-A in HeLa cells was found to reduce the PTP-PEST-dependent multinucleation phenotype. Hence, we conclude that the interaction of PTP-PEST with filamin-A may function in the control of cytokinesis in mammalian cells.
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Affiliation(s)
- Martin P Playford
- Department of Cell and Developmental Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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Sirois J, Côté JF, Charest A, Uetani N, Bourdeau A, Duncan SA, Daniels E, Tremblay ML. Essential function of PTP-PEST during mouse embryonic vascularization, mesenchyme formation, neurogenesis and early liver development. Mech Dev 2006; 123:869-80. [PMID: 17070019 PMCID: PMC4671782 DOI: 10.1016/j.mod.2006.08.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2005] [Revised: 08/03/2006] [Accepted: 08/28/2006] [Indexed: 11/29/2022]
Abstract
PTP (protein-tyrosine phosphatase)-PEST is a ubiquitously expressed cellular regulator of integrin signalling. It has been shown to bind several molecules such as Shc, paxillin and Grb2, that are involved downstream of FAK (focal adhesion kinase) pathway. Through its specific association to p130cas and further dephosphorylation, PTP-PEST plays a critical role in cell-matrix interactions, which are essential during embryogenesis. We report here that ablation of the gene leads to early embryonic lethality, correlating well with the high expression of the protein during embryonic development. We observed an increased level of tyrosine phosphorylation of p130cas protein in E9.5 PTP-PEST(-/-) embryos, a first evidence of biochemical defect leading to abnormal growth and development. Analysis of null mutant embryos revealed that they reach gastrulation, initiate yolk sac formation, but fail to progress through normal subsequent developmental events. E9.5-10.5 PTP-PEST(-/-) embryos had morphological abnormalities such as defective embryo turning, improper somitogenesis and vasculogenesis, impaired liver development, accompanied by degeneration in both neuroepithelium and somatic epithelia. Moreover, in embryos surviving until E10.5, the caudal region was truncated, with severe mesenchyme deficiency and no successful liver formation. Defects in embryonic mesenchyme as well as subsequent failure of proper vascularization, liver development and somatogenesis, seemed likely to induce lethality at this stage of development, and these results confirm that PTP-PEST plays an essential function in early embryogenesis.
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Affiliation(s)
- Jacinthe Sirois
- McGill Cancer Center and Biochemistry Department, McGill University, 3655 Sir William Osler Promenade, Montreal, QUE, Canada H3G 1Y6
| | - Jean-François Côté
- Clinical Research Institute of Montreal, 110 pine Avenue West, Montreal, QUE, Canada H2W 1R7
| | - Alain Charest
- Center for Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Noriko Uetani
- McGill Cancer Center and Biochemistry Department, McGill University, 3655 Sir William Osler Promenade, Montreal, QUE, Canada H3G 1Y6
| | - Annie Bourdeau
- McGill Cancer Center and Biochemistry Department, McGill University, 3655 Sir William Osler Promenade, Montreal, QUE, Canada H3G 1Y6
| | - Stephen A. Duncan
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Eugene Daniels
- Department of Anatomy and Cell Biology, McGill University, Montreal, QUE, Canada H3G 1Y6
- Corresponding authors. Tel./fax: +1 514 398 8280. (E. Daniels)
| | - Michel L. Tremblay
- McGill Cancer Center and Biochemistry Department, McGill University, 3655 Sir William Osler Promenade, Montreal, QUE, Canada H3G 1Y6
- Corresponding authors. Tel./fax: +1 514 398 8280. (E. Daniels)
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McGarrigle D, Shan D, Yang S, Huang XY. Role of Tyrosine Kinase Csk in G Protein-coupled Receptor- and Receptor Tyrosine Kinase-induced Fibroblast Cell Migration. J Biol Chem 2006; 281:10583-8. [PMID: 16501257 DOI: 10.1074/jbc.m513002200] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tyrosine kinase Csk is essential for mouse embryonic development. Csk knock-out mice died at early stages of embryogenesis (around embryonic day 10). The molecular mechanism for this defect is not completely understood. Here we report that Csk deficiency in mouse embryonic fibroblast cells blocked cell migration induced by lysophosphatidic acid through G protein-coupled receptors, by platelet-derived growth factor and epidermal growth factor through receptor tyrosine kinases, and by serum. Re-expression of Csk in these Csk-deficient cells rescued the migratory phenotype. Furthermore, deletion of Csk did not interfere with Rac activation and lamellipodia formation, but impaired the focal adhesions. Our data demonstrate a critical role for Csk in cell migration.
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Affiliation(s)
- Deirdre McGarrigle
- Department of Physiology, Cornell University Weill Medical College, New York, NY 10021, USA
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Wade R, Vande Pol S. Minimal features of paxillin that are required for the tyrosine phosphorylation of focal adhesion kinase. Biochem J 2006; 393:565-73. [PMID: 16253116 PMCID: PMC1360707 DOI: 10.1042/bj20051241] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Tyrosine phosphorylation of FAK (focal adhesion kinase) regulates signalling that results from the interaction of integrins with extracellular matrix and growth factor receptors. A critical step in this process is the phosphorylation of Tyr397 of FAK, which creates a binding site for Src family kinases, PI3K (phosphoinositide 3-kinase) and Shc (Src homology and collagen homology). An intact Tyr397 site is required for FAK-mediated regulation of cell migration, survival signals and full responsiveness to soluble growth factors. We showed previously that the adaptor protein paxillin is required for the overall tyrosine phosphorylation of FAK in embryonic stem cells [Wade, Bohl and Vande Pol (2002) Oncogene 21, 96-107]. In the present paper, we identify the minimal structural features of paxillin that are required to support overall FAK tyrosine phosphorylation and Tyr397 phosphorylation. Paxillin contains N-terminal leucine-rich LD motifs that bind directly to FAK and four LIM (Lin-11, Isl-1 and Mec-3) domains in the C-terminus. We show that paxillin LIM domains 1, 2 and 3 are each required for FAK tyrosine phosphorylation, while LIM4 is dispensable. In addition to paxillin LIM domains 1, 2 and 3, a single LD motif on paxillin is required to support FAK tyrosine phosphorylation in embryonic stem cells. Both sequence and spatial requirements exist for LD motifs to support FAK tyrosine phosphorylation. Interestingly, synthetic LD motifs that fail to bind FAK in vitro are able to fully support FAK tyrosine phosphorylation, indicating that minimal interactions of LD motifs with FAK suffice. Our results demonstrate at least four distinct structural domains of paxillin support at least three distinct functions that are each required for FAK tyrosine phosphorylation.
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Affiliation(s)
- Ramon Wade
- Department of Pathology, University of Virginia, P.O. Box 800904, Charlottesville, VA 22908-0904, U.S.A
| | - Scott Vande Pol
- Department of Pathology, University of Virginia, P.O. Box 800904, Charlottesville, VA 22908-0904, U.S.A
- To whom correspondence should be addressed (email )
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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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36
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Jamieson JS, Tumbarello DA, Hallé M, Brown MC, Tremblay ML, Turner CE. Paxillin is essential for PTP-PEST-dependent regulation of cell spreading and motility: a role for paxillin kinase linker. J Cell Sci 2005; 118:5835-47. [PMID: 16317044 DOI: 10.1242/jcs.02693] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The tyrosine phosphatase PTP-PEST has been implicated in the regulation of cell spreading and migration through dephosphorylation of focal adhesion proteins and inhibition of Rac GTPase activity. The focal adhesion adaptor protein paxillin is also necessary for normal cell migration and binds directly to PTP-PEST. In this study, we have utilized PTP-PEST(-/-) and paxillin(-/-) fibroblasts to demonstrate that paxillin is essential for PTP-PEST inhibition of cell spreading and membrane protrusion as well as inhibition of adhesion-induced Rac activation. Furthermore, we show that paxillin-binding is necessary for PTP-PEST stimulation of cell migration. Mutation analysis indicates that PTP-PEST function involves binding to the paxillin C-terminal LIM domains, and signaling through the tyrosine 31 and 118 phosphorylation sites, as well as the LD4 motif of the paxillin N-terminus. Using 'substrate trapping' approaches and immunoprecipitation, we show that the ARF GAP paxillin kinase linker PKL/GIT2, a paxillin LD4 binding partner, is a substrate for PTP-PEST. Additionally, the PKL-paxillin interaction was necessary for PTP-PEST inhibition of cell spreading. These data provide mechanistic insight into how the paxillin-PTP-PEST interaction contributes to integrin signaling events associated with the spatiotemporal regulation of key modulators of the cytoskeleton and cell motility machinery.
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Affiliation(s)
- Jennifer S Jamieson
- Department of Cell and Developmental Biology, State University of New York, Upstate Medical University, Syracuse, NY 13210, USA
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Lai YJ, Chen CS, Lin WC, Lin FT. c-Src-mediated phosphorylation of TRIP6 regulates its function in lysophosphatidic acid-induced cell migration. Mol Cell Biol 2005; 25:5859-68. [PMID: 15988003 PMCID: PMC1168818 DOI: 10.1128/mcb.25.14.5859-5868.2005] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
TRIP6 (thyroid receptor-interacting protein 6), also known as ZRP-1 (zyxin-related protein 1), is a member of the zyxin family that has been implicated in cell motility. Previously we have shown that TRIP6 binds to the LPA2 receptor and associates with several components of focal complexes in an agonist-dependent manner and, thus, enhances lysophosphatidic acid (LPA)-induced cell migration. Here we further report that the function of TRIP6 in LPA signaling is regulated by c-Src-mediated phosphorylation of TRIP6 at the Tyr-55 residue. LPA stimulation induces tyrosine phosphorylation of endogenous TRIP6 in NIH 3T3 cells and c-Src-expressing fibroblasts, which is virtually eliminated in Src-null fibroblasts. Strikingly, both phosphotyrosine-55 and proline-58 residues of TRIP6 are required for Crk binding in vitro and in cells. Mutation of Tyr-55 to Phe does not alter the ability of TRIP6 to localize at focal adhesions or associate with actin. However, it abolishes the association of TRIP6 with Crk and p130cas in cells and significantly reduces the function of TRIP6 to promote LPA-induced ERK activation. Ultimately, these signaling events control TRIP6 function in promoting LPA-induced morphological changes and cell migration.
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Affiliation(s)
- Yun-Ju Lai
- Department of Cell Biology, University of Alabama at Birmingham, Birmingham, AL 35294-0005, USA
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Brown MC, Cary LA, Jamieson JS, Cooper JA, Turner CE. Src and FAK kinases cooperate to phosphorylate paxillin kinase linker, stimulate its focal adhesion localization, and regulate cell spreading and protrusiveness. Mol Biol Cell 2005; 16:4316-28. [PMID: 16000375 PMCID: PMC1196340 DOI: 10.1091/mbc.e05-02-0131] [Citation(s) in RCA: 143] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The ArfGAP paxillin kinase linker (PKL)/G protein-coupled receptor kinase-interacting protein (GIT)2 has been implicated in regulating cell spreading and motility through its transient recruitment of the p21-activated kinase (PAK) to focal adhesions. The Nck-PAK-PIX-PKL protein complex is recruited to focal adhesions by paxillin upon integrin engagement and Rac activation. In this report, we identify tyrosine-phosphorylated PKL as a protein that associates with the SH3-SH2 adaptor Nck, in a Src-dependent manner, after cell adhesion to fibronectin. Both cell adhesion and Rac activation stimulated PKL tyrosine phosphorylation. PKL is phosphorylated on tyrosine residues 286/392/592 by Src and/or FAK and these sites are required for PKL localization to focal adhesions and for paxillin binding. The absence of either FAK or Src-family kinases prevents PKL phosphorylation and suppresses localization of PKL but not GIT1 to focal adhesions after Rac activation. Expression of an activated FAK mutant in the absence of Src-family kinases partially restores PKL localization, suggesting that Src activation of FAK is required for PKL phosphorylation and localization. Overexpression of the nonphosphorylated GFP-PKL Triple YF mutant stimulates cell spreading and protrusiveness, similar to overexpression of a paxillin mutant that does not bind PKL, suggesting that failure to recruit PKL to focal adhesions interferes with normal cell spreading and motility.
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Affiliation(s)
- Michael C Brown
- Department of Cell and Developmental Biology, College of Medicine, State University of New York Upstate Medical University, Syracuse, NY 13210, USA
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Watanabe N, Amano N, Ishizuka H, Mashima K. Leupaxin binds to PEST domain tyrosine phosphatase PEP. Mol Cell Biochem 2005; 269:13-7. [PMID: 15786712 DOI: 10.1007/s11010-005-2149-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PEST domain tyrosine phosphatase (PEP) is an intracellular protein tyrosine phosphatase and characterized by PEST motifs and proline-rich domains in the carboxyl terminal half. PEP is primarily expressed in hematopoietic cells, and together with PEP-binding Csk, may act as a negative regulator of antigen receptor signaling in lymphocytes. Here, we show the binding capability of PEP for leupaxin, which is preferentially expressed in hematopoietic cells and a comparatively new member of the paxillin family characterized by two protein-protein interaction modules, LIM domains and LD motifs. These results suggested that leupaxin might participate in the regulation of the signaling cascade through the binding to PEP in lymphocytes.
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Affiliation(s)
- Noriyuki Watanabe
- Department of Life Science and Frontier Project "Life's Adaptation Strategies to Environmental Changes," Rikkyo (St Paul's) University, Nishi-Ikebukuro, Toshima-ku, Tokyo, Japan
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Abstract
Molecular scaffold or adaptor proteins facilitate precise spatiotemporal regulation and integration of multiple signaling pathways to effect the optimal cellular response to changes in the immediate environment. Paxillin is a multidomain adaptor that recruits both structural and signaling molecules to focal adhesions, sites of integrin engagement with the extracellular matrix, where it performs a critical role in transducing adhesion and growth factor signals to elicit changes in cell migration and gene expression.
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Affiliation(s)
- Michael C Brown
- Dept. of Cell and Developmental Biology, SUNY Upstate Medical University, 750 East Adams Street, Syracuse, NY 13210, USA
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Romanova LY, Hashimoto S, Chay KO, Blagosklonny MV, Sabe H, Mushinski JF. Phosphorylation of paxillin tyrosines 31 and 118 controls polarization and motility of lymphoid cells and is PMA-sensitive. J Cell Sci 2004; 117:3759-68. [PMID: 15252114 DOI: 10.1242/jcs.01206] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Tyrosine phosphorylation of paxillin regulates actin cytoskeleton-dependent changes in cell morphology and motility in adherent cells. In this report we investigated the involvement of paxillin tyrosine phosphorylation in the regulation of actin cytoskeleton-dependent polarization and motility of a non-adherent IL-3-dependent murine pre-B lymphocytic cell line Baf3. We also assessed the effect of phorbol myristate acetate (PMA), a phorbol ester analogous to those currently in clinical trials for the treatment of leukemia, on paxillin phosphorylation. Using tyrosine-to-phenylalanine phosphorylation mutants of paxillin and phosphospecific antibody we demonstrated that IL-3 stimulated phosphorylation of paxillin tyrosine residues 31 and 118, whereas the tyrosines 40 and 181 were constitutively phosphorylated. Phosphorylation of paxillin residues 31 and 118 was required for cell polarization and motility. In the presence of IL-3, PMA dramatically reduced the phosphorylation of residues 31 and 118, which was accompanied by inhibition of cell polarization and motility. This PMA effect was partially recapitulated by expression of exogenous tyrosine 31 and 118 mutants of paxillin. We also demonstrated that PMA inhibited the IL-3-induced and activation-dependent tyrosine phosphorylation of focal adhesion kinase. Thus, our results indicate that phosphorylation of paxillin tyrosine residues 31 and 118 regulates actin-dependent polarization and motility of pre-B Baf3 cells, both of which could be inhibited by PMA. They also suggest that inhibition of upstream signaling by PMA contributes to the decrease of paxillin phosphorylation and subsequent changes in cell morphology.
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Affiliation(s)
- Larisa Y Romanova
- Molecular Genetics Section, Laboratory of Genetics, National Cancer Institute, NIH, 9000 Rockville Pike, Bethesda, MD 20892, USA.
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Cousin H, Alfandari D. A PTP-PEST-like protein affects alpha5beta1-integrin-dependent matrix assembly, cell adhesion, and migration in Xenopus gastrula. Dev Biol 2004; 265:416-32. [PMID: 14732402 DOI: 10.1016/j.ydbio.2003.09.038] [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] [Indexed: 01/17/2023]
Abstract
During amphibian gastrulation, mesodermal cell movements depend on both cell-cell and cell-matrix interactions. Ectodermal cells from the blastocoel roof use alpha5beta1 integrins to assemble a fibronectin-rich extracellular matrix on which mesodermal cells migrate using the same alpha5beta1 integrin. In this report, we show that the tyrosine phosphatase xPTP-PESTr can prevent fibronectin fibril formation when overexpressed in ectodermal cells resulting in delayed gastrulation. In addition, isolated ectodermal cells overexpressing xPTP-PESTr are able to spread on fibronectin using the alpha5beta1 integrin in the absence of activin-A induction and before the onset of gastrulation. We further show that while the inhibition of fibrillogenesis depends on the phosphatase activity of xPTP-PESTr, induction of cell spreading does not. Finally, while cell spreading is usually associated with cell migration, xPTP-PESTr promotes ectodermal cell spreading on fibronectin but also reduces cell migration in response to activin-A, suggesting an adverse effect on cell translocation. We propose that xPTP-PESTr overexpression adversely affect cell migration by preventing de-adhesion of cells from the substrate.
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Affiliation(s)
- Hélène Cousin
- Paige Laboratory, Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA 01003, USA
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Larsen M, Tremblay ML, Yamada KM. Phosphatases in cell–matrix adhesion and migration. Nat Rev Mol Cell Biol 2003; 4:700-11. [PMID: 14506473 DOI: 10.1038/nrm1199] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Many proteins that have been implicated in cell-matrix adhesion and cell migration are phosphorylated, which regulates their folding, enzymatic activities and protein-protein interactions. Although modulation of cell motility by kinases is well known, increasing evidence confirms that phosphatases are essential at each stage of the migration process. Phosphatases can control the formation and maintenance of the actin cytoskeleton, regulate small GTPase molecular switches, and modulate the dynamics of matrix-adhesion interaction, actin contraction, rear release and migratory directionality.
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Affiliation(s)
- Melinda Larsen
- Craniofacial Developmental Biology and Regeneration Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Building 30/Room 421, 30 Convent Drive, MSC 4370, Bethesda, Maryland 20892-4370, USA.
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44
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Johnson G, Moore SW. Human acetylcholinesterase binds to mouse laminin-1 and human collagen IV by an electrostatic mechanism at the peripheral anionic site. Neurosci Lett 2003; 337:37-40. [PMID: 12524166 DOI: 10.1016/s0304-3940(02)01298-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Acetylcholinesterase (EC 3.1.1.7; AChE) is known to induce neurite outgrowth and differentiation, but its ligands are as yet unknown. Laminin-1 and collagen IV were investigated as potential ligands for AChE. We observed specific saturable binding of biotinylated human AChE to mouse laminin and human collagen, with K(d) values of 4.9482 nM (SE 0.3145 nM) and 1.1617 nM (SE 0.1921 nM) respectively. Peripheral anionic site inhibitors (fasciculin, BW284c51, propidium and gallamine) also significantly reduced binding with fasciculin being the most effective. Significant reductions in AChE-laminin and AChE-collagen interactions were produced by a monoclonal anti-AChE antibody known to react with the peripheral anionic site, and a partial reduction with an antibody that partially recognises the site. Self-association of AChE was also observed (K(d)=16.3235 nM; SE 5.8120 nM); increasing markedly at low pH, but not significantly affected by either inhibitors or antibodies, suggesting a non-specific aggregation phenomenon. Binding to laminin and collagen was significantly reduced by increasing ionic strength and decreasing pH, indicating a dominant role for electrostatic interactions, and suggesting that the site may be different from the hydrophobic site identified for the AChE-amyloid interaction.
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Affiliation(s)
- Glynis Johnson
- Department of Pediatric Surgery, University of Stellenbosch, Faculty of Health Sciences, Tygerberg, South Africa.
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45
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Aberrant activation of focal adhesion proteins mediates fibrillar amyloid beta-induced neuronal dystrophy. J Neurosci 2003. [PMID: 12533609 DOI: 10.1523/jneurosci.23-02-00493.2003] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Neuronal dystrophy is a pathological hallmark of Alzheimer's disease (AD) that is not observed in other neurodegenerative disorders that lack amyloid deposition. Treatment of cortical neurons with fibrillar amyloid beta (Abeta) peptides induces progressive neuritic dystrophy accompanied by a marked loss of synaptophysin immunoreactivity (Grace et al., 2002). Here, we report that fibrillar Abeta-induced neuronal dystrophy is mediated by the activation of focal adhesion (FA) proteins and the formation of aberrant FA structures adjacent to Abeta deposits. In the AD brain, activated FA proteins are observed associated with the majority of senile plaques. Clustered integrin receptors and activated paxillin (phosphorylated at Tyr-31) and focal adhesion kinase (phosphorylated at Tyr-297) are mainly detected in dystrophic neurites surrounding Abeta plaque cores, where they colocalize with hyperphosphorylated tau. Deletion experiments demonstrated that the presence of the LIM domains in the paxillin C terminus and the recruitment of the protein-Tyr phosphatase (PTP)-PEST to the FA complex are required for Abeta-induced neuronal dystrophy. Therefore, both paxillin and PTP-PEST appear to be critical elements in the generation of the dystrophic response. Paxillin is a scaffolding protein to which other FA proteins bind, leading to the formation of the FA contact and initiation of signaling cascades. PTP-PEST plays a key role in the dynamic regulation of focal adhesion contacts in response to extracellular cues. Thus, in the AD brain, fibrillar Abeta may induce neuronal dystrophy by triggering a maladaptive plastic response mediated by FA protein activation and tau hyperphosphorylation.
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46
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Côté JF, Vuori K. Identification of an evolutionarily conserved superfamily of DOCK180-related proteins with guanine nucleotide exchange activity. J Cell Sci 2002; 115:4901-13. [PMID: 12432077 DOI: 10.1242/jcs.00219] [Citation(s) in RCA: 321] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Mammalian DOCK180 protein and its orthologues Myoblast City (MBC) and CED-5 in Drosophila and Caenorhabditis elegans, respectively, function as critical regulators of the small GTPase Rac during several fundamentally important biological processes, such as cell motility and phagocytosis. The mechanism by which DOCK180 and its orthologues regulate Rac has remained elusive. We report here the identification of a domain within DOCK180 named DHR-2 (Dock Homology Region-2) that specifically binds to nucleotide-free Rac and activates Rac in vitro. Our studies further demonstrate that the DHR-2 domain is both necessary and sufficient for DOCK180-mediated Rac activation in vivo. Importantly, we have identified several novel homologues of DOCK180 that possess this domain and found that many of them directly bind to and exchange GDP for GTP both in vitro and in vivo on either Rac or another Rho-family member, Cdc42. Our studies therefore identify a novel protein domain that interacts with and activates GTPases and suggest the presence of an evolutionarily conserved DOCK180-related superfamily of exchange factors.
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Affiliation(s)
- Jean-François Côté
- The Burnham Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
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Sastry SK, Lyons PD, Schaller MD, Burridge K. PTP-PEST controls motility through regulation of Rac1. J Cell Sci 2002; 115:4305-16. [PMID: 12376562 DOI: 10.1242/jcs.00105] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The cytoplasmic protein tyrosine phosphatase, PTP-PEST, associates with the focal adhesion proteins p130cas and paxillin and has recently been implicated in cell migration. In this study, we investigated the mechanism by which PTP-PEST regulates this phenomenon. We find that PTP-PEST is activated in an adhesion-dependent manner and localizes to the tips of membrane protrusions in spreading fibroblasts. We show that the catalytic activity of PTP-PEST is a key determinant for its effects on motility. Overexpression of PTP-PEST, but not a catalytically inactive form, impairs haptotaxis, cell spreading and formation of membrane protrusions in CHOK1 cells. In addition, overexpression of PTP-PEST in Rat1 fibroblasts perturbs membrane ruffling and motility in response to PDGF stimulation. The expression level of PTP-PEST modulates the activity of the small GTPase, Rac1. PTP-PEST overexpression suppresses activation of Rac1 in response to both integrin-mediated adhesion or growth factor stimulation. In contrast, fibroblasts that lack PTP-PEST expression show enhanced Rac1 activity. Co-expression of constitutively active Rac1 with PTP-PEST overcomes the inhibition of cell spreading and migration indicating that PTP-PEST acts by antagonizing Rac1 activation. Our data suggest a model in which PTP-PEST is activated by integrins and localized to regions where it can control motile events at the leading edge through inhibition of the small GTPase Rac1.
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Affiliation(s)
- Sarita K Sastry
- Department of Cell and Developmental Biology and Lineberger Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA.
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48
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Abstract
The alpha4 integrins (alpha4beta1 and alpha4beta7) play multiple roles in the immune system. Alpha4 integrins impact hematopoiesis, leukocyte trafficking in immune surveillance and inflammation, and leukocyte activation and survival. To perform these functions, alpha4 integrins act as both adhesive and signaling receptors. Paxillin, a signaling adapter molecule, binds directly to the alpha4 subunit cytoplasmic domain, and its binding is regulated by serine phosphorylation of the alpha4 subunit. This regulated interaction of paxillin with the alpha4 subunit is likely to regulate the diverse functions of alpha4 integrins in the immune system. Furthermore, this protein-protein interaction may provide novel targets for the modulation of the immune response.
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Affiliation(s)
- David M Rose
- Division of Rheumatology, Allergy, and Immunology, Department of Medicine, The University of California, San Diego, California, USA
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Brown MC, Turner CE. Roles for the tubulin- and PTP-PEST-binding paxillin LIM domains in cell adhesion and motility. Int J Biochem Cell Biol 2002; 34:855-63. [PMID: 11950600 DOI: 10.1016/s1357-2725(01)00154-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cell dynamics mediated through cell-extracellular matrix contacts, such as adhesion and motility involve the precise regulation of large complexes of structural and signaling molecules called focal adhesions (FAs). Paxillin is a multi-domain FA adaptor protein containing five amino-terminal paxillin leucine-aspartate repeat (LD) motifs and four carboxyl-terminal Lin-11 Isl-1 and Mec-3 (LIM) domains. The LD motifs support paxillin binding to actopaxin, integrin linked kinase (ILK), FA kinase (FAK), paxillin kinase linker (PKL) and vinculin. Of the LIM domains, LIM2 and 3 comprise the paxillin FA-targeting motif, with phosphorylation of these domains modulating paxillin targeting and cell adhesion to fibronectin (Fn). The identity of the paxillin FA targeting partner remains to be determined; however, the LIM domains mediate interactions with tubulin and the protein-tyrosine phosphatase (PTP)-PEST. PTP-PEST binding requires both LIM3 and 4, whereas, the precise LIM target of tubulin binding is not known. In this report, we demonstrate that the individual paxillin LIM2 and 3 domains support specific binding to tubulin and suggest a potential role for this interaction in the regulation of paxillin sub-cellular compartmentalization. In addition, expression of paxillin molecules with mutations in the tubulin- and PTP-PEST-binding LIM domains differentially impaired Chinese hamster ovary K1 (CHO.K1) cell adhesion and migration to Fn. Perturbation of LIM3 or 4 inhibited adhesion while mutation of LIM2 or 4 decreased cell motility. Interestingly, expression of tandem LIM2-3 inhibited cell adhesion and spreading while LIM3-4 stimulated a well-spread polarized phenotype. These data offer further support for a critical role for paxillin in cell adhesion and motility.
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Affiliation(s)
- Michael C Brown
- Department of Cell & Developmental Biology, State University of New York Upstate Medical University, 750 East Adams Street Syracuse, New York, NY 13210-2306, USA.
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50
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Liu S, Kiosses WB, Rose DM, Slepak M, Salgia R, Griffin JD, Turner CE, Schwartz MA, Ginsberg MH. A fragment of paxillin binds the alpha 4 integrin cytoplasmic domain (tail) and selectively inhibits alpha 4-mediated cell migration. J Biol Chem 2002; 277:20887-94. [PMID: 11919182 DOI: 10.1074/jbc.m110928200] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The alpha(4) integrins play important roles in embryogenesis, hematopoiesis, cardiac development, and the immune responses. The alpha(4) integrin subunit is indispensable for these biological processes, possibly because the alpha(4) subunit regulates cellular functions differently from other integrin alpha subunits. We have previously reported that the alpha(4) cytoplasmic domain directly and tightly binds paxillin, an intracellular signaling adaptor molecule, and this interaction accounts for some of the unusual functional responses to alpha(4) integrin-mediated cell adhesion. We also have identified a conserved 9-amino acid region (Glu(983)-Tyr(991)) in the alpha(4) cytoplasmic domain that is sufficient for paxillin binding, and an alanine substitution at either Glu(983) or Tyr(991) within this region disrupted the alpha(4)-paxillin interaction and reversed the effects of the alpha(4) cytoplasmic domain on cell spreading and migration. In the current study, we have mapped the alpha(4)-binding site within paxillin using mutational analysis, and examined its effects on the alpha(4) tail-mediated functional responses. Here we report that sequences between residues Ala(176) and Asp(275) of paxillin are sufficient for binding to the alpha(4) tail. We found that the alpha(4) tail, paxillin, and FAT, the focal adhesion targeting domain of pp125(FAK), could form a ternary complex and that the alpha(4)-binding paxillin fragment, P(Ala(176)-Asp(275)), specifically blocked paxillin binding to the alpha(4) tail more efficiently than it blocked binding to FAT. Furthermore, when expressed in cells, this alpha(4)-binding paxillin fragment specifically inhibited the alpha(4) tail-stimulated cell migration. Thus, paxillin binding to the alpha(4) tail leads to enhanced cell migration and inhibition of the alpha(4)-paxillin interaction selectively blocks the alpha4-dependent cellular responses.
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Affiliation(s)
- Shouchun Liu
- Department of Vascular Biology and Cell Biology, The Scripps Research Institute, La Jolla, California 92037, USA.
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