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Kumar S, Stainer A, Dubrulle J, Simpkins C, Cooper JA. Cas phosphorylation regulates focal adhesion assembly. eLife 2023; 12:e90234. [PMID: 37489578 PMCID: PMC10435235 DOI: 10.7554/elife.90234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 07/19/2023] [Indexed: 07/26/2023] Open
Abstract
Integrin-mediated cell attachment rapidly induces tyrosine kinase signaling. Despite years of research, the role of this signaling in integrin activation and focal adhesion assembly is unclear. We provide evidence that the Src-family kinase (SFK) substrate Cas (Crk-associated substrate, p130Cas, BCAR1) is phosphorylated and associated with its Crk/CrkL effectors in clusters that are precursors of focal adhesions. The initial phospho-Cas clusters contain integrin β1 in its inactive, bent closed, conformation. Later, phospho-Cas and total Cas levels decrease as integrin β1 is activated and core focal adhesion proteins including vinculin, talin, kindlin, and paxillin are recruited. Cas is required for cell spreading and focal adhesion assembly in epithelial and fibroblast cells on collagen and fibronectin. Cas cluster formation requires Cas, Crk/CrkL, SFKs, and Rac1 but not vinculin. Rac1 provides positive feedback onto Cas through reactive oxygen, opposed by negative feedback from the ubiquitin proteasome system. The results suggest a two-step model for focal adhesion assembly in which clusters of phospho-Cas, effectors and inactive integrin β1 grow through positive feedback prior to integrin activation and recruitment of core focal adhesion proteins.
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Affiliation(s)
- Saurav Kumar
- Fred Hutchinson Cancer CenterSeattleUnited States
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2
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Jimi E, Honda H, Nakamura I. The unique function of p130Cas in regulating the bone metabolism. Pharmacol Ther 2021; 230:107965. [PMID: 34391790 DOI: 10.1016/j.pharmthera.2021.107965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 07/20/2021] [Indexed: 11/19/2022]
Abstract
p130 Crk-associated substrate (Cas) functions as an adapter protein and plays important roles in certain cell functions, such as cell proliferation, spreading, migration, and invasion. Furthermore, it has recently been reported to have a new function as a mechanosensor. Since bone is a tissue that is constantly under gravity, it is exposed to mechanical stress. Mechanical unloading, such as in a microgravity environment in space or during bed rest, leads to a decrease in bone mass because of the suppression of bone formation and the stimulation of bone resorption. Osteoclasts are multinucleated bone-resorbing giant cells that recognize bone and then form a ruffled border in the resorption lacuna. p130Cas is a molecule located downstream of c-Src that is important for the formation of a ruffled border in osteoclasts. Indeed, osteoclast-specific p130Cas-deficient mice exhibit osteopetrosis due to osteoclast dysfunction, similar to c-Src-deficient mice. Osteoblasts subjected to mechanical stress induce both the phosphorylation of p130Cas and osteoblast differentiation. In osteocytes, mechanical stress regulates bone mass by shuttling p130Cas between the cytoplasm and nucleus. Oral squamous cell carcinoma (OSCC) cells express p130Cas more strongly than epithelial cells in normal tissues. The knockdown of p130Cas in OSCC cells suppressed the cell growth, the expression of receptor activator of NF-κB ligand, which induces osteoclast formation, and bone invasion by OSCC. Taken together, these findings suggest that p130Cas might be a novel therapeutic target molecule in bone diseases, such as osteoporosis, rheumatoid arthritis, bone loss due to bed rest, and bone invasion and metastasis of cancer.
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Affiliation(s)
- Eijiro Jimi
- Oral Health/Brain Health/Total Health Research Center, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan; Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
| | - Hiroaki Honda
- Field of Human Disease Models, Major in Advanced Life Sciences and Medicine, Institute of Laboratory Animals, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan
| | - Ichiro Nakamura
- Department of Rehabilitation, Yugawara Hospital, Japan Community Health Care Organization, 2-21-6 Chuo, Yugawara, Ashigara-shimo, Kanagawa 259-0396, Japan
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3
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Steenkiste EM, Berndt JD, Pilling C, Simpkins C, Cooper JA. A Cas-BCAR3 co-regulatory circuit controls lamellipodia dynamics. eLife 2021; 10:67078. [PMID: 34169835 PMCID: PMC8266394 DOI: 10.7554/elife.67078] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 06/21/2021] [Indexed: 11/13/2022] Open
Abstract
Integrin adhesion complexes regulate cytoskeletal dynamics during cell migration. Adhesion activates phosphorylation of integrin-associated signaling proteins, including Cas (p130Cas, BCAR1), by Src-family kinases. Cas regulates leading-edge protrusion and migration in cooperation with its binding partner, BCAR3. However, it has been unclear how Cas and BCAR3 cooperate. Here, using normal epithelial cells, we find that BCAR3 localization to integrin adhesions requires Cas. In return, Cas phosphorylation, as well as lamellipodia dynamics and cell migration, requires BCAR3. These functions require the BCAR3 SH2 domain and a specific phosphorylation site, Tyr 117, that is also required for BCAR3 downregulation by the ubiquitin-proteasome system. These findings place BCAR3 in a co-regulatory positive-feedback circuit with Cas, with BCAR3 requiring Cas for localization and Cas requiring BCAR3 for activation and downstream signaling. The use of a single phosphorylation site in BCAR3 for activation and degradation ensures reliable negative feedback by the ubiquitin-proteasome system.
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Affiliation(s)
- Elizabeth M Steenkiste
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, United States.,Molecular and Cellular Biology Program, University of Washington, Seattle, United States
| | - Jason D Berndt
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, United States
| | - Carissa Pilling
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, United States.,Molecular and Cellular Biology Program, University of Washington, Seattle, United States
| | - Christopher Simpkins
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, United States
| | - Jonathan A Cooper
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, United States.,Molecular and Cellular Biology Program, University of Washington, Seattle, United States
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4
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Linklater ES, Duncan ED, Han KJ, Kaupinis A, Valius M, Lyons TR, Prekeris R. Rab40-Cullin5 complex regulates EPLIN and actin cytoskeleton dynamics during cell migration. J Cell Biol 2021; 220:212111. [PMID: 33999101 PMCID: PMC8129794 DOI: 10.1083/jcb.202008060] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 02/09/2021] [Accepted: 04/26/2021] [Indexed: 12/12/2022] Open
Abstract
Rab40b is a SOCS box–containing protein that regulates the secretion of MMPs to facilitate extracellular matrix remodeling during cell migration. Here, we show that Rab40b interacts with Cullin5 via the Rab40b SOCS domain. We demonstrate that loss of Rab40b–Cullin5 binding decreases cell motility and invasive potential and show that defective cell migration and invasion stem from alteration to the actin cytoskeleton, leading to decreased invadopodia formation, decreased actin dynamics at the leading edge, and an increase in stress fibers. We also show that these stress fibers anchor at less dynamic, more stable focal adhesions. Mechanistically, changes in the cytoskeleton and focal adhesion dynamics are mediated in part by EPLIN, which we demonstrate to be a binding partner of Rab40b and a target for Rab40b–Cullin5-dependent localized ubiquitylation and degradation. Thus, we propose a model where Rab40b–Cullin5-dependent ubiquitylation regulates EPLIN localization to promote cell migration and invasion by altering focal adhesion and cytoskeletal dynamics.
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Affiliation(s)
- Erik S Linklater
- Department of Cell and Developmental Biology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Emily D Duncan
- Department of Cell and Developmental Biology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Ke-Jun Han
- Department of Cell and Developmental Biology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Algirdas Kaupinis
- Proteomics Center, Institute of Biochemistry, Vilnius University Life Sciences Center, Vilnius, Lithuania
| | - Mindaugas Valius
- Proteomics Center, Institute of Biochemistry, Vilnius University Life Sciences Center, Vilnius, Lithuania
| | - Traci R Lyons
- Division of Medical Oncology, Department of Medicine, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO.,University of Colorado Cancer Center, Young Women's Breast Cancer Translational Program, Aurora, CO
| | - Rytis Prekeris
- Department of Cell and Developmental Biology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
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5
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Park T, Large N, Curran T. Quantitative assessment of glioblastoma phenotypes in vitro establishes cell migration as a robust readout of Crk and CrkL activity. J Biol Chem 2021; 296:100390. [PMID: 33561443 PMCID: PMC7961105 DOI: 10.1016/j.jbc.2021.100390] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 02/01/2021] [Accepted: 02/04/2021] [Indexed: 02/03/2023] Open
Abstract
The expression levels of CT10 regulator of kinase (Crk) and Crk-like (CrkL) are elevated in many human cancers, including glioblastoma (GBM), and are believed to contribute to poor prognosis. Although Crk and CrkL have been proposed as therapeutic targets in these tumors, the lack of a reliable, quantitative assay to measure Crk and CrkL activity has hindered development of inhibitors. Here, we knocked down Crk, CrkL, or both using siRNAs in a human GBM cell line, U-118MG, to determine the respective, quantitative contributions of Crk and CrkL to cellular phenotypes. The combined use of specific and potent Crk and CrkL siRNAs induced effective knockdown of CrkII, CrkI, and CrkL. Whereas Crk knockdown did not affect cell morphology, proliferation, adhesion, or invasion, CrkL knockdown caused shrinkage of cells and inhibition of cell proliferation, adhesion, and invasion. Crk/CrkL double knockdown resulted in more pronounced morphological alterations and more robust inhibition of proliferation, adhesion, and invasion. Furthermore, Crk/CrkL double knockdown completely blocked cell migration, and this effect was rescued by transient overexpression of CrkL but not of Crk. Quantification of protein levels indicated that CrkL is expressed more abundantly than CrkII and CrkI in U-118MG cells. These results demonstrate both the predominant role of CrkL and the essential overlapping functions of Crk and CrkL in U-118MG cells. Furthermore, our study indicates that migration of U-118MG cells depends entirely on Crk and CrkL. Thus, impedance-based, real-time measurement of tumor cell migration represents a robust assay for monitoring Crk and CrkL activities.
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Affiliation(s)
- Taeju Park
- Children's Mercy Research Institute, Children's Mercy Kansas City, Kansas City, Missouri, USA; Department of Pediatrics, University of Missouri-Kansas City School of Medicine, Kansas City, Missouri, USA.
| | - Neka Large
- Children's Mercy Research Institute, Children's Mercy Kansas City, Kansas City, Missouri, USA
| | - Tom Curran
- Children's Mercy Research Institute, Children's Mercy Kansas City, Kansas City, Missouri, USA; Department of Pediatrics, University of Missouri-Kansas City School of Medicine, Kansas City, Missouri, USA
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6
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Actin polymerization downstream of integrins: signaling pathways and mechanotransduction. Biochem J 2020; 477:1-21. [PMID: 31913455 DOI: 10.1042/bcj20170719] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 11/17/2019] [Accepted: 12/16/2019] [Indexed: 01/04/2023]
Abstract
A cell constantly adapts to its environment. Cell decisions to survive, to proliferate or to migrate are dictated not only by soluble growth factors, but also through the direct interaction of the cell with the surrounding extracellular matrix (ECM). Integrins and their connections to the actin cytoskeleton are crucial for monitoring cell attachment and the physical properties of the substratum. Cell adhesion dynamics are modulated in complex ways by the polymerization of branched and linear actin arrays, which in turn reinforce ECM-cytoskeleton connection. This review describes the major actin regulators, Ena/VASP proteins, formins and Arp2/3 complexes, in the context of signaling pathways downstream of integrins. We focus on the specific signaling pathways that transduce the rigidity of the substrate and which control durotaxis, i.e. directed migration of cells towards increased ECM rigidity. By doing so, we highlight several recent findings on mechanotransduction and put them into a broad integrative perspective that is the result of decades of intense research on the actin cytoskeleton and its regulation.
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7
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Santoro R, Perrucci GL, Gowran A, Pompilio G. Unchain My Heart: Integrins at the Basis of iPSC Cardiomyocyte Differentiation. Stem Cells Int 2019; 2019:8203950. [PMID: 30906328 PMCID: PMC6393933 DOI: 10.1155/2019/8203950] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 12/20/2018] [Accepted: 01/10/2019] [Indexed: 02/06/2023] Open
Abstract
The cellular response to the extracellular matrix (ECM) microenvironment mediated by integrin adhesion is of fundamental importance, in both developmental and pathological processes. In particular, mechanotransduction is of growing importance in groundbreaking cellular models such as induced pluripotent stem cells (iPSC), since this process may strongly influence cell fate and, thus, augment the precision of differentiation into specific cell types, e.g., cardiomyocytes. The decryption of the cellular machinery starting from ECM sensing to iPSC differentiation calls for new in vitro methods. Conveniently, engineered biomaterials activating controlled integrin-mediated responses through chemical, physical, and geometrical designs are key to resolving this issue and could foster clinical translation of optimized iPSC-based technology. This review introduces the main integrin-dependent mechanisms and signalling pathways involved in mechanotransduction. Special consideration is given to the integrin-iPSC linkage signalling chain in the cardiovascular field, focusing on biomaterial-based in vitro models to evaluate the relevance of this process in iPSC differentiation into cardiomyocytes.
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Affiliation(s)
- Rosaria Santoro
- Unità di Biologia Vascolare e Medicina Rigenerativa, Centro Cardiologico Monzino IRCCS, via Carlo Parea 4, Milan, Italy
| | - Gianluca Lorenzo Perrucci
- Unità di Biologia Vascolare e Medicina Rigenerativa, Centro Cardiologico Monzino IRCCS, via Carlo Parea 4, Milan, Italy
| | - Aoife Gowran
- Unità di Biologia Vascolare e Medicina Rigenerativa, Centro Cardiologico Monzino IRCCS, via Carlo Parea 4, Milan, Italy
| | - Giulio Pompilio
- Unità di Biologia Vascolare e Medicina Rigenerativa, Centro Cardiologico Monzino IRCCS, via Carlo Parea 4, Milan, Italy
- Dipartimento di Scienze Cliniche e di Comunità, Università degli Studi di Milano, via Festa del Perdono 7, Milan, Italy
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8
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Nichols AEC, Settlage RE, Werre SR, Dahlgren LA. Novel roles for scleraxis in regulating adult tenocyte function. BMC Cell Biol 2018; 19:14. [PMID: 30086712 PMCID: PMC6081934 DOI: 10.1186/s12860-018-0166-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 07/30/2018] [Indexed: 12/15/2022] Open
Abstract
Background Tendinopathies are common and difficult to resolve due to the formation of scar tissue that reduces the mechanical integrity of the tissue, leading to frequent reinjury. Tenocytes respond to both excessive loading and unloading by producing pro-inflammatory mediators, suggesting that these cells are actively involved in the development of tendon degeneration. The transcription factor scleraxis (Scx) is required for the development of force-transmitting tendon during development and for mechanically stimulated tenogenesis of stem cells, but its function in adult tenocytes is less well-defined. The aim of this study was to further define the role of Scx in mediating the adult tenocyte mechanoresponse. Results Equine tenocytes exposed to siRNA targeting Scx or a control siRNA were maintained under cyclic mechanical strain before being submitted for RNA-seq analysis. Focal adhesions and extracellular matrix-receptor interaction were among the top gene networks downregulated in Scx knockdown tenocytes. Correspondingly, tenocytes exposed to Scx siRNA were significantly softer, with longer vinculin-containing focal adhesions, and an impaired ability to migrate on soft surfaces. Other pathways affected by Scx knockdown included increased oxidative phosphorylation and diseases caused by endoplasmic reticular stress, pointing to a larger role for Scx in maintaining tenocyte homeostasis. Conclusions Our study identifies several novel roles for Scx in adult tenocytes, which suggest that Scx facilitates mechanosensing by regulating the expression of several mechanosensitive focal adhesion proteins. Furthermore, we identified a number of other pathways and targets affected by Scx knockdown that have the potential to elucidate the role that tenocytes may play in the development of degenerative tendinopathy. Electronic supplementary material The online version of this article (10.1186/s12860-018-0166-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Anne E C Nichols
- Department of Large Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, 205 Duck Pond Drive, Blacksburg, VA, 24061-0442, USA
| | - Robert E Settlage
- Advanced Research Computing, Virginia Biocomplexity Institute, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Stephen R Werre
- Laboratory for Study Design and Statistical Analysis, Virginia-Maryland College of Veterinary Medicine, Blacksburg, VA, 24061, USA
| | - Linda A Dahlgren
- Department of Large Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, 205 Duck Pond Drive, Blacksburg, VA, 24061-0442, USA.
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9
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Teckchandani A, Cooper JA. The ubiquitin-proteasome system regulates focal adhesions at the leading edge of migrating cells. eLife 2016; 5. [PMID: 27656905 PMCID: PMC5092051 DOI: 10.7554/elife.17440] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Accepted: 09/21/2016] [Indexed: 02/06/2023] Open
Abstract
Cell migration requires the cyclical assembly and disassembly of focal adhesions. Adhesion induces phosphorylation of focal adhesion proteins, including Cas (Crk-associated substrate/p130Cas/BCAR1). However, Cas phosphorylation stimulates adhesion turnover. This raises the question of how adhesion assembly occurs against opposition from phospho-Cas. Here we show that suppressor of cytokine signaling 6 (SOCS6) and Cullin 5, two components of the CRL5SOCS6 ubiquitin ligase, inhibit Cas-dependent focal adhesion turnover at the front but not rear of migrating epithelial cells. The front focal adhesions contain phospho-Cas which recruits SOCS6. If SOCS6 cannot access focal adhesions, or if cullins or the proteasome are inhibited, adhesion disassembly is stimulated. This suggests that the localized targeting of phospho-Cas within adhesions by CRL5SOCS6 and concurrent cullin and proteasome activity provide a negative feedback loop, ensuring that adhesion assembly predominates over disassembly at the leading edge. By this mechanism, ubiquitination provides a new level of spatio-temporal control over cell migration. DOI:http://dx.doi.org/10.7554/eLife.17440.001 Animal cells can move in the body, for example to heal a wound, by protruding a leading edge forwards, attaching it to the surroundings and then pulling against these new attachments while disassembling the older ones. Mechanical forces regulate the assembly and disassembly of these attachments, known as focal adhesions, and so do signals from outside the cell that are transmitted to the adhesions via specialized proteins. However, it was not clear how the assembly and disassembly of adhesions is coordinated. CRL5 is a ubiquitin ligase, an enzyme that can mark other proteins for destruction. Cells migrate more quickly if CRL5 is inhibited, and so Teckchandani and Cooper set out to uncover whether CRL5 affects the assembly and disassembly of focal adhesions. The experiments showed that human cells lacking a crucial component of the CRL5 complex, SOCS6, disassemble adhesions faster than normal cells, but only at their leading edge and not at the rear. Teckchandani and Cooper also found that SOCS6 localizes to the leading edge by binding to a focal adhesion protein called Cas. Shortly after the attachments assemble, the Cas protein becomes tagged with a phosphate group and then acts to promote the adhesion to disassemble. Further experiments indicated that Cas was marked by the CRL5 complex and possibly destroyed while in or very close to the leading edge adhesions, slowing their disassembly. Together, these findings suggest that by binding Cas, SOCS6 regulates the turnover of adhesions, specifically by inhibiting disassembly and allowing adhesions to grow at the leading edge. Since SOCS6 is not present in adhesions outside of the leading edge, this may help explain how the older adhesions are disassembled. Future studies could next focus on the exact sequence of events that occur in focal adhesions after the CRL5 complex binds to Cas as the cell migrates. DOI:http://dx.doi.org/10.7554/eLife.17440.002
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Affiliation(s)
- Anjali Teckchandani
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, United States
| | - Jonathan A Cooper
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, United States
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10
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Chojnacka K, Mruk DD. The Src non-receptor tyrosine kinase paradigm: New insights into mammalian Sertoli cell biology. Mol Cell Endocrinol 2015; 415:133-42. [PMID: 26296907 DOI: 10.1016/j.mce.2015.08.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 07/27/2015] [Accepted: 08/09/2015] [Indexed: 11/23/2022]
Abstract
Src kinases are non-receptor tyrosine kinases that phosphorylate diverse substrates, which control processes such as cell proliferation, differentiation and survival; cell adhesion; and cell motility. c-Src, the prototypical member of this protein family, is widely expressed by several organs that include the testis. In the seminiferous epithelium of the adult rat testis, c-Src is highest at the tubule lumen during the release of mature spermatids. Other studies show that testosterone regulates spermatid adhesion to Sertoli cells via c-Src, indicating Src phosphorylates key substrates that prompt the disassembly of Sertoli cell-spermatid junctions. A more recent in vitro study reveals that c-Src participates in the internalization of proteins that constitute the blood-testis barrier, which is present between Sertoli cells, suggesting a similar mechanism of junction disassembly is at play during spermiation. In this review, we discuss recent findings on c-Src, with an emphasis on its role in spermatogenesis in the mammalian testis.
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Affiliation(s)
| | - Dolores D Mruk
- Center for Biomedical Research, Population Council, New York, USA.
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11
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Janoštiak R, Pataki AC, Brábek J, Rösel D. Mechanosensors in integrin signaling: The emerging role of p130Cas. Eur J Cell Biol 2014; 93:445-54. [DOI: 10.1016/j.ejcb.2014.07.002] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 06/11/2014] [Accepted: 07/01/2014] [Indexed: 12/17/2022] Open
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Rajendran V, Sethumadhavan R, Purohit R. Investigation of binding phenomenon of NSP3 and p130Cas mutants and their effect on cell signalling. Cell Biochem Biophys 2014; 67:623-33. [PMID: 23494262 DOI: 10.1007/s12013-013-9551-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Members of the novel SH2-containing protein (NSP3) and Crk-associated substrate (p130Cas) protein families form a multi-domain signalling platforms that mediate cell signalling process. We analysed the damaging consequences of three mutations, each from NSP3 (NSP3(L469R), NSP3(L623E), NSP3(R627E)) and p130Cas (p130Cas(F794R), p130Cas(L787E), p130Cas(D797R)) protein with respect to their native biological partners. Mutations depicted notable loss in interaction affinity towards their corresponding biological partners. NSP3(L469R) and p130Cas(D797R) mutations were predicted as most prominent in docking analysis. Molecular dynamics (MD) studies were conducted to evaluate structural consequences of most prominent mutation in NSP3 and p130Cas obtained from the docking analysis. MD analysis confirmed that mutation in NSP3(L469R) and p130Cas(D797R) showed significant structural deviation, changes in conformations and increased flexibility, which in turn affected the binding affinity with their biological partners. Moreover, the root mean square fluctuation has indicated a rise in fluctuation of residues involved in moderate interaction acquired between the NSP3 and p130Cas. It has significantly affected the binding interaction in mutant complexes. The results obtained in this work present a detailed overview of molecular mechanisms involved in the loss of cell signalling associated with NSP3 and p130Cas protein.
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13
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Giridharan SSP, Caplan S. MICAL-family proteins: Complex regulators of the actin cytoskeleton. Antioxid Redox Signal 2014; 20:2059-73. [PMID: 23834433 PMCID: PMC3993057 DOI: 10.1089/ars.2013.5487] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
SIGNIFICANCE The molecules interacting with CasL (MICAL) family members participate in a multitude of activities, including axonal growth cone repulsion, membrane trafficking, apoptosis, and bristle development in flies. An interesting feature of MICAL proteins is the presence of an N-terminal flavo-mono-oxygenase domain. This mono-oxygenase domain generates redox potential with which MICALs can either oxidize proteins or produce reactive oxygen species (ROS). Actin is one such protein that is affected by MICAL function, leading to dramatic cytoskeletal rearrangements. This review describes the MICAL-family members, and discusses their mechanisms of actin-binding and regulation of actin cytoskeleton organization. RECENT ADVANCES Recent studies show that MICALs directly induce oxidation of actin molecules, leading to actin depolymerization. ROS production by MICALs also causes oxidation of collapsin response mediator protein-2, a microtubule assembly promoter, which subsequently undergoes phosphorylation. CRITICAL ISSUES MICAL proteins oxidize proteins through two mechanisms: either directly by oxidizing methionine residues or indirectly via the production of ROS. It remains unclear whether MICAL proteins employ both mechanisms or whether the activity of MICAL-family proteins might vary with different substrates. FUTURE DIRECTIONS The identification of additional substrates oxidized by MICAL will shed new light on MICAL protein function. Additional directions include expanding studies toward the MICAL-like homologs that lack flavin adenine dinucleotide domains and oxidation activity.
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Affiliation(s)
- Sai Srinivas Panapakkam Giridharan
- Department of Biochemistry and Molecular Biology, and the Pamela and Fred Buffett Cancer Center, University of Nebraska Medical Center , Omaha, Nebraska
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14
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Gonsior C, Binamé F, Frühbeis C, Bauer NM, Hoch-Kraft P, Luhmann HJ, Trotter J, White R. Oligodendroglial p130Cas is a target of Fyn kinase involved in process formation, cell migration and survival. PLoS One 2014; 9:e89423. [PMID: 24586768 PMCID: PMC3931761 DOI: 10.1371/journal.pone.0089423] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 01/21/2014] [Indexed: 01/06/2023] Open
Abstract
Oligodendrocytes are the myelinating glial cells of the central nervous system. In the course of brain development, oligodendrocyte precursor cells migrate, scan the environment and differentiate into mature oligodendrocytes with multiple cellular processes which recognize and ensheath neuronal axons. During differentiation, oligodendrocytes undergo dramatic morphological changes requiring cytoskeletal rearrangements which need to be tightly regulated. The non-receptor tyrosine kinase Fyn plays a central role in oligodendrocyte differentiation and myelination. In order to improve our understanding of the role of oligodendroglial Fyn kinase, we have identified Fyn targets in these cells. Purification and mass-spectrometric analysis of tyrosine-phosphorylated proteins in response to overexpressed active Fyn in the oligodendrocyte precursor cell line Oli-neu, yielded the adaptor molecule p130Cas. We analyzed the function of this Fyn target in oligodendroglial cells and observed that reduction of p130Cas levels by siRNA affects process outgrowth, the thickness of cellular processes and migration behavior of Oli-neu cells. Furthermore, long term p130Cas reduction results in decreased cell numbers as a result of increased apoptosis in cultured primary oligodendrocytes. Our data contribute to understanding the molecular events taking place during oligodendrocyte migration and morphological differentiation and have implications for myelin formation.
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Affiliation(s)
- Constantin Gonsior
- Department of Biology, Molecular Cell Biology, Johannes Gutenberg-University of Mainz, Mainz, Germany
| | - Fabien Binamé
- Department of Biology, Molecular Cell Biology, Johannes Gutenberg-University of Mainz, Mainz, Germany
| | - Carsten Frühbeis
- Department of Biology, Molecular Cell Biology, Johannes Gutenberg-University of Mainz, Mainz, Germany
| | - Nina M. Bauer
- Institute of Physiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Peter Hoch-Kraft
- Department of Biology, Molecular Cell Biology, Johannes Gutenberg-University of Mainz, Mainz, Germany
| | - Heiko J. Luhmann
- Institute of Physiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Jacqueline Trotter
- Department of Biology, Molecular Cell Biology, Johannes Gutenberg-University of Mainz, Mainz, Germany
| | - Robin White
- Institute of Physiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
- * E-mail:
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15
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Zhang X, Moore SW, Iskratsch T, Sheetz MP. N-WASP-directed actin polymerization activates Cas phosphorylation and lamellipodium spreading. J Cell Sci 2014; 127:1394-405. [PMID: 24481817 DOI: 10.1242/jcs.134692] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Tyrosine phosphorylation of the substrate domain of Cas (CasSD) correlates with increased cell migration in healthy and diseased cells. Here, we address the mechanism leading to the phosphorylation of CasSD in the context of fibronectin-induced early spreading of fibroblasts. We have previously demonstrated that mechanical stretching of CasSD exposes phosphorylation sites for Src family kinases (SFKs). Surprisingly, phosphorylation of CasSD was independent of myosin contractile activity but dependent on actin polymerization. Furthermore, we found that CasSD phosphorylation in the early stages of cell spreading required: (1) integrin anchorage and integrin-mediated activation of SFKs, (2) association of Cas with focal adhesion kinase (FAK), and (3) N-WASP-driven actin-assembly activity. These findings, and analyses of the interactions of the Cas domains, indicate that the N-terminus of Cas associates with the FAK-N-WASP complex at the protrusive edge of the cell and that the C-terminus of Cas associates with the immobilized integrin-SFK cluster. Thus, extension of the leading edge mediated by actin polymerization could stretch Cas during early cell spreading, priming it for phosphorylation.
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Affiliation(s)
- Xian Zhang
- Department of Biological Sciences, Columbia University, 1212 Amsterdam Avenue, New York, NY 10027, USA
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16
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Goldmann WH. Vinculin-p130Cas interaction is critical for focal adhesion dynamics and mechano-transduction. Cell Biol Int 2013; 38:283-6. [PMID: 24497348 DOI: 10.1002/cbin.10204] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 11/01/2013] [Indexed: 11/09/2022]
Abstract
Adherent cells, when mechanically stressed, show a wide range of responses including large-scale changes in their mechanical behaviour and gene expression pattern. This is in part facilitated by activating the focal adhesion (FA) protein p130Cas through force-induced conformational changes that lead to the phosphorylation by src family kinases. Janostiak et al. [Janostiak et al. Cell Mol Life Sci (2013) DOI 10.1007/s00018-013-1450-x] have reported that the phosphorylation site Y12 on the SH3 domain of p130Cas modulates the binding with vinculin, a prominent mechano-coupling protein in FAs. Tension changes in FAs (due to the anchorage of the SH3 domain and C-terminal) bring about an extension of the substrate domain of p130Cas by unmasking the phosphorylation sites. These observations demonstrate that vinculin is an important modulator of the p130Cas-mediated mechano-transduction pathway in cells. The central aim should be now to test that vinculin is critical for p130Cas incorporation into the focal adhesion complex and for transmitting forces to the p130Cas molecule.
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Affiliation(s)
- Wolfgang H Goldmann
- Center for Medical Physics and Technology, Biophysics Group, Friedrich-Alexander-University of Erlangen-Nuremberg, Henkestrasse 91, 91052, Erlangen, Germany
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17
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Reynolds AB, Kanner SB, Bouton AH, Schaller MD, Weed SA, Flynn DC, Parsons JT. SRChing for the substrates of Src. Oncogene 2013; 33:4537-47. [PMID: 24121272 DOI: 10.1038/onc.2013.416] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Revised: 08/16/2013] [Accepted: 08/17/2013] [Indexed: 12/12/2022]
Abstract
By the mid 1980's, it was clear that the transforming activity of oncogenic Src was linked to the activity of its tyrosine kinase domain and attention turned to identifying substrates, the putative next level of control in the pathway to transformation. Among the first to recognize the potential of phosphotyrosine-specific antibodies, Parsons and colleagues launched a risky shotgun-based approach that led ultimately to the cDNA cloning and functional characterization of many of today's best-known Src substrates (for example, p85-Cortactin, p110-AFAP1, p130Cas, p125FAK and p120-catenin). Two decades and over 6000 citations later, the original goals of the project may be seen as secondary to the enormous impact of these protein substrates in many areas of biology. At the request of the editors, this review is not restricted to the current status of the substrates, but reflects also on the anatomy of the project itself and some of the challenges and decisions encountered along the way.
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Affiliation(s)
- A B Reynolds
- Department of Cancer Biology, Vanderbilt University, Nashville, TN, USA
| | - S B Kanner
- Arrowhead Research Corporation, Madison, WI, USA
| | - A H Bouton
- Departments of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - M D Schaller
- Department of Biochemistry, 3124 HSN, Robert C. Byrd Health Sciences Center, West Virginia University School of Medicine, Morgantown, WV, USA
| | - S A Weed
- Department of Neurobiology and Anatomy, 1833 Mary Babb Randolph Cancer Center, Robert C. Byrd Health Sciences Center, West Virginia University School of Medicine, Morgantown, WV, USA
| | - D C Flynn
- Department of Medical Lab Sciences, College of Health Sciences, University of Delaware, Newark, DE, USA
| | - J T Parsons
- Departments of Microbiology, Immunology and Cancer Biology, University of Virginia Cancer Center, Charlottesville, VA, USA
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18
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CAS directly interacts with vinculin to control mechanosensing and focal adhesion dynamics. Cell Mol Life Sci 2013; 71:727-44. [PMID: 23974298 PMCID: PMC3901934 DOI: 10.1007/s00018-013-1450-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 07/19/2013] [Accepted: 08/05/2013] [Indexed: 12/31/2022]
Abstract
Focal adhesions are cellular structures through which both mechanical forces and regulatory signals are transmitted. Two focal adhesion-associated proteins, Crk-associated substrate (CAS) and vinculin, were both independently shown to be crucial for the ability of cells to transmit mechanical forces and to regulate cytoskeletal tension. Here, we identify a novel, direct binding interaction between CAS and vinculin. This interaction is mediated by the CAS SRC homology 3 domain and a proline-rich sequence in the hinge region of vinculin. We show that CAS localization in focal adhesions is partially dependent on vinculin, and that CAS–vinculin coupling is required for stretch-induced activation of CAS at the Y410 phosphorylation site. Moreover, CAS–vinculin binding significantly affects the dynamics of CAS and vinculin within focal adhesions as well as the size of focal adhesions. Finally, disruption of CAS binding to vinculin reduces cell stiffness and traction force generation. Taken together, these findings strongly implicate a crucial role of CAS–vinculin interaction in mechanosensing and focal adhesion dynamics.
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19
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Macrophage fusion is controlled by the cytoplasmic protein tyrosine phosphatase PTP-PEST/PTPN12. Mol Cell Biol 2013; 33:2458-69. [PMID: 23589331 DOI: 10.1128/mcb.00197-13] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Macrophages can undergo cell-cell fusion, leading to the formation of multinucleated giant cells and osteoclasts. This process is believed to promote the proteolytic activity of macrophages toward pathogens, foreign bodies, and extracellular matrices. Here, we examined the role of PTP-PEST (PTPN12), a cytoplasmic protein tyrosine phosphatase, in macrophage fusion. Using a macrophage-targeted PTP-PEST-deficient mouse, we determined that PTP-PEST was not needed for macrophage differentiation or cytokine production. However, it was necessary for interleukin-4-induced macrophage fusion into multinucleated giant cells in vitro. It was also needed for macrophage fusion following implantation of a foreign body in vivo. Moreover, in the RAW264.7 macrophage cell line, PTP-PEST was required for receptor activator of nuclear factor kappa-B ligand (RANKL)-triggered macrophage fusion into osteoclasts. PTP-PEST had no impact on expression of fusion mediators such as β-integrins, E-cadherin, and CD47, which enable macrophages to become fusion competent. However, it was needed for polarization of macrophages, migration induced by the chemokine CC chemokine ligand 2 (CCL2), and integrin-induced spreading, three key events in the fusion process. PTP-PEST deficiency resulted in specific hyperphosphorylation of the protein tyrosine kinase Pyk2 and the adaptor paxillin. Moreover, a fusion defect was induced upon treatment of normal macrophages with a Pyk2 inhibitor. Together, these data argue that macrophage fusion is critically dependent on PTP-PEST. This function is seemingly due to the ability of PTP-PEST to control phosphorylation of Pyk2 and paxillin, thereby regulating cell polarization, migration, and spreading.
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20
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Krishnan H, Miller WT, Goldberg GS. SRC points the way to biomarkers and chemotherapeutic targets. Genes Cancer 2012; 3:426-35. [PMID: 23226580 DOI: 10.1177/1947601912458583] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The role of Src in tumorigenesis has been extensively studied since the work of Peyton Rous over a hundred years ago. Src is a non-receptor tyrosine kinase that plays key roles in signaling pathways controlling tumor cell growth and migration. Src regulates the activities of numerous molecules to induce cell transformation. However, transformed cells do not always migrate and realize their tumorigenic potential. They can be normalized by surrounding nontransformed cells by a process called contact normalization. Tumor cells need to override contact normalization to become malignant or metastatic. In this review, we discuss the role of Src in cell migration and contact normalization, with emphasis on Cas and Abl pathways. This paradigm illuminates several chemotherapeutic targets and may lead to the identification of new biomarkers and the development of effective anticancer treatments.
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Affiliation(s)
- Harini Krishnan
- University of Medicine and Dentistry of New Jersey, Graduate School of Biomedical Sciences, School of Osteopathic Medicine, Stratford, NJ, USA
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21
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Moore SW, Zhang X, Lynch CD, Sheetz MP. Netrin-1 attracts axons through FAK-dependent mechanotransduction. J Neurosci 2012; 32:11574-85. [PMID: 22915102 PMCID: PMC3461192 DOI: 10.1523/jneurosci.0999-12.2012] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 06/01/2012] [Accepted: 06/29/2012] [Indexed: 11/21/2022] Open
Abstract
The mechanism by which extracellular cues influence intracellular biochemical cascades that guide axons is important, yet poorly understood. Because of the mechanical nature of axon extension, we explored whether the physical interactions of growth cones with their guidance cues might be involved. In the context of mouse spinal commissural neuron axon attraction to netrin-1, we found that mechanical attachment of netrin-1 to the substrate was required for axon outgrowth, growth cone expansion, axon attraction and phosphorylation of focal adhesion kinase (FAK) and Crk-associated substrate (CAS). Myosin II activity was necessary for traction forces >30 pN on netrin-1. Interestingly, while these myosin II-dependent forces on netrin-1 substrates or beads were needed to increase the kinase activity and phosphorylation of FAK, they were not necessary for netrin-1 to increase CAS phosphorylation. When FAK kinase activity was inhibited, the growth cone's ability to recruit additional adhesions and to generate forces >60 pN on netrin-1 was disrupted. Together, these findings demonstrate an important role for mechanotransduction during chemoattraction to netrin-1 and that mechanical activation of FAK reinforces interactions with netrin-1 allowing greater forces to be exerted.
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Affiliation(s)
- Simon W Moore
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA.
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22
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23
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Abstract
Anchorage-independent growth is the most significant hallmark of cell transformation, which has an intimate relevance to cancer. Anchorage or adhesion physically links cells to the extracellular matrix and allows the transmission of external mechanical cues to intracellular signaling machineries. Transformation involves acquiring the ability to proliferate without requiring mechanically initiated signal transduction, known as mechanotransduction. A number of signaling and cytoskeletal molecules are located at focal adhesions. Src and its related proteins, including p130Cas, localize to adhesion sites, where their functions can be mechanically regulated. In addition, the aberrant activation and expression of Src and p130Cas are linked to transformation and malignancy both in vitro and in vivo. These findings shed light on the importance of mechanotransduction in tumorigenesis and the regulation of cancer progression and also provide insights into the mechanical aspects of cancer signaling.
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Affiliation(s)
- Hiroyuki Matsui
- Laboratory for Mechanical Medicine, Locomotive Syndrome Research Institute, Nadogaya Hospital, Kashiwa, Japan
| | - Ichiro Harada
- Laboratory for Mechanical Medicine, Locomotive Syndrome Research Institute, Nadogaya Hospital, Kashiwa, Japan
| | - Yasuhiro Sawada
- Laboratory for Mechanical Medicine, Locomotive Syndrome Research Institute, Nadogaya Hospital, Kashiwa, Japan
- Mechanobiology Institute of Singapore, National University of Singapore, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore
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24
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Zhong J, Baquiran JB, Bonakdar N, Lees J, Ching YW, Pugacheva E, Fabry B, O'Neill GM. NEDD9 stabilizes focal adhesions, increases binding to the extra-cellular matrix and differentially effects 2D versus 3D cell migration. PLoS One 2012; 7:e35058. [PMID: 22509381 PMCID: PMC3324407 DOI: 10.1371/journal.pone.0035058] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Accepted: 03/08/2012] [Indexed: 12/30/2022] Open
Abstract
The speed of cell migration on 2-dimensional (2D) surfaces is determined by the rate of assembly and disassembly of clustered integrin receptors known as focal adhesions. Different modes of cell migration that have been described in 3D environments are distinguished by their dependence on integrin-mediated interactions with the extra-cellular matrix. In particular, the mesenchymal invasion mode is the most dependent on focal adhesion dynamics. The focal adhesion protein NEDD9 is a key signalling intermediary in mesenchymal cell migration, however whether NEDD9 plays a role in regulating focal adhesion dynamics has not previously been reported. As NEDD9 effects on 2D migration speed appear to depend on the cell type examined, in the present study we have used mouse embryo fibroblasts (MEFs) from mice in which the NEDD9 gene has been depleted (NEDD9 -/- MEFs). This allows comparison with effects of other focal adhesion proteins that have previously been demonstrated using MEFs. We show that focal adhesion disassembly rates are increased in the absence of NEDD9 expression and this is correlated with increased paxillin phosphorylation at focal adhesions. NEDD9-/- MEFs have increased rates of migration on 2D surfaces, but conversely, migration of these cells is significantly reduced in 3D collagen gels. Importantly we show that myosin light chain kinase is activated in 3D in the absence of NEDD9 and is conversely inhibited in 2D cultures. Measurement of adhesion strength reveals that NEDD9-/- MEFs have decreased adhesion to fibronectin, despite upregulated α5β1 fibronectin receptor expression. We find that β1 integrin activation is significantly suppressed in the NEDD9-/-, suggesting that in the absence of NEDD9 there is decreased integrin receptor activation. Collectively our data suggest that NEDD9 may promote 3D cell migration by slowing focal adhesion disassembly, promoting integrin receptor activation and increasing adhesion force to the ECM.
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Affiliation(s)
- Jessie Zhong
- Children's Cancer Research Unit, Kids Research Institute, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
- Discipline of Paediatrics and Child Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Jaime B. Baquiran
- Children's Cancer Research Unit, Kids Research Institute, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | - Navid Bonakdar
- Department of Physics, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Justin Lees
- Children's Cancer Research Unit, Kids Research Institute, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | - Yu Wooi Ching
- Children's Cancer Research Unit, Kids Research Institute, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | - Elena Pugacheva
- Mary Babb Randolph Cancer Center (MBRCC), West Virginia University, Morgantown, West Virginia, United States of America
| | - Ben Fabry
- Department of Physics, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Geraldine M. O'Neill
- Children's Cancer Research Unit, Kids Research Institute, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
- Discipline of Paediatrics and Child Health, The University of Sydney, Sydney, New South Wales, Australia
- * E-mail:
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25
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Janoštiak R, Tolde O, Brůhová Z, Novotný M, Hanks SK, Rösel D, Brábek J. Tyrosine phosphorylation within the SH3 domain regulates CAS subcellular localization, cell migration, and invasiveness. Mol Biol Cell 2011; 22:4256-67. [PMID: 21937722 PMCID: PMC3216652 DOI: 10.1091/mbc.e11-03-0207] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Crk-associated substrate (CAS) Tyr-12 phosphorylation has an important role in ligand binding, CAS localization, turnover of adhesion structures, migration, and invasiveness. CAS Tyr-12 phosphorylation thus possibly represents a novel regulatory mechanism by which CAS-mediated signaling could trigger different cellular responses. Crk-associated substrate (CAS) is a major tyrosine-phosphorylated protein in cells transformed by v-crk and v-src oncogenes and plays an important role in invasiveness of Src-transformed cells. A novel phosphorylation site on CAS, Tyr-12 (Y12) within the ligand-binding hydrophobic pocket of the CAS SH3 domain, was identified and found to be enriched in Src-transformed cells and invasive human carcinoma cells. To study the biological significance of CAS Y12 phosphorylation, phosphomimicking Y12E and nonphosphorylatable Y12F mutants of CAS were studied. The phosphomimicking mutation decreased interaction of the CAS SH3 domain with focal adhesion kinase (FAK) and PTP-PEST and reduced tyrosine phosphorylation of FAK. Live-cell imaging showed that green fluorescent protein–tagged CAS Y12E mutant is, in contrast to wild-type or Y12F CAS, excluded from focal adhesions but retains its localization to podosome-type adhesions. Expression of CAS-Y12F in cas–/– mouse embryonic fibroblasts resulted in hyperphosphorylation of the CAS substrate domain, and this was associated with slower turnover of focal adhesions and decreased cell migration. Moreover, expression of CAS Y12F in Src-transformed cells greatly decreased invasiveness when compared to wild-type CAS expression. These findings reveal an important role of CAS Y12 phosphorylation in the regulation of focal adhesion assembly, cell migration, and invasiveness of Src-transformed cells.
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Affiliation(s)
- Radoslav Janoštiak
- Department of Cell Biology, Charles University, 12843 Prague, Czech Republic
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26
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Schedin P, Keely PJ. Mammary gland ECM remodeling, stiffness, and mechanosignaling in normal development and tumor progression. Cold Spring Harb Perspect Biol 2011; 3:a003228. [PMID: 20980442 DOI: 10.1101/cshperspect.a003228] [Citation(s) in RCA: 321] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Cells of the mammary gland are in intimate contact with other cells and with the extracellular matrix (ECM), both of which provide not only a biochemical context, but a mechanical context as well. Cell-mediated contraction allows cells to sense the stiffness of their microenvironment, and respond with appropriate mechanosignaling events that regulate gene expression and differentiation. ECM composition and organization are tightly regulated throughout development of the mammary gland, resulting in corresponding regulation of the mechanical environment and proper tissue architecture. Mechanical regulation is also at play during breast carcinoma progression, as changes in ECM deposition, composition, and organization accompany breast carcinoma. These changes result in stiffer matrices that activate mechanosignaling pathways and thereby induce cell proliferation, facilitate local tumor cell invasion, and promote progression. Thus, understanding the role of forces in the mammary gland is crucial to understanding both normal developmental and pathological processes.
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Affiliation(s)
- Pepper Schedin
- Department of Medicine, Division of Medical Oncology, University of Colorado, Denver, Colorado 80045, USA
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27
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Sarfstein R, Bruchim I, Fishman A, Werner H. The mechanism of action of the histone deacetylase inhibitor vorinostat involves interaction with the insulin-like growth factor signaling pathway. PLoS One 2011; 6:e24468. [PMID: 21931726 PMCID: PMC3169604 DOI: 10.1371/journal.pone.0024468] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Accepted: 08/10/2011] [Indexed: 12/17/2022] Open
Abstract
A correlation between components of the insulin-like growth factor (IGF) system and endometrial cancer risk has been shown in recent studies. The antitumor action of vorinostat, a histone deacetylase inhibitor, involves changes in the expression of specific genes via acetylation of histones and transcription factors. The aim of this study was to establish whether vorinostat can modify the expression of specific genes related to the IGF-I receptor (IGF-IR) signaling pathway and revert the transformed phenotype. Human endometrioid (Type I, Ishikawa) and uterine serous papillary (Type II, USPC-2) endometrial cancer cell lines were treated with vorinostat in the presence or absence of IGF-I. Vorinostat increased IGF-IR phosphorylation, produced acetylation of histone H3, up-regulated pTEN and p21 expression, and reduced p53 and cyclin D1 levels in Ishikawa cells. Vorinostat up-regulated IGF-IR and p21 expression, produced acetylation of histone H3, and down-regulated the expression of total AKT, pTEN and cyclin D1 in USPC-2 cells. Of interest, IGF-IR activation was associated with a major elevation in IGF-IR promoter activity. In addition, vorinostat treatment induced apoptosis in both cell lines and abolished the anti-apoptotic activity of IGF-I both in the absence or presence of a humanized monoclonal IGF-IR antibody, MK-0646. Finally, vorinostat treatment led to a significant decrease in proliferation and colony forming capability in both cell lines. In summary, our studies demonstrate that vorinostat exhibits a potent apoptotic and anti-proliferative effect in both Type I and II endometrial cancer cells, thus suggesting that endometrial cancer may be therapeutically targeted by vorinostat.
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Affiliation(s)
- Rive Sarfstein
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ilan Bruchim
- Gynecologic Oncology Unit, Department of Obstetrics and Gynecology, Meir Medical Center, Kfar Sava, Israel
| | - Ami Fishman
- Gynecologic Oncology Unit, Department of Obstetrics and Gynecology, Meir Medical Center, Kfar Sava, Israel
| | - Haim Werner
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
- * E-mail:
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28
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Tazaki T, Sasaki T, Uto K, Yamasaki N, Tashiro S, Sakai R, Tanaka M, Oda H, Honda ZI, Honda H. p130Cas, Crk-associated substrate plays essential roles in liver development by regulating sinusoidal endothelial cell fenestration. Hepatology 2010; 52:1089-99. [PMID: 20623582 DOI: 10.1002/hep.23767] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
UNLABELLED p130Cas, Crk-associated substrate (Cas), is an adaptor/scaffold protein that plays a central role in actin cytoskeletal reorganization. We previously showed that mice in which Cas was deleted (Cas(-/-)) died in utero because of early cardiovascular maldevelopment. To further investigate the in vivo roles of Cas, we generated mice with a hypomorphic Cas allele lacking the exon 2-derived region (Cas(Deltaex2/Deltaex2)), which encodes Src homology domain 3 (SH3) of Cas. Cas(Deltaex2/Deltaex2) mice again died as embryos, but they particularly showed progressive liver degeneration with hepatocyte apoptosis. Because Cas expression in the liver is preferentially detected in sinusoidal endothelial cells (SECs), the observed hepatocyte apoptosis was most likely ascribable to impaired function of SECs. To address this possibility, we stably introduced a Cas mutant lacking the SH3 domain (Cas DeltaSH3) into an SEC line (NP31). Intriguingly, the introduction of Cas DeltaSH3 induced a loss of fenestrae, the characteristic cell-penetrating pores in SECs that serve as a critical route for supplying oxygen and nutrients to hepatocytes. The disappearance of fenestrae in Cas DeltaSH3-expressing cells was associated with an attenuation of actin stress fiber formation, a marked reduction in tyrosine phosphorylation of Cas, and defective binding of Cas to CrkII. CONCLUSION Cas plays pivotal roles in liver development through the reorganization of the actin cytoskeleton and formation of fenestrae in SECs.
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Affiliation(s)
- Tatsuya Tazaki
- Department of Disease Model, Hiroshima University, Hiroshima, Japan
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29
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Tikhmyanova N, Tulin AV, Roegiers F, Golemis EA. Dcas supports cell polarization and cell-cell adhesion complexes in development. PLoS One 2010; 5:e12369. [PMID: 20808771 PMCID: PMC2927436 DOI: 10.1371/journal.pone.0012369] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Accepted: 07/29/2010] [Indexed: 01/17/2023] Open
Abstract
Mammalian Cas proteins regulate cell migration, division and survival, and are often deregulated in cancer. However, the presence of four paralogous Cas family members in mammals (BCAR1/p130Cas, EFS/Sin1, NEDD9/HEF1/Cas-L, and CASS4/HEPL) has limited their analysis in development. We deleted the single Drosophila Cas gene, Dcas, to probe the developmental function of Dcas. Loss of Dcas had limited effect on embryonal development. However, we found that Dcas is an important modulator of the severity of the developmental phenotypes of mutations affecting integrins (If and mew) and their downstream effectors Fak56D or Src42A. Strikingly, embryonic lethal Fak56D-Dcas double mutant embryos had extensive cell polarity defects, including mislocalization and reduced expression of E-cadherin. Further genetic analysis established that loss of Dcas modified the embryonal lethal phenotypes of embryos with mutations in E-cadherin (Shg) or its signaling partners p120- and beta-catenin (Arm). These results support an important role for Cas proteins in cell-cell adhesion signaling in development.
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Affiliation(s)
- Nadezhda Tikhmyanova
- Fox Chase Cancer Center, Philadelphia, Pennsylvania, United States of America
- Department of Biochemistry, Drexel University Medical School, Philadelphia, Pennsylvania, United States of America
| | - Alexei V. Tulin
- Fox Chase Cancer Center, Philadelphia, Pennsylvania, United States of America
| | - Fabrice Roegiers
- Fox Chase Cancer Center, Philadelphia, Pennsylvania, United States of America
| | - Erica A. Golemis
- Fox Chase Cancer Center, Philadelphia, Pennsylvania, United States of America
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30
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Funasaka K, Ito S, Hasegawa H, Goldberg GS, Hirooka Y, Goto H, Hamaguchi M, Senga T. Cas utilizes Nck2 to activate Cdc42 and regulate cell polarization during cell migration in response to wound healing. FEBS J 2010; 277:3502-13. [PMID: 20637038 DOI: 10.1111/j.1742-4658.2010.07752.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Integrin-mediated activation of Cdc42 is essential for cell polarization, whereas the integrin adaptor protein Cas is required for cell migration during wound healing. After phosphorylation on tyrosine residues, Cas recruits the adaptor proteins Crk and Nck to execute integrin-mediated signals. However, the mechanisms leading to Cdc42 activation and its relationship with Cas, Crk and Nck have not been elucidated clearly. In the present study, we demonstrate that Cas utilizes Nck2 to activate Cdc42 and induce cell polarization in response to wounding. By contrast, Cas recruits CrkII to activate Rac1 and promote the extension of cell protrusions needed for cell motility. These results indicate that Cas utilizes Nck2 and CrkII in a coordinated set of distinct pathways leading to cell migration.
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Affiliation(s)
- Kohei Funasaka
- Department of Gastroenterology, Nagoya University Graduate School of Medicine, Japan
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Cunningham-Edmondson AC, Hanks SK. p130Cas substrate domain signaling promotes migration, invasion, and survival of estrogen receptor-negative breast cancer cells. BREAST CANCER-TARGETS AND THERAPY 2009; 1:39-52. [PMID: 24367162 DOI: 10.2147/bctt.s6255] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Elevated Src tyrosine kinase activity is commonly observed in breast cancer and likely contributes to neoplasia and malignancy. p130Cas ("Crk-associated substrate") is a major Src substrate found at the sites where integrins mediate cell adhesion to the extracellular matrix. Src phosphorylates multiple tyrosines in the p130Cas "substrate domain" (SD) and this signaling event has been implicated in the promotion of cell motility, primarily from studies on fibroblasts. In breast cancer, studies on p130Cas have focused on its role in conferring antiestrogen resistance to cells that express the estrogen receptor (ER+). However, little is known regarding the role of p130Cas in the more aggressive estrogen receptor negative (ER-) breast cancers for which there is a need for development of effective targeted therapies. We found high levels of p130Cas SD tyrosine phosphorylation to be a common characteristic of ER- breast cancer cell lines, with particularly high levels observed for the BT-549 cell line. Using RNA interference to knock down p130Cas expression in BT-549 cells, combined with rescue by WT p130Cas versus a signaling-deficient control, we provide evidence that p130Cas SD tyrosine phosphorylation is an important signaling event in the migration, invasion, proliferation, and survival of this ER-breast cancer cell line.
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Affiliation(s)
- Anna C Cunningham-Edmondson
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA ; Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, GA, USA
| | - Steven K Hanks
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
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Schuh NR, Guerrero MS, Schrecengost RS, Bouton AH. BCAR3 regulates Src/p130 Cas association, Src kinase activity, and breast cancer adhesion signaling. J Biol Chem 2009; 285:2309-17. [PMID: 19940159 DOI: 10.1074/jbc.m109.046631] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The nonreceptor protein-tyrosine kinase c-Src is frequently overexpressed and/or activated in a variety of cancers, including those of the breast. Several heterologous binding partners of c-Src have been shown to regulate its catalytic activity by relieving intramolecular autoinhibitory interactions. One such protein, p130(Cas) (Cas), is expressed at high levels in both breast cancer cell lines and breast tumors, providing a potential mechanism for c-Src activation in breast cancers. The Cas-binding protein BCAR3 (breast cancer antiestrogen resistance-3) is expressed at high levels in invasive breast cancer cell lines, and this molecule has previously been shown to coordinate with Cas to increase c-Src activity in COS-1 cells. In this study, we show for the first time using gain- and loss-of-function approaches that BCAR3 regulates c-Src activity in the endogenous setting of breast cancer cells. We further show that BCAR3 regulates the interaction between Cas and c-Src, both qualitatively as well as quantitatively. Finally, we present evidence that the coordinated activity of these proteins contributes to breast cancer cell adhesion signaling and spreading. Based on these data, we propose that the c-Src/Cas/BCAR3 signaling axis is a prominent regulator of c-Src activity, which in turn controls cell behaviors that lead to aggressive and invasive breast tumor phenotypes.
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Affiliation(s)
- Natasha R Schuh
- Department of Microbiology, University of Virginia Health System, Charlottesville, Virginia 22908, USA
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Patwardhan P, Shiba K, Gordon C, Craddock BP, Tamiko M, Miller WT. Synthesis of functional signaling domains by combinatorial polymerization of phosphorylation motifs. ACS Chem Biol 2009; 4:751-8. [PMID: 19627099 DOI: 10.1021/cb900059f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The adaptor protein Cas contains a core substrate domain with multiple YXXP motifs that are phosphorylated by Src and other tyrosine kinases. Here, we used a synthetic strategy to determine the importance of the arrangement, spacing, and identity of the YXXP motifs. By polymerizing short DNA sequences encoding two phosphorylation motifs, we created a panel of Cas mutants in which the entire substrate domain was replaced by synthetic domains containing random numbers and arrangements of the motifs. Most of these synthetic Cas variants were recognized and phosphorylated by Src in vitro and in intact mammalian cells. The random polymer mutants also restored migration activity to Cas knockout cells; even artificial proteins containing a single motif retained some biological function. Our results suggest that the arrangement of Cas motifs is not critical for signaling. This method could be used to identify the minimal functional units in other signaling proteins.
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Affiliation(s)
- Parag Patwardhan
- Department of Physiology and Biophysics, School of Medicine, State University of New York at Stony Brook, Stony Brook, New York 11794
| | - Kiyotaka Shiba
- Department of Protein Engineering, Cancer Institute, Japanese Foundation for Cancer Research, Tokyo 135-8550, Japan
| | - Chris Gordon
- Department of Physiology and Biophysics, School of Medicine, State University of New York at Stony Brook, Stony Brook, New York 11794
| | - Barbara P. Craddock
- Department of Physiology and Biophysics, School of Medicine, State University of New York at Stony Brook, Stony Brook, New York 11794
| | - Minamisawa Tamiko
- Department of Protein Engineering, Cancer Institute, Japanese Foundation for Cancer Research, Tokyo 135-8550, Japan
| | - W. Todd Miller
- Department of Physiology and Biophysics, School of Medicine, State University of New York at Stony Brook, Stony Brook, New York 11794
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Huveneers S, Danen EHJ. Adhesion signaling - crosstalk between integrins, Src and Rho. J Cell Sci 2009; 122:1059-69. [PMID: 19339545 DOI: 10.1242/jcs.039446] [Citation(s) in RCA: 640] [Impact Index Per Article: 42.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Interactions between cells and the extracellular matrix coordinate signaling pathways that control various aspects of cellular behavior. Integrins sense the physical properties of the extracellular matrix and organize the cytoskeleton accordingly. In turn, this modulates signaling pathways that are triggered by various other transmembrane receptors and augments the cellular response to growth factors. Over the past years, it has become clear that there is extensive crosstalk between integrins, Src-family kinases and Rho-family GTPases at the heart of such adhesion signaling. In this Commentary, we discuss recent advances in our understanding of the dynamic regulation of the molecular connections between these three protein families. We also discuss how this signaling network can regulate a range of cellular processes that are important for normal tissue function and disease, including cell adhesion, spreading, migration and mechanotransduction.
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Affiliation(s)
- Stephan Huveneers
- Division of Toxicology, Leiden Amsterdam Center for Drug Research, Leiden University, 2300 RA Leiden, The Netherlands.
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Abstract
Vascular smooth muscle is a key effector in the wall of blood vessels during the pathogenesis of hypertension. Various factors directly elicit smooth muscle cell contraction, migration, growth, and hypertrophy, which lead to the progression of hypertension. Crk-associated substrate (CAS), the first discovered member of the adapter protein CAS family, has recently emerged as a critical cellular component that regulates smooth muscle functions. In this review, the molecular structure and protein interactions of the CAS family members are summarized. Evidence for the role of CAS in the regulation of vascular smooth muscle contractility, cell migration, hypertrophy, and growth is presented. Regulation of CAS by novel tyrosine kinases/phosphatases and unique downstream signaling partners of CAS are also discussed. These new findings establish the important role for CAS in regulating vascular smooth muscle functions. The CAS-associated processes may be new biological targets for the development of new treatment of cardiovascular diseases such as hypertension.
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Affiliation(s)
- Dale D Tang
- Center for Cardiovascular Sciences, Albany Medical College, Albany, New York 12208, USA.
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Provenzano PP, Inman DR, Eliceiri KW, Beggs HE, Keely PJ. Mammary epithelial-specific disruption of focal adhesion kinase retards tumor formation and metastasis in a transgenic mouse model of human breast cancer. THE AMERICAN JOURNAL OF PATHOLOGY 2008; 173:1551-65. [PMID: 18845837 DOI: 10.2353/ajpath.2008.080308] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Focal adhesion kinase (FAK) is a central regulator of the focal adhesion, influencing cell proliferation, survival, and migration. Despite evidence demonstrating FAK overexpression in human cancer, its role in tumor initiation and progression is not well understood. Using Cre/LoxP technology to specifically knockout FAK in the mammary epithelium, we showed that FAK is not required for tumor initiation but is required for tumor progression. The mechanistic underpinnings of these results suggested that FAK regulates clinically relevant gene signatures and multiple signaling complexes associated with tumor progression and metastasis, such as Src, ERK, and p130Cas. Furthermore, a systems-level analysis identified FAK as a major regulator of the tumor transcriptome, influencing genes associated with adhesion and growth factor signaling pathways, and their cross talk. Additionally, FAK was shown to down-regulate the expression of clinically relevant proliferation- and metastasis-associated gene signatures, as well as an enriched group of genes associated with the G(2) and G(2)/M phases of the cell cycle. Computational analysis of transcription factor-binding sites within ontology-enriched or clustered gene sets suggested that the differentially expressed proliferation- and metastasis-associated genes in FAK-null cells were regulated through a common set of transcription factors, including p53. Therefore, FAK acts as a primary node in the activated signaling network in transformed motile cells and is a prime candidate for novel therapeutic interventions to treat aggressive human breast cancers.
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Affiliation(s)
- Paolo P Provenzano
- Department of Pharmacology, Laboratory of Molecular Biology, Madison, WI 53706, USA. ppproven@ wisc.edu
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Sharma A, Mayer BJ. Phosphorylation of p130Cas initiates Rac activation and membrane ruffling. BMC Cell Biol 2008; 9:50. [PMID: 18793427 PMCID: PMC2553404 DOI: 10.1186/1471-2121-9-50] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Accepted: 09/15/2008] [Indexed: 12/27/2022] Open
Abstract
Background Non-receptor tyrosine kinases (NTKs) regulate physiological processes such as cell migration, differentiation, proliferation, and survival by interacting with and phosphorylating a large number of substrates simultaneously. This makes it difficult to attribute a particular biological effect to the phosphorylation of a particular substrate. We developed the Functional Interaction Trap (FIT) method to phosphorylate specifically a single substrate of choice in living cells, thereby allowing the biological effect(s) of that phosphorylation to be assessed. In this study we have used FIT to investigate the effects of specific phosphorylation of p130Cas, a protein implicated in cell migration. We have also used this approach to address a controversy regarding whether it is Src family kinases or focal adhesion kinase (FAK) that phosphorylates p130Cas in the trimolecular Src-FAK-p130Cas complex. Results We show here that SYF cells (mouse fibroblasts lacking the NTKs Src, Yes and Fyn) exhibit a low level of basal tyrosine phosphorylation at focal adhesions. FIT-mediated tyrosine phosphorylation of NTK substrates p130Cas, paxillin and FAK and cortactin was observed at focal adhesions, while FIT-mediated phosphorylation of cortactin was also seen at the cell periphery. Phosphorylation of p130Cas in SYF cells led to activation of Rac1 and increased membrane ruffling and lamellipodium formation, events associated with cell migration. We also found that the kinase activity of Src and not FAK is essential for phosphorylation of p130Cas when the three proteins exist as a complex in focal adhesions. Conclusion These results demonstrate that tyrosine phosphorylation of p130Cas is sufficient for its localization to focal adhesions and for activation of downstream signaling events associated with cell migration. FIT provides a valuable tool to evaluate the contribution of individual components of the response to signals with multiple outputs, such as activation of NTKs.
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Affiliation(s)
- Alok Sharma
- Department of Pharmaceutical Sciences, Massachusetts College of Pharmacy and Health Sciences, 1260 Elm Street, Manchester, NH 03101, USA.
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Tazaki T, Miyazaki K, Hiyama E, Nakamoto T, Sakai R, Yamasaki N, Honda ZI, Noda M, Miyasaka N, Sueda T, Honda H. Functional analysis of Src homology 3-encoding exon (exon 2) of p130Cas in primary fibroblasts derived from exon 2-specific knockout mice. Genes Cells 2008; 13:145-57. [PMID: 18233957 DOI: 10.1111/j.1365-2443.2007.01156.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
p130Cas (Cas, Crk-associated substrate) is an adaptor molecule composed of a Src homology 3 (SH3) domain, a substrate domain (SD) and a Src binding domain (SBD). The SH3 domain of Cas associates with focal adhesion kinase (FAK), but its role in cellular function has not fully been understood. To address this issue, we established and analyzed primary fibroblasts derived from mice expressing a truncated Cas lacking exon 2, which encodes the SH3 domain (Cas Deltaexon 2). In comparison to wild-type cells, Cas exon 2(Delta/Delta) cells showed reduced motility, which could be due to impaired tyrosine-phosphorylation of FAK and Cas, reduced FAK/Cas/Src/CrkII binding, and also impaired localization of Cas Deltaexon 2 to focal adhesions on fibronectin. In addition, to analyze downstream signaling pathways regulated by Cas exon 2, we performed microarray analyses. Interestingly, we found that a deficiency of Cas exon 2 up-regulated expression of CXC Chemokine Receptor-4 and CC Chemokine Receptor-5, which may be regulated by IkappaBalpha phosphorylation. These results indicate that the SH3-encoding exon of Cas participates in cell motility, tyrosine-phosphorylation of FAK and Cas, FAK/Cas/Src/CrkII complex formation, recruitment of Cas to focal adhesions and regulation of cell motility-associated gene expression in primary fibroblasts.
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Affiliation(s)
- Tatsuya Tazaki
- Department of Developmental Biology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima 734-8553, Japan
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Takatsuka A, Yagi R, Koike M, Oneyama C, Nada S, Schmedt C, Uchiyama Y, Okada M. Ablation of Csk in neural crest lineages causes corneal anomaly by deregulating collagen fibril organization and cell motility. Dev Biol 2008; 315:474-88. [PMID: 18262517 DOI: 10.1016/j.ydbio.2008.01.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2007] [Revised: 12/29/2007] [Accepted: 01/04/2008] [Indexed: 12/25/2022]
Abstract
Src family kinases (SFKs) have been implicated in the regulation of cell motility. To verify their in vivo roles during development, we generated mutant mice in which Csk, a negative regulator of SFKs, was inactivated in neural crest lineages using the Protein zero promoter in a Cre-loxP system. Inactivation of Csk caused deformities in various tissues of neural crest origins, including facial dysplasia and corneal opacity. In the cornea, the stromal collagen fibril was disorganized and there was an overproduction of collagen 1a1 and several metalloproteases. The corneal endothelium failed to overlie the central region of the eye and the peripheral endothelium displayed a disorganized cytoskeleton. Corneal mesenchymal cells cultured from mutant mice showed attenuated cell motility. In these cells, p130 Crk-associated substrate (Cas) was hyperphosphorylated and markedly downregulated. The expression of a dominant negative Cas (Cas Delta SD) could suppress the cell motility defects. Fluorescence resonance energy transfer analysis revealed that activation of Rac1 and Cdc42 was depolarized in Csk-inactivated cells, which was restored by the expression of either Csk or Cas Delta SD. These results demonstrate that the SFKs/Csk circuit plays crucial roles in corneal development by controlling stromal organization and by ensuring cell motility via the Cas-Rac/Cdc42 pathways.
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Affiliation(s)
- Atsuko Takatsuka
- Department of Oncogene Research, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan
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Estornes Y, Gay F, Gevrey JC, Navoizat S, Nejjari M, Scoazec JY, Chayvialle JA, Saurin JC, Abello J. Differential involvement of destrin and cofilin-1 in the control of invasive properties of Isreco1 human colon cancer cells. Int J Cancer 2007; 121:2162-71. [PMID: 17583572 DOI: 10.1002/ijc.22911] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Actin depolymerizing factor (ADF)/cofilin family proteins are key regulators of actin filament turnover and cytoskeleton reorganization. The role of cofilin-1 in cell motility has been demonstrated in several cell types but remained poorly documented in the case of colon cancer. In addition, the putative function of destrin (also known as ADF) had not been explored in this context despite the fact that it is expressed in all colon cancer cell lines examined. We were therefore prompted to evaluate the respective contributions of these proteins to the invasive properties of the human colon cancer Isreco1 cell line, which expresses a comparatively high destrin/cofilin ratio. Reduction of cofilin-1 or destrin expression in Isreco1 cells using RNA interference led to an increase of the number of multinucleated cells and altered polarized lamellipodium protrusion and distribution of paxillin-containing adhesions. Both cofilin-1 and destrin silencing enhanced cell adhesion to extracellular matrix components. However, only destrin appeared to be required for cell migration on collagen I and for cell invasion through Matrigel in response to the proinvasive neuroendocrine peptide bombesin. This differential functional involvement was supported by a destrin-dependent, cofilin-independent phosphorylation of p130Crk-associated substrate (p130Cas) upon cell adhesion to collagen I or Matrigel. Taken together, our results suggest that destrin is a significant regulator of various processes important for invasive phenotype of human colon cancer Isreco1 cells whereas cofilin-1 may be involved in only a subset of them.
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Kostic A, Sap J, Sheetz MP. RPTPalpha is required for rigidity-dependent inhibition of extension and differentiation of hippocampal neurons. J Cell Sci 2007; 120:3895-904. [PMID: 17940065 DOI: 10.1242/jcs.009852] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Receptor-like protein tyrosine phosphatase alpha (RPTPalpha)-knockout mice have severe hippocampal abnormalities similar to knockouts of the Src family kinase Fyn. These enzymes are linked to the matrix-rigidity response in fibroblasts, but their function in neurons is unknown. The matrix-rigidity response of fibroblasts appears to differ from that of neuronal growth cones but it is unknown whether the rigidity detection mechanism or response pathway is altered. Here, we report that RPTPalpha is required for rigidity-dependent reinforcement of fibronectin (FN)-cytoskeleton bonds and the rigidity response in hippocampal neuron growth cones, like in fibroblasts. In control neurons, rigid FN surfaces inhibit neurite extension and neuron differentiation relative to soft surfaces. In RPTPalpha(-/-) neurons, no inhibition of extension and differentiation is found on both rigid and soft surfaces. The RPTPalpha-dependent rigidity response in neurons is FN-specific, and requires clustering of alpha(v)beta(6) integrin at the leading edge of the growth cones. Further, RPTPalpha is necessary for the rigidity-dependent concentration of Fyn and p130Cas phosphorylation at the leading edge of the growth cone, like it is in fibroblasts. Although neurons respond to rigid FN surfaces in the opposite way to fibroblasts, we suggest that the mechanism of detecting FN rigidity is similar and involves rigidity-dependent RPTPalpha recruitment of Fyn.
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Affiliation(s)
- Ana Kostic
- Department of Biological Sciences, Columbia University, 1212 Amsterdam Avenue, New York, NY 10027, USA
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Yadav SS, Miller WT. Cooperative activation of Src family kinases by SH3 and SH2 ligands. Cancer Lett 2007; 257:116-23. [PMID: 17719722 PMCID: PMC2045694 DOI: 10.1016/j.canlet.2007.07.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2007] [Revised: 07/06/2007] [Accepted: 07/10/2007] [Indexed: 11/21/2022]
Abstract
Src family nonreceptor tyrosine kinases are kept in a repressed state by intramolecular interactions involving the SH3 and SH2 domains of the enzymes. Ligands for these domains can displace the intramolecular associations and activate the kinases. Here, we carried out in vitro activation experiments with purified, down-regulated hematopoietic cell kinase (Hck), a Src family kinase. We show that SH3 and SH2 ligands act cooperatively to activate Src family kinases: the presence of one ligand lowers the concentration of the second ligand necessary for activation. To confirm the findings in intact cells, we studied Cas, a Src substrate that possesses SH2 and SH3 ligands. In contrast to wild-type Cas, mutant forms of Cas lacking the SH3 or SH2 ligands were unable to stimulate Src autophosphorylation when expressed in Cas-deficient fibroblasts. Cells expressing the Cas mutants also showed decreased amounts of activated Src at focal adhesions. The results suggest that proteins containing ligands for both SH3 and SH2 domains can produce a synergistic activation of Src family kinases.
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Affiliation(s)
| | - W. Todd Miller
- * To whom correspondence should be addressed: Dept. of Physiology and Biophysics, Basic Science Tower, T-6, School of Medicine, SUNY at Stony Brook, Stony Brook, NY 11794-8661, Tel.: 631-444-3533; Fax: 631-444-3432, E-mail:
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Huang Z, Yazdani U, Thompson-Peer KL, Kolodkin AL, Terman JR. Crk-associated substrate (Cas) signaling protein functions with integrins to specify axon guidance during development. Development 2007; 134:2337-47. [PMID: 17537798 DOI: 10.1242/dev.004242] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Members of the Cas family of Src homology 3 (SH3)-domain-containing cytosolic signaling proteins are crucial regulators of actin cytoskeletal dynamics in non-neuronal cells; however, their neuronal functions are poorly understood. Here, we identify a Drosophila Cas (DCas), find that Cas proteins are highly expressed in neurons and show that DCas is required for correct axon guidance during development. Functional analyses reveal that Cas specifies axon guidance by regulating the degree of fasciculation among axons. These guidance defects are similar to those observed in integrin mutants, and genetic analysis shows that integrins function together with Cas to facilitate axonal defasciculation. These results strongly support Cas proteins working together with integrins in vivo to direct axon guidance events.
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Affiliation(s)
- Zhiyu Huang
- Center for Basic Neuroscience, Department of Pharmacology, NA4.301/5323 Harry Hines Blvd, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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Bai CY, Ohsugi M, Abe Y, Yamamoto T. ZRP-1 controls Rho GTPase-mediated actin reorganization by localizing at cell-matrix and cell-cell adhesions. J Cell Sci 2007; 120:2828-37. [PMID: 17652164 DOI: 10.1242/jcs.03477] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Focal adhesion protein ZRP-1/TRIP6 has been implicated in actin reorganization and cell motility. The role of ZRP-1, however, remained obscure because previously reported data are often conflicting one another. In the present study, we examined roles of ZRP-1 in HeLa cells. ZRP-1 is localized to the cell-cell contact sites as well as to cell-matrix contact sites in HeLa cells. RNA-interference-mediated depletion of ZRP-1 from HeLa cells revealed that ZRP-1 is essential not only for the formation of stress fibers and assembly of mature focal adhesions, but also for the actin reorganization at cell-cell contact sites and for correct cell-cell adhesion and, thus, for collective cell migration. Impairment of focal adhesions and stress fibers caused by ZRP-1 depletion has been associated with reduced tyrosine phosphorylation of FAK. However, maturation of focal adhesions could not be recovered by expression of active FAK. Interestingly, stress fibers in ZRP-1-depleted cells were ameliorated by exogenous expression of RhoA. We also found that total Rac1 activity is elevated in ZRP-1-depleted cells, resulting in abnormal burst of actin polymerization and dynamic membrane protrusions. Taken together, we conclude that that ZRP-1 plays a crucial role in coupling the cell-matrix/cell-cell-contact signals with Rho GTPase-mediated actin remodeling by localizing at cell-matrix and cell-cell contact sites.
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Affiliation(s)
- Chen-Yu Bai
- Division of Oncology, Department of Cancer Biology, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
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Patwardhan P, Miller WT. Processive phosphorylation: mechanism and biological importance. Cell Signal 2007; 19:2218-26. [PMID: 17644338 PMCID: PMC2034209 DOI: 10.1016/j.cellsig.2007.06.006] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2007] [Revised: 05/31/2007] [Accepted: 06/12/2007] [Indexed: 01/13/2023]
Abstract
Recent proteomic data indicate that a majority of the phosphorylated proteins in a eucaryotic cell contain multiple sites of phosphorylation. In many signaling events, a single kinase phosphorylates multiple sites on a target protein. Processive phosphorylation occurs when a protein kinase binds once to a substrate and phosphorylates all of the available sites before dissociating. In this review, we discuss examples of processive phosphorylation by serine/threonine kinases and tyrosine kinases. We describe current experimental approaches for distinguishing processive from non-processive phosphorylation. Finally, we contrast the biological situations that are suited to regulation by processive and non-processive phosphorylation.
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Affiliation(s)
- Parag Patwardhan
- Department of Physiology and Biophysics, School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA
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Djanani A, Mosheimer B, Kaneider NC, Ross CR, Ricevuti G, Patsch JR, Wiedermann CJ. Heparan sulfate proteoglycan-dependent neutrophil chemotaxis toward PR-39 cathelicidin. JOURNAL OF INFLAMMATION-LONDON 2006; 3:14. [PMID: 17081280 PMCID: PMC1635031 DOI: 10.1186/1476-9255-3-14] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2006] [Accepted: 11/02/2006] [Indexed: 12/24/2022]
Abstract
Cathelicidins are mammalian proteins containing a C-terminal cationic antimicrobial domain. Porcine PR-39 cathelicidin affects leukocyte biology. Mechanisms of action may involve alteration of heparan sulfate proteoglycan-dependent functions in inflammatory cells. It was tested whether PR-39 affects human neutrophil migration and if such effects involve heparan sulphate proteoglycans. Neutrophils were from forearm venous blood of healthy donors. Migration was tested in modified Boyden chamber assays. Involvement of heparan sulfate proteoglycans was tested by their chemical modification and by the use of specific antibodies. PR-39 induced migration in neutrophils in a concentration dependent manner. Modification of heparan sulfate proteoglycans with sodium chlorate inhibited migration whereas chemotaxis toward the chemoattractant formyl-Met-Leu-Phe was not affected. Removal of heparan sulfates or chondroitin sulfates from the surface of neutrophils by heparinase or chondroitinase inhibited migration toward PR-39. In conclusion, antimicrobial PR-39 stimulates human neutrophil chemotaxis in a heparan sulfate proteoglycan-dependent manner. Involvment of syndecans is likely as both heparinase and chondroitinase were abrogating. Data suggest active participation of heparan sulfate proteoglycans of neutrophils in cathelicidin peptide-mediated regulation of the antimicrobial host defense.
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Affiliation(s)
- Angela Djanani
- Laboratory of Medical Intensive Care, Division of General Internal Medicine, Department of Medicine, Medical University of Innsbruck, Anichstrasse 35, A-6020 Innsbruck, Austria
| | - Birgit Mosheimer
- Laboratory of Medical Intensive Care, Division of General Internal Medicine, Department of Medicine, Medical University of Innsbruck, Anichstrasse 35, A-6020 Innsbruck, Austria
| | - Nicole C Kaneider
- Laboratory of Medical Intensive Care, Division of General Internal Medicine, Department of Medicine, Medical University of Innsbruck, Anichstrasse 35, A-6020 Innsbruck, Austria
| | - Christopher R Ross
- Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Coles Hall 228, 1600 Denison Avenue, Manhattan, KS 66506-5602, USA
| | - Giovanni Ricevuti
- Department of Internal Medicine and Therapeutics, Section of Internal Medicine, University of Pavia, Viale Liberta, I-27100 Pavia, Italy
| | - Josef R Patsch
- Laboratory of Medical Intensive Care, Division of General Internal Medicine, Department of Medicine, Medical University of Innsbruck, Anichstrasse 35, A-6020 Innsbruck, Austria
| | - Christian J Wiedermann
- Laboratory of Medical Intensive Care, Division of General Internal Medicine, Department of Medicine, Medical University of Innsbruck, Anichstrasse 35, A-6020 Innsbruck, Austria
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Patwardhan P, Shen Y, Goldberg GS, Miller WT. Individual Cas phosphorylation sites are dispensable for processive phosphorylation by Src and anchorage-independent cell growth. J Biol Chem 2006; 281:20689-20697. [PMID: 16707485 PMCID: PMC2441569 DOI: 10.1074/jbc.m602311200] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Cas is a multidomain signaling protein that resides in focal adhesions. Cas possesses a large central substrate domain containing 15 repeats of the sequence YXXP, which are phosphorylated by Src. The phosphorylation sites are essential for the roles of Cas in cell migration and in regulation of the actin cytoskeleton. We showed previously that Src catalyzes the multisite phosphorylation of Cas via a processive mechanism. In this study, we created mutant forms of Cas to identify the determinants for processive phosphorylation. Mutants containing single or multiple YXXP mutations were phosphorylated processively by Src, suggesting that individual sites are dispensable. The results also suggest that there is no defined order to the Cas phosphorylation events. We also studied the effects of these mutations by reintroducing Cas into Cas-deficient fibroblasts. Mutants lacking some or all YXXP sites augment the ability of Src to promote anchorage-independent growth. On the other hand, deletion of YXXP sites compromises the ability of Cas to promote tumor cell migration.
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Affiliation(s)
- Parag Patwardhan
- Department of Physiology and Biophysics, School of Medicine, State University of New York, Stony Brook, New York 11794
| | - Yongquan Shen
- Department of Molecular Biology, University of Medicine and Dentistry of New Jersey, Stratford, New Jersey 08084
| | - Gary S Goldberg
- Department of Molecular Biology, University of Medicine and Dentistry of New Jersey, Stratford, New Jersey 08084
| | - W Todd Miller
- Department of Physiology and Biophysics, School of Medicine, State University of New York, Stony Brook, New York 11794.
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Schmitmeier S, Markland FS, Schönthal AH, Chen TC. Potent mimicry of fibronectin-induced intracellular signaling in glioma cells by the homodimeric snake venom disintegrin contortrostatin. Neurosurgery 2006; 57:141-53; discussion 141-53. [PMID: 15987550 DOI: 10.1227/01.neu.0000163426.25227.56] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2004] [Accepted: 02/10/2005] [Indexed: 12/28/2022] Open
Abstract
OBJECTIVE The snake venom disintegrin contortrostatin (CN) is able to inhibit tumor progression and angiogenesis in vivo and therefore is of considerable interest as a potential antitumor drug. CN specifically binds to certain integrins on the tumor cell and angiogenic endothelial cell surface and inhibits their interaction with the extracellular matrix, resulting in blockage of cell motility and invasiveness. To understand the molecular consequences of CN binding to integrins, we set out to investigate and compare the effects of CN and fibronectin (FN) on integrin-induced signaling and the resulting alteration in cellular cytoskeletal morphology. METHODS Two different malignant glioma cell lines were exposed to soluble or immobilized CN, FN, or both, and the consequences for intracellular signaling and cellular adhesion to matrix were investigated. RESULTS CN binding to integrins can mimic the intracellular signaling cascade evoked by FN, because the phosphorylation of the key signaling proteins focal adhesion kinase, paxillin, and p130 Crk-associated substrate and the association of Src with focal adhesion kinase are similar. However, CN is at least one order of magnitude more potent than FN. When soluble CN is added to cells that are already attached to an FN-coated matrix, it effectively disrupts the binding of integrin to FN, leading to a decrease in integrin signaling, which, in turn, results in the disruption of the cytoskeleton and cellular detachment. CONCLUSION Our results provide a mechanistic explanation of how soluble CN might block cellular migration and invasion, namely, by disrupting and preventing the binding of integrins to the extracellular matrix. We envision that this property of CN could be used in the treatment of gliomas, namely, by intratumoral infusion of CN to prevent glioma and endothelial cell interactions with the extracellular matrix, leading to inhibition of cell invasion.
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Affiliation(s)
- Stephanie Schmitmeier
- Kenneth Norris Jr. Comprehensive Cancer Center, Department of Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, USA
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Zhang Z, Lin SY, Neel BG, Haimovich B. Phosphorylated α-Actinin and Protein-tyrosine Phosphatase 1B Coregulate the Disassembly of the Focal Adhesion Kinase·Src Complex and Promote Cell Migration. J Biol Chem 2006; 281:1746-54. [PMID: 16291744 DOI: 10.1074/jbc.m509590200] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The focal adhesion kinase (FAK) is a key regulator of cell migration. Phosphorylation at Tyr-397 activates FAK and creates a binding site for Src family kinases. FAK phosphorylates the cytoskeletal protein alpha-actinin at Tyr-12. Here we report that protein-tyrosine phosphatase 1B (PTP 1B) is an alpha-actinin phosphatase. PTP 1B-dependent dephosphorylation of alpha-actinin was seen in COS-7 cells and PTP 1B-null fibroblasts reconstituted with PTP 1B. Furthermore, we show that coexpression of wild-type alpha-actinin and PTP 1B causes dephosphorylation at Tyr-397 in FAK. No dephosphorylation was observed in cells coexpressing the alpha-actinin phosphorylation mutant Y12F and PTP 1B. Furthermore, the phosphorylation at four other sites in FAK was not altered by PTP 1B. In addition, we found that phosphorylated alpha-actinin bound to Src and reduced the binding of FAK to Src. The dephosphorylation at Tyr-397 in FAK triggered by wild-type alpha-actinin and PTP 1B caused a significant increase in cell migration. We propose that phosphorylated alpha-actinin disrupts the FAK x Src complex exposing Tyr-397 in FAK to PTP 1B. These findings uncover a novel feedback loop involving phosphorylated alpha-actinin and PTP 1B that regulates FAK x Src interaction and cell migration.
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Affiliation(s)
- Zhiyong Zhang
- Department of Surgery, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, New Brunswick 08903, USA
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Abstract
The Rho family of small GTPases are important regulators of multiple cellular activities and, most notably, reorganization of the actin cytoskeleton. Dbl-homology (DH)-domain-containing proteins are the classical guanine nucleotide exchange factors (GEFs) responsible for activation of Rho GTPases. However, members of a newly discovered family can also act as Rho-GEFs. These CZH proteins include: CDM (Ced-5, Dock180 and Myoblast city) proteins, which activate Rac; and zizimin proteins, which activate Cdc42. The family contains 11 mammalian proteins and has members in many other eukaryotes. The GEF activity is carried out by a novel, DH-unrelated domain named the DOCKER, CZH2 or DHR2 domain. CZH proteins have been implicated in cell migration, phagocytosis of apoptotic cells, T-cell activation and neurite outgrowth, and probably arose relatively early in eukaryotic evolution.
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Affiliation(s)
- Nahum Meller
- Cardiovascular Research Center, University of Virginia, Charlottesville, VA 22908, USA.
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