101
|
Mig-2 attenuates cisplatin-induced apoptosis of human glioma cells in vitro through AKT/JNK and AKT/p38 signaling pathways. Acta Pharmacol Sin 2014; 35:1199-206. [PMID: 25152024 DOI: 10.1038/aps.2014.60] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2014] [Accepted: 05/26/2014] [Indexed: 02/07/2023] Open
Abstract
AIM Mig-2 (also known as Kindlin-2 and FERMT2) is an important regulator of integrin activation and cell-extracellular matrix adhesion, and involved in carcinogenesis and tumor progression. The aim of this study was to investigate the role of mig-2 in cisplatin-induced apoptosis of human glioma cells in vitro. METHODS The expression of mig-2 was modulated in human glioma H4, HS 683 and U-87 MG cells by transfection with a plasmid carrying mig-2 or mig-2 siRNA. Cisplatin-induced apoptosis was detected using Annexin V/PI staining and flow cytometry, as well as MTS analyses. The expression of apoptosis-related or signaling proteins was examined using Western blotting analysis. H4 cells were transfected with plasmids carrying mig-2 mutants to determine the functional domain of mig-2. RESULTS In the 3 glioma cell lines tested, overexpression of mig-2 significantly attenuated cisplatin-induced apoptosis, whereas knock-down of mig-2 potentiated the apoptosis. The mechanisms of action of mig-2 were further addressed in H4 cells: overexpression of mig-2 markedly reduced cleaved caspase-9, caspase-8, caspase-3 and PARP, as well as p-JNK and p-p38, and increased p-AKT in cisplatin-treated H4 cells, whereas mig-2 siRNA reversely changed these apoptosis-related and signaling proteins. Furthermore, pretreatment with JNK inhibitor SP600125 and p38 inhibitor SB203580, or with AKT inhibitor LY294002 abolished the effects of mig-2 on cisplaxtin-induced apoptosis. In H4 cells, GFP-mig-2 F3 plasmid that contained only the F3 subdomain showed the same efficiency in attenuating cisplatin-induced apoptosis, as the mig-2 wild-type vector did, whereas GFP-mig-2 (1-541) plasmid that lacked the F3 subdomain was inactive. CONCLUSION Mig-2 significantly attenuates the antitumor action of cisplatin against human glioma cells in vitro through AKT/JNK and AKT/p38 signaling pathways. The F3 subdomain of mig-2 is necessary and sufficient for this effect.
Collapse
|
102
|
Rozario T, Mead PE, DeSimone DW. Diverse functions of kindlin/fermitin proteins during embryonic development in Xenopus laevis. Mech Dev 2014; 133:203-17. [PMID: 25173804 DOI: 10.1016/j.mod.2014.07.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 07/03/2014] [Accepted: 07/30/2014] [Indexed: 12/11/2022]
Abstract
The kindlin/fermitin family includes three proteins involved in regulating integrin ligand-binding activity and adhesion. Loss-of-function mutations in kindlins1 and 3 have been implicated in Kindler Syndrome and Leukocyte Adhesion Deficiency III (LAD-III) respectively, whereas kindlin2 null mice are embryonic lethal. Post translational regulation of cell-cell and cell-ECM adhesion has long been presumed to be important for morphogenesis, however, few specific examples of activation-dependent changes in adhesion molecule function in normal development have been reported. In this study, antisense morpholinos were used to reduce expression of individual kindlins in Xenopus laevis embryos in order to investigate their roles in early development. Kindlin1 knockdown resulted in developmental delays, gross malformations of the gut and eventual lethality by tadpole stages. Kindlin2 morphant embryos displayed late stage defects in vascular maintenance and angiogenic branching consistent with kindlin2 loss of function in the mouse. Antisense morpholinos were also used to deplete maternal kindlin2 protein in oocytes and eggs. Embryos lacking maternal kindlin2 arrested at early cleavage stages due to failures in cytokinesis. Kindlin3 morphant phenotypes included defects in epidermal ciliary beating and partial paralysis at tailbud stages but these embryos recovered eventually as morpholino levels decayed. These results indicate a remarkably diverse range of kindlin functions in vertebrate development.
Collapse
Affiliation(s)
- Tania Rozario
- Department of Cell Biology and The Morphogenesis and Regenerative Medicine Institute, University of Virginia, School of Medicine, Charlottesville, VA 22908, USA
| | - Paul E Mead
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Douglas W DeSimone
- Department of Cell Biology and The Morphogenesis and Regenerative Medicine Institute, University of Virginia, School of Medicine, Charlottesville, VA 22908, USA.
| |
Collapse
|
103
|
Fukuda K, Bledzka K, Yang J, Perera HD, Plow EF, Qin J. Molecular basis of kindlin-2 binding to integrin-linked kinase pseudokinase for regulating cell adhesion. J Biol Chem 2014; 289:28363-75. [PMID: 25160619 DOI: 10.1074/jbc.m114.596692] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Integrin-linked kinase (ILK) is a distinct intracellular adaptor essential for integrin-mediated cell-extracellular matrix adhesion, cell spreading, and migration. Acting as a major docking platform in focal adhesions, ILK engages many proteins to dynamically link integrins with the cytoskeleton, but the underlying mechanism remains elusive. Here, we have characterized the interaction of ILK with kindlin-2, a key regulator for integrin bidirectional signaling. We show that human kindlin-2 binds to human ILK with high affinity. Using systematic mapping approaches, we have identified a major ILK binding site involving a 20-residue fragment (residues 339-358) in kindlin-2. NMR-based analysis reveals a helical conformation of this fragment that utilizes its leucine-rich surface to recognize the ILK pseudokinase domain in a mode that is distinct from another ILK pseudokinase domain binding protein, α-parvin. Structure-based mutational experiments further demonstrate that the kindlin-2 binding to ILK is crucial for the kindlin-2 localization to focal adhesions and cell spreading (integrin outside-in signaling) but dispensable for the kindlin-2-mediated integrin activation (integrin inside-out signaling). These data define a specific mode of the kindlin-2/ILK interaction with mechanistic implications as to how it spatiotemporally mediates integrin signaling and cell adhesion.
Collapse
Affiliation(s)
- Koichi Fukuda
- From the Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Kamila Bledzka
- From the Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Jun Yang
- From the Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - H Dhanuja Perera
- From the Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Edward F Plow
- From the Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Jun Qin
- From the Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| |
Collapse
|
104
|
Documentation and localization of force-mediated filamin A domain perturbations in moving cells. Nat Commun 2014; 5:4656. [PMID: 25120197 PMCID: PMC4139033 DOI: 10.1038/ncomms5656] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 07/10/2014] [Indexed: 12/15/2022] Open
Abstract
Endogenously and externally generated mechanical forces influence diverse cellular activities, a phenomenon defined as mechanotransduction. Deformation of protein domains by application of stress, previously documented to alter macromolecular interactions in vitro, could mediate these effects. We engineered a photon-emitting system responsive to unfolding of two repeat domains of the actin filament (F-actin) crosslinker protein filamin A (FLNA) that binds multiple partners involved in cell signalling reactions and validated the system using F-actin networks subjected to myosin-based contraction. Expressed in cultured cells, the sensor-containing FLNA construct reproducibly reported FLNA domain unfolding strikingly localized to dynamic, actively protruding, leading cell edges. The unfolding signal depends upon coherence of F-actin-FLNA networks and is enhanced by stimulating cell contractility. The results establish protein domain distortion as a bona fide mechanism for mechanotransduction in vivo.
Collapse
|
105
|
Brunetti-Pierri N, Torrado M, Fernandez MDC, Tello AM, Arberas CL, Cardinale A, Piccolo P, Bacino CA. Terminal osseous dysplasia with pigmentary defects (TODPD) due to a recurrent filamin A (FLNA) mutation. Mol Genet Genomic Med 2014; 2:467-71. [PMID: 25614868 PMCID: PMC4303216 DOI: 10.1002/mgg3.90] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 05/01/2014] [Accepted: 05/08/2014] [Indexed: 12/01/2022] Open
Abstract
Terminal osseous dysplasia with pigmentary defects (TODPD) is an X-linked dominant syndrome with distal limb anomalies, pigmentary skin defects, digital fibromas, and generalized bone involvement due to a recurrent mutation in the filamin A (FLNA) gene. We here report the mutation c.5217G>A in FLNA in three families with TODPD and we found possible germline and somatic mosaicism in two out of the three families. The occurrence of somatic and germline mosaicism for TODPD indicates that caution should be taken in counseling recurrence risks for these conditions upon presentation of an isolated case.
Collapse
Affiliation(s)
- Nicola Brunetti-Pierri
- Telethon Institute of Genetics and Medicine Naples, Italy ; Department of Translational Medicine, Federico II University of Naples Naples, Italy
| | - Maria Torrado
- Servicio de Genética, Hospital Garraham Buenos Aires, Argentina
| | | | - Ana Maria Tello
- Hospital de Niños Dr. Ricardo Gutiérrez Buenos Aires, Argentina
| | | | | | | | - Carlos A Bacino
- Department of Molecular and Human Genetics, Baylor College of Medicine Houston, Texas
| |
Collapse
|
106
|
Bachir AI, Zareno J, Moissoglu K, Plow EF, Gratton E, Horwitz AR. Integrin-associated complexes form hierarchically with variable stoichiometry in nascent adhesions. Curr Biol 2014; 24:1845-53. [PMID: 25088556 DOI: 10.1016/j.cub.2014.07.011] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 06/03/2014] [Accepted: 07/04/2014] [Indexed: 12/18/2022]
Abstract
BACKGROUND A complex network of putative molecular interactions underlies the architecture and function of cell-matrix adhesions. Most of these interactions are implicated from coimmunoprecipitation studies using expressed components, but few have been demonstrated or characterized functionally in living cells. RESULTS We introduce fluorescence fluctuation methods to determine, at high spatial and temporal resolution, "when" and "where" molecular complexes form and their stoichiometry in nascent adhesions (NAs). We focus on integrin-associated molecules implicated in integrin activation and in the integrin-actin linkage in NAs and show that these molecules form integrin-containing complexes hierarchically within the adhesion itself. Integrin and kindlin reside in a molecular complex as soon as adhesions are visible; talin, although also present early, associates with the integrin-kindlin complex only after NAs have formed and in response to myosin II activity. Furthermore, talin and vinculin association precedes the formation of the integrin-talin complex. Finally, α-actinin enters NAs periodically and in clusters that transiently associate with integrins. The absolute number and stoichiometry of these molecules varies among the molecules studied and changes as adhesions mature. CONCLUSIONS These observations suggest a working model for NA assembly whereby transient α-actinin-integrin complexes help nucleate NAs within the lamellipodium. Subsequently, integrin complexes containing kindlin, but not talin, emerge. Once NAs have formed, myosin II activity promotes talin association with the integrin-kindlin complex in a stoichiometry consistent with each talin molecule linking two integrin-kindlin complexes.
Collapse
Affiliation(s)
- Alexia I Bachir
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22908, USA.
| | - Jessica Zareno
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22908, USA
| | - Konstadinos Moissoglu
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Edward F Plow
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Enrico Gratton
- Laboratory of Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697, USA
| | - Alan R Horwitz
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22908, USA
| |
Collapse
|
107
|
Papsdorf K, Sacherl J, Richter K. The balanced regulation of Hsc70 by DNJ-13 and UNC-23 is required for muscle functionality. J Biol Chem 2014; 289:25250-61. [PMID: 25053410 DOI: 10.1074/jbc.m114.565234] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The molecular chaperone Hsc70 assists in the folding of non-native proteins together with its J domain- and BAG domain-containing cofactors. In Caenorhabditis elegans, two BAG domain-containing proteins can be identified, one of them being UNC-23, whose mutation induces severe motility dysfunctions. Using reporter strains, we find that the full-length UNC-23, in contrast to C-terminal fragments, localizes specifically to the muscular attachment sites. C-terminal fragments of UNC-23 instead perform all Hsc70-related functions, like ATPase stimulation and regulation of folding activity, albeit with lower affinity than BAG-1. Interestingly, overexpression of CFP-Hsc70 can induce muscular defects in wild-type nematodes that phenocopy the knockout of its cofactor UNC-23. Strikingly, the motility dysfunction in the unc-23 mutated strain can be cured specifically by down-regulation of the antagonistic Hsc70 cochaperone DNJ-13, implying that the severe phenotype is caused by misregulation of the Hsc70 cycle. These findings point out that the balanced action of cofactors in the ATP-driven cycle of Hsc70 is crucial for the contribution of Hsc70 to muscle functionality.
Collapse
Affiliation(s)
- Katharina Papsdorf
- From the Department of Biotechnology and Center for Integrated Protein Science Munich (CIPS), Technische Universität München, Lichtenbergstrasse 4, 85748 Garching, Germany
| | - Julia Sacherl
- From the Department of Biotechnology and Center for Integrated Protein Science Munich (CIPS), Technische Universität München, Lichtenbergstrasse 4, 85748 Garching, Germany
| | - Klaus Richter
- From the Department of Biotechnology and Center for Integrated Protein Science Munich (CIPS), Technische Universität München, Lichtenbergstrasse 4, 85748 Garching, Germany
| |
Collapse
|
108
|
Liu Z, Zhan Y, Tu Y, Chen K, Liu Z, Wu C. PDZ and LIM domain protein 1(PDLIM1)/CLP36 promotes breast cancer cell migration, invasion and metastasis through interaction with α-actinin. Oncogene 2014; 34:1300-11. [PMID: 24662836 PMCID: PMC4175366 DOI: 10.1038/onc.2014.64] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 02/10/2014] [Accepted: 02/16/2014] [Indexed: 12/19/2022]
Abstract
Increased CLP36 expression has been found to be closely associated with breast cancer progression. However, whether and how it contributes to malignant behavior of breast cancer cells were not known. We show here that CLP36 is critical for promoting breast cancer cell migration and invasion in vitro and metastasis in vivo, whereas it is dispensable for breast cell proliferation and anchorage independent growth in vitro and tumor growth in vivo. CLP36 interacted with both α-actinin-1 and -4 in breast cancer cells. Depletion of either α-actinin-1 or -4 inhibited breast cancer cell migration. Furthermore, mutations inhibiting the α-actinin-binding activity abolished the ability of CLP36 to promote breast cancer cell migration. Finally, depletion of CLP36 or disruption of the CLP36-α-actinin complex in breast cancer cells substantially inhibited Cdc42 activation, cell polarization and migration. Our results identify CLP36 as an important regulator of breast cancer cell migration and metastasis, and shed light on how increased CLP36 expression contributes to progression of breast cancer.
Collapse
Affiliation(s)
- Z Liu
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Y Zhan
- State Key Laboratory of Molecular Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Y Tu
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - K Chen
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Z Liu
- State Key Laboratory of Molecular Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - C Wu
- 1] Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA [2] University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA
| |
Collapse
|
109
|
Zhang HF, Zhang K, Liao LD, Li LY, Du ZP, Wu BL, Wu JY, Xu XE, Zeng FM, Chen B, Cao HH, Zhu MX, Dai LH, Long L, Wu ZY, Lai R, Xu LY, Li EM. miR-200b suppresses invasiveness and modulates the cytoskeletal and adhesive machinery in esophageal squamous cell carcinoma cells via targeting Kindlin-2. Carcinogenesis 2014; 35:292-301. [PMID: 24064224 DOI: 10.1093/carcin/bgt320] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
To further our understanding of the pathobiology of esophageal squamous cell carcinoma (ESCC), we previously performed microRNA profiling that revealed downregulation of miR-200b in ESCC. Using quantitative real-time PCR applied to 88 patient samples, we confirmed that ESCC tumors expressed significantly lower levels of miR-200b compared with the respective adjacent benign tissues (P = 0.003). Importantly, downregulation of miR-200b significantly correlated with shortened survival (P = 0.025), lymph node metastasis (P = 0.002) and advanced clinical stage (P = 0.020) in ESCC patients. Quantitative mass spectrometry identified 57 putative miR-200b targets, including Kindlin-2, previously implicated in the regulation of tumor invasiveness and actin cytoskeleton in other cell types. Enforced expression of miR-200b mimic in ESCC cells led to a decrease of Kindlin-2 expression, whereas transfection of miR-200b inhibitor induced Kindlin-2 expression. Furthermore, transfection of miR-200b mimic or knockdown of Kindlin-2 in ESCC cells decreased cell protrusion and focal adhesion (FA) formation, reduced cell spreading and invasiveness/migration. Enforced expression of Kindlin-2 largely abrogated the inhibitory effects of miR-200b on ESCC cell invasiveness. Mechanistic studies revealed that Rho-family guanosine triphosphatases and FA kinase mediated the biological effects of the miR-200b-Kindlin-2 axis in ESCC cells. To conclude, loss of miR-200b, a frequent biochemical defect in ESCC, correlates with aggressive clinical features. The tumor suppressor effects of miR-200b may be due to its suppression of Kindlin-2, a novel target of miR-200b that modulates actin cytoskeleton, FA formation and the migratory/invasiveness properties of ESCC.
Collapse
Affiliation(s)
- Hai-Feng Zhang
- Department of Biochemistry and Molecular Biology, The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou, Guangdong 515041, China
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
110
|
Ye F, Snider AK, Ginsberg MH. Talin and kindlin: the one-two punch in integrin activation. Front Med 2014; 8:6-16. [DOI: 10.1007/s11684-014-0317-3] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 11/29/2013] [Indexed: 11/25/2022]
|
111
|
Abstract
Integrins are heterodimeric cell surface adhesion receptors essential for multicellular life. They connect cells to the extracellular environment and transduce chemical and mechanical signals to and from the cell. Intracellular proteins that bind the integrin cytoplasmic tail regulate integrin engagement of extracellular ligands as well as integrin localization and trafficking. Cytoplasmic integrin-binding proteins also function downstream of integrins, mediating links to the cytoskeleton and to signaling cascades that impact cell motility, growth, and survival. Here, we review key integrin-interacting proteins and their roles in regulating integrin activity, localization, and signaling.
Collapse
Affiliation(s)
- Elizabeth M Morse
- Department of Cell Biology and ‡Department of Pharmacology, Yale University School of Medicine , 333 Cedar Street, New Haven, Connecticut 06520, United States
| | | | | |
Collapse
|
112
|
Lennon R, Randles MJ, Humphries MJ. The importance of podocyte adhesion for a healthy glomerulus. Front Endocrinol (Lausanne) 2014; 5:160. [PMID: 25352829 PMCID: PMC4196579 DOI: 10.3389/fendo.2014.00160] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 09/21/2014] [Indexed: 12/23/2022] Open
Abstract
Podocytes are specialized epithelial cells that cover the outer surfaces of glomerular capillaries. Unique cell junctions, known as slit diaphragms, which feature nephrin and Neph family proteins in addition to components of adherens, tight, and gap junctions, connect adjacent podocyte foot processes. Single gene disorders affecting the slit diaphragm result in nephrotic syndrome in humans, characterized by massive loss of protein across the capillary wall. In addition to specialized cell junctions, interconnecting podocytes also adhere to the glomerular basement membrane (GBM) of the capillary wall. The GBM is a dense network of secreted, extracellular matrix (ECM) components and contains tissue-restricted isoforms of collagen IV and laminin in addition to other structural proteins and ECM regulators such as proteases and growth factors. The specialized niche of the GBM provides a scaffold for endothelial cells and podocytes to support their unique functions and human genetic mutations in GBM components lead to renal failure, thus highlighting the importance of cell-matrix interactions in the glomerulus. Cells adhere to ECM via adhesion receptors, including integrins, syndecans, and dystroglycan and in particular the integrin heterodimer α3β1 is required to maintain barrier integrity. Therefore, the sophisticated function of glomerular filtration relies on podocyte adhesion both at cell junctions and at the interface with the ECM. In health, the podocyte coordinates signals from cell junctions and cell-matrix interactions, in response to environmental cues in order to regulate filtration and as our understanding of mechanisms that control cell adhesion in the glomerulus develops, then insight into the effects of disease will improve. The ultimate goal will be to develop targeted therapies to prevent or repair defects in the filtration barrier and to restore glomerular function.
Collapse
Affiliation(s)
- Rachel Lennon
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, The University of Manchester, Manchester, UK
- Institute of Human Development, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, UK
- Department of Paediatric Nephrology, Manchester Academic Health Science Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester, UK
- *Correspondence: Rachel Lennon, Wellcome Trust Centre for Cell-Matrix Research, The University of Manchester, Michael Smith Building, Manchester M13 9PT, UK e-mail:
| | - Michael J. Randles
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, The University of Manchester, Manchester, UK
- Institute of Human Development, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, UK
| | - Martin J. Humphries
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, The University of Manchester, Manchester, UK
| |
Collapse
|
113
|
Kuo JC. Focal adhesions function as a mechanosensor. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 126:55-73. [PMID: 25081614 DOI: 10.1016/b978-0-12-394624-9.00003-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Focal adhesions (FAs) are complex plasma membrane-associated macromolecular assemblies that engage with the surrounding extracellular matrix (ECM) via integrin receptors and physically connect with the actin cytoskeleton through the recruitment of numerous FA-associated proteins. FAs undergo a maturation process, which is known to be induced by biochemical or physical cues, to grow and change composition. Varying FA size, distribution, dynamics, and compositions during maturation process is required for transducing the specific signaling networks that reflect the requirements of a cell to sense, adapt, and response to a variety of the environments. While advances have been demonstrated in understanding how important FAs are in mediating various biological processes, less is known about how FA composition is regulated and coordinately transduces the specific signals in mediating the distinct biological outcomes, especially cell migration.
Collapse
Affiliation(s)
- Jean-Cheng Kuo
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei, Taiwan
| |
Collapse
|
114
|
Yang M, Du J, Lu D, Ren C, Shen H, Qiao J, Chen X, Zhang H. Increased expression of kindlin 2 in luteinized granulosa cells correlates with androgen receptor level in patients with polycystic ovary syndrome having hyperandrogenemia. Reprod Sci 2013; 21:696-703. [PMID: 24336678 DOI: 10.1177/1933719113512536] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Hyperandrogenemia is the leading defect in patients with polycystic ovary syndrome (PCOS) and considered to be involved in the ovulation dysfunction of PCOS. During the process of ovulation, granulosa cells (GCs) undergo epithelial-mesenchymal transition (EMT), and integrin-interacting protein kindlin 2 is a well-known regulator in EMT. Therefore, our objective here was to compare the expression levels of kindlin 2 in luteinized GCs between patients with PCOS and control women and the relationship between kindlin 2 and PCOS pathogenesis. In this study, kindlin 2 expression was significantly increased in luteinized GCs from patients with PCOS, and kindlin 2 could be induced by testosterone both in vitro and in vivo. Meanwhile, kindlin 2 was positively correlated with androgen receptor (AR) in PCOS GCs. Taken together, kindlin 2 may play a role in luteinized GCs, especially in the case of excess androgen. Further studies are required to assess the specific role of kindlin 2 in follicular development and PCOS pathogenesis.
Collapse
Affiliation(s)
- Mei Yang
- 1Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education, and Laboratory of Stem Cell, Development and Reproductive Medicine, Department of Anatomy, Histology and Embryology, Peking University Health Science Center, Beijing, China
| | | | | | | | | | | | | | | |
Collapse
|
115
|
Ye F, Petrich BG, Anekal P, Lefort CT, Kasirer-Friede A, Shattil SJ, Ruppert R, Moser M, Fässler R, Ginsberg MH. The mechanism of kindlin-mediated activation of integrin αIIbβ3. Curr Biol 2013; 23:2288-2295. [PMID: 24210614 DOI: 10.1016/j.cub.2013.09.050] [Citation(s) in RCA: 122] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 08/30/2013] [Accepted: 09/24/2013] [Indexed: 01/11/2023]
Abstract
Increased ligand binding to cellular integrins ("activation") plays important roles in processes such as development, cell migration, extracellular matrix assembly, tumor metastasis, hemostasis, and thrombosis. Integrin activation encompasses both increased integrin monomer affinity and increased receptor clustering and depends on integrin-talin interactions. Loss of kindlins results in reduced activation of integrins. Kindlins might promote talin binding to integrins through a cooperative mechanism; however, kindlins do not increase talin association with integrins. Here, we report that, unlike talin head domain (THD), kindlin-3 has little effect on the affinity of purified monomeric αIIbβ3, and it does not enhance activation by THD. Furthermore, studies with ligands of varying valency show that kindlins primarily increase cellular αIIbβ3 avidity rather than monomer affinity. In platelets or nucleated cells, loss of kindlins markedly reduces αIIbβ3 binding to multivalent but not monovalent ligands. Finally, silencing of kindlins reduces the clustering of ligand-occupied αIIbβ3 as revealed by total internal reflection fluorescence and electron microscopy. Thus, in contrast to talins, kindlins have little primary effect on integrin αIIbβ3 affinity for monovalent ligands and increase multivalent ligand binding by promoting the clustering of talin-activated integrins.
Collapse
Affiliation(s)
- Feng Ye
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Brian G Petrich
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Praju Anekal
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Craig T Lefort
- La Jolla Institute for Allergy & Immunology, La Jolla, CA 92093, USA
| | - Ana Kasirer-Friede
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Sanford J Shattil
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Raphael Ruppert
- Department of Molecular Medicine, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Markus Moser
- Department of Molecular Medicine, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Reinhard Fässler
- Department of Molecular Medicine, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Mark H Ginsberg
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
| |
Collapse
|
116
|
Brahme NN, Harburger DS, Kemp-O'Brien K, Stewart R, Raghavan S, Parsons M, Calderwood DA. Kindlin binds migfilin tandem LIM domains and regulates migfilin focal adhesion localization and recruitment dynamics. J Biol Chem 2013; 288:35604-16. [PMID: 24165133 DOI: 10.1074/jbc.m113.483016] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Focal adhesions (FAs), sites of tight adhesion to the extracellular matrix, are composed of clusters of transmembrane integrin adhesion receptors and intracellular proteins that link integrins to the actin cytoskeleton and signaling pathways. Two integrin-binding proteins present in FAs, kindlin-1 and kindlin-2, are important for integrin activation, FA formation, and signaling. Migfilin, originally identified in a yeast two-hybrid screen for kindlin-2-interacting proteins, is a LIM domain-containing adaptor protein found in FAs and implicated in control of cell adhesion, spreading, and migration. By binding filamin, migfilin provides a link between kindlin and the actin cytoskeleton. Here, using a combination of kindlin knockdown, biochemical pulldown assays, fluorescence microscopy, fluorescence resonance energy transfer (FRET), and fluorescence recovery after photobleaching (FRAP), we have established that the C-terminal LIM domains of migfilin dictate its FA localization, shown that these domains mediate an interaction with kindlin in vitro and in cells, and demonstrated that kindlin is important for normal migfilin dynamics in cells. We also show that when the C-terminal LIM domain region is deleted, then the N-terminal filamin-binding region of the protein, which is capable of targeting migfilin to actin-rich stress fibers, is the predominant driver of migfilin localization. Our work details a correlation between migfilin domains that drive kindlin binding and those that drive FA localization as well as a kindlin dependence on migfilin FA recruitment and mobility. We therefore suggest that the kindlin interaction with migfilin LIM domains drives migfilin FA recruitment, localization, and mobility.
Collapse
|
117
|
Shen Z, Ye Y, Kauttu T, Seppänen H, Vainionpää S, Wang S, Mustonen H, Puolakkainen P. Novel focal adhesion protein kindlin-2 promotes the invasion of gastric cancer cells through phosphorylation of integrin β1 and β3. J Surg Oncol 2013; 108:106-12. [PMID: 23857544 DOI: 10.1002/jso.23353] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 04/23/2013] [Indexed: 01/07/2023]
Abstract
BACKGROUND We have found that the expression of the novel focal adhesion protein kindlin-2 had a significant positive correlation with poor survival in gastric cancer. However, the mechanism by which kindlin-2 acts in gastric cancer warrants further evaluation. METHODS Kindlin-2 mRNA expression in gastric cancer cell lines was measured by realtime RT-PCR under normal and hypoxic conditions. Cell proliferation, apoptosis, cell cycle, tumor adhesion, cell invasion ability, and phosphorylation of integrin β1 and β3 proteins were measured to assess the influence of kindlin-2 on the malignant behavior of gastric cancer cells. RESULTS Kindlin-2 mRNA expression was highest in the distant metastasis gastric cancer cell line Hs-746T. Cell proliferation, adhesion with endothelium and collagen IV, invasion rate, and angiogenesis genes expression, as well as phosphorylation of integrin β1 and β3 in Hs-746T, were decreased significantly after kindlin-2 downregulation, but there was no change in apoptosis and cell cycle. CONCLUSIONS Kindlin-2 might promote the invasion of gastric cancer cells through enhancing proliferation and adhesion by the phosphorylation of integrin β1 and β3.
Collapse
Affiliation(s)
- Zhanlong Shen
- Department of Gastroenterological Surgery, Peking University People's Hospital, Beijing, PR China.
| | | | | | | | | | | | | | | |
Collapse
|
118
|
Seerapu HR, Borthakur S, Kong N, Agrawal S, Drazba J, Vasanji A, Fantin A, Ruhrberg C, Buck M, Horowitz A. The cytoplasmic domain of neuropilin-1 regulates focal adhesion turnover. FEBS Lett 2013; 587:3392-9. [PMID: 24021649 DOI: 10.1016/j.febslet.2013.08.040] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 08/26/2013] [Indexed: 01/13/2023]
Abstract
Though the vascular endothelial growth factor coreceptor neuropilin-1 (Nrp1) plays a critical role in vascular development, its precise function is not fully understood. We identified a group of novel binding partners of the cytoplasmic domain of Nrp1 that includes the focal adhesion regulator, Filamin A (FlnA). Endothelial cells (ECs) expressing a Nrp1 mutant devoid of the cytoplasmic domain (nrp1(cyto)(Δ/Δ)) migrated significantly slower in response to VEGF relative to the cells expressing wild-type Nrp1 (nrp1(+/+) cells). The rate of FA turnover in VEGF-treated nrp1(cyto)(Δ/Δ) ECs was an order of magnitude lower in comparison to nrp1(+/+) ECs, thus accounting for the slower migration rate of the nrp1(cyto)(Δ/Δ) ECs.
Collapse
Affiliation(s)
- Himabindu Reddy Seerapu
- Department of Molecular Cardiology, Lerner Research Institute, the Cleveland Clinic, Cleveland, OH 44195, United States
| | | | | | | | | | | | | | | | | | | |
Collapse
|
119
|
Singh S, More KR, Chitnis CE. Role of calcineurin and actin dynamics in regulated secretion of microneme proteins in Plasmodium falciparum merozoites during erythrocyte invasion. Cell Microbiol 2013; 16:50-63. [PMID: 23910910 DOI: 10.1111/cmi.12177] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 07/16/2013] [Accepted: 07/30/2013] [Indexed: 11/28/2022]
Abstract
Plasmodium falciparum invades host erythrocytes by multiple invasion pathways. The invasion of erythrocytes by P. falciparum merozoites is a complex process that requires multiple interactions between host receptors and parasite ligands. A number of parasite proteins that mediate interaction with host receptors during invasion are localized to membrane-bound apical organelles referred to as micronemes and rhoptries. The timely release of these proteins to the merozoite surface is crucial for receptor engagement and invasion. It has been demonstrated previously that exposure of merozoites to a low potassium (K(+)) ionic environment as found in blood plasma leads to a rise in cytosolic calcium (Ca(2+)), which triggers microneme secretion. The signalling pathways that regulate microneme discharge in response to rise in cytosolic Ca(2+) are not completely understood. Here, we show that a P. falciparum Ca(2+)-dependent protein phosphatase, calcineurin (PfCN), is an essential regulator of Ca(2+)-dependent microneme exocytosis. An increase in PfCN activity was observed in merozoites following exposure to a low K(+) environment. Treatment of merozoites with calcineurin inhibitors such as FK506 and cyclosporin A prior to transfer to a low K(+) environment resulted in inhibition of secretion of microneme protein apical merozoite antigen-1 (PfAMA-1). Inhibition of PfCN was shown to result in reduced dephosphorylation and depolymerization of apical actin, which appears to be criticalfor microneme secretion. PfCN thus serves as an effector of Ca(2+)-dependent microneme exocytosis by regulating depolymerization of apical actin. Inhibitors that target PfCN block microneme exocytosis and limit growth of P. falciparum blood-stage parasites providing a novel approach towards development of new therapeutic strategies against malaria.
Collapse
Affiliation(s)
- Shailja Singh
- International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
| | | | | |
Collapse
|
120
|
Schiller HB, Fässler R. Mechanosensitivity and compositional dynamics of cell-matrix adhesions. EMBO Rep 2013; 14:509-19. [PMID: 23681438 DOI: 10.1038/embor.2013.49] [Citation(s) in RCA: 202] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 03/21/2013] [Indexed: 12/27/2022] Open
Abstract
Cells perceive information about the biochemical and biophysical properties of their tissue microenvironment through integrin-mediated cell-matrix adhesions, which connect the cytoskeleton with the extracellular matrix and thereby allow cohesion and long-range mechanical connections within tissues. The formation of cell-matrix adhesions and integrin signalling involves the dynamic recruitment and assembly of an inventory of proteins, collectively termed the 'adhesome', at the adhesive site. The recruitment of some adhesome proteins, most notably the Lin11-, Isl1- and Mec3-domain-containing proteins, depends on mechanical tension generated by myosin II-mediated contractile forces exerted on cell-matrix adhesions. When exposed to force, mechanosensitive adhesome proteins can change their conformation or expose cryptic-binding sites leading to the recruitment of proteins, rearrangement of the cytoskeleton, reinforcement of the adhesive site and signal transduction. Biophysical methods and proteomics revealed force ranges within the adhesome and cytoskeleton, and also force-dependent changes in adhesome composition. In this review, we provide an overview of the compositional dynamics of cell-matrix adhesions, discuss the most prevalent functional domains in adhesome proteins and review literature and concepts about mechanosensing mechanisms that operate at the adhesion site.
Collapse
Affiliation(s)
- Herbert B Schiller
- Department of Molecular Medicine, Max Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany
| | | |
Collapse
|
121
|
Xu Z, Gao J, Hong J, Ma YQ. Integrity of kindlin-2 FERM subdomains is required for supporting integrin activation. Biochem Biophys Res Commun 2013; 434:382-7. [PMID: 23578664 DOI: 10.1016/j.bbrc.2013.03.086] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 03/31/2013] [Indexed: 11/19/2022]
Abstract
Kindlin family members are essential for supporting integrin activation by functionally cooperating with the talin head domain. Both the talin head and kindlin are FERM domain-containing proteins that can simultaneously interact with the integrin β cytoplasmic tails. While the talin head is well studied, the molecular basis of kindlin's interaction with integrin during integrin activation is still poorly understood. Here we defined the subdomain boundaries in kindlin-2 and evaluated their contribution to integrin activation and recognition. We found that each subdomain in kindlin-2 was required for co-activating the integrin αIIbβ3 together with the talin head (inside-out signaling) and for enhancing integrin αIIbβ3-mediated cell spreading (outside-in signaling). To evaluate the involvement of the kindlin-2 subdomains in integrin interaction, we developed a FACS-based binding assay and found that an intact FERM domain in kindlin-2 was required for the interaction. Taking all together, these findings suggest that the integrity of kindlin-2 subdomains is a prerequisite for supporting integrin recognition and for subsequent integrin activation.
Collapse
Affiliation(s)
- Zhen Xu
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, WI 53226, USA
| | | | | | | |
Collapse
|
122
|
Mahawithitwong P, Ohuchida K, Ikenaga N, Fujita H, Zhao M, Kozono S, Shindo K, Ohtsuka T, Mizumoto K, Tanaka M. Kindlin-2 expression in peritumoral stroma is associated with poor prognosis in pancreatic ductal adenocarcinoma. Pancreas 2013; 42:663-9. [PMID: 23508013 DOI: 10.1097/mpa.0b013e318279bd66] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVES Kindlin-2 is a novel focal adhesion protein reported to be expressed in breast, lung, and gastric cancers. This study aimed to investigate the significance of kindlin-2 expression in pancreatic ductal adenocarcinomas (PDACs). METHODS We performed immunohistochemical analysis on kindlin-2 on PDAC samples from 95 patients. We investigated the association between kindlin-2 expression and clinicopathological parameters of PDAC and the survival time of patients with PDAC who underwent pancreatectomy. RESULTS Kindlin-2 was highly expressed in the peritumoral stroma of PDACs. Stromal kindlin-2 expression was related to nodal metastasis (P = 0.03). Univariate analysis showed that patients with positive kindlin-2 expression had significantly shorter survival times than those with negative kindlin-2 expression (P = 0.01). In addition, multivariate analysis revealed that kindlin-2 expression was an independent factor of poor prognosis in patients with PDAC after R0 resection (RR = 2.15; P = 0.04). CONCLUSIONS Kindlin-2 expression in stromal components is significantly associated with poor prognosis of patients with PDAC, suggesting that kindlin-2 is a prognostic marker for patients with PDAC.
Collapse
MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Biomarkers, Tumor/genetics
- Biomarkers, Tumor/metabolism
- Carcinoma, Pancreatic Ductal/genetics
- Carcinoma, Pancreatic Ductal/metabolism
- Carcinoma, Pancreatic Ductal/pathology
- Cell Line, Tumor
- Female
- Humans
- Male
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Middle Aged
- Multivariate Analysis
- Neoplasm Proteins/genetics
- Neoplasm Proteins/metabolism
- Pancreatic Neoplasms/genetics
- Pancreatic Neoplasms/metabolism
- Pancreatic Neoplasms/pathology
- Prognosis
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Neoplasm/genetics
- RNA, Neoplasm/metabolism
- Stromal Cells/metabolism
- Stromal Cells/pathology
Collapse
|
123
|
Yu Y, Wu J, Guan L, Qi L, Tang Y, Ma B, Zhan J, Wang Y, Fang W, Zhang H. Kindlin 2 promotes breast cancer invasion via epigenetic silencing of the microRNA200 gene family. Int J Cancer 2013; 133:1368-79. [PMID: 23483548 DOI: 10.1002/ijc.28151] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 02/20/2013] [Indexed: 02/06/2023]
Abstract
Kindlin 2, as a focal adhesion protein, controls integrin activation and regulates Wnt signaling in an integrin-binding independent manner. However, the association of Kindlin 2 with cancer-related microRNAs is unknown. Here, we report that Kindlin 2 markedly downregulates the expression of miR-200 family by inducing CpG island hypermethylation. Mechanistically, Kindlin 2 forms a complex with DNMT3A in the cell nucleus and the two proteins co-occupy the promoter of miRNA-200b. Functionally, repression of miR-200b is required for Kindlin 2-induced breast cancer cell invasion and tumor formation. Our data indicate that Kindlin 2 plays a novel role in epigenetic repression of miR-200 family, a mechanism that promotes breast cancer invasion.
Collapse
Affiliation(s)
- Yu Yu
- Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education of China, Peking University Health Science Center, Beijing, 100191, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
124
|
Kuo JC. Mechanotransduction at focal adhesions: integrating cytoskeletal mechanics in migrating cells. J Cell Mol Med 2013; 17:704-12. [PMID: 23551528 PMCID: PMC3823174 DOI: 10.1111/jcmm.12054] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2012] [Accepted: 02/25/2013] [Indexed: 12/22/2022] Open
Abstract
Focal adhesions (FAs) are complex plasma membrane-associated macromolecular assemblies that serve to physically connect the actin cytoskeleton to integrins that engage with the surrounding extracellular matrix (ECM). FAs undergo maturation wherein they grow and change composition differentially to provide traction and to transduce the signals that drive cell migration, which is crucial to various biological processes, including development, wound healing and cancer metastasis. FA-related signalling networks dynamically modulate the strength of the linkage between integrin and actin and control the organization of the actin cytoskeleton. In this review, we have summarized a number of recent investigations exploring how FA composition is affected by the mechanical forces that transduce signalling networks to modulate cellular function and drive cell migration. Understanding the fundamental mechanisms of how force governs adhesion signalling provides insights that will allow the manipulation of cell migration and help to control migration-related human diseases.
Collapse
Affiliation(s)
- Jean-Cheng Kuo
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei, Taiwan.
| |
Collapse
|
125
|
Zhao T, Guan L, Yu Y, Pei X, Zhan J, Han L, Tang Y, Li F, Fang W, Zhang H. Kindlin-2 promotes genome instability in breast cancer cells. Cancer Lett 2013; 330:208-16. [DOI: 10.1016/j.canlet.2012.11.043] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 11/26/2012] [Accepted: 11/27/2012] [Indexed: 12/31/2022]
|
126
|
Mohammed AES, Eguchi H, Wada S, Koyama N, Shimizu M, Otani K, Ohtaki M, Tanimoto K, Hiyama K, Gaber MS, Nishiyama M. TMEM158 and FBLP1 as novel marker genes of cisplatin sensitivity in non-small cell lung cancer cells. Exp Lung Res 2013; 38:463-74. [PMID: 23098063 DOI: 10.3109/01902148.2012.731625] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Even after development of molecular targeting therapies, platinum-based chemotherapy is still a standard care for treatment of locally advanced non-small cell lung cancer (NSCLC). So far, critical molecular markers capable to predict the therapeutic response in NSCLC patients remain undetermined. We here attempted to identify novel biomarker genes for cisplatin (CDDP) for a tailored therapy. Initial screening to explorer association of IC(50) values of CDDP obtained by MTT assay and gene expression levels measured with oligonucleotide microarray and real-time RT-PCR provided 6 candidate genes, namely, NUBPL, C9orf30, ZNF12, TMEM158, GSK3B, and FBLP1 using 9 lung cancer cells consisting of 3 small and 6 NSCLC cells. These 6 genes together with 5 reported biomarkers, i.e., GSTP1, ERCC1, BRCA1, FRAP1, and RRM1, were subjected to a linear regression analysis using 12 NSCLC cell lines including 6 additional NSCLC cells: only FBLP1 and TMEM158 genes showed positive associations with statistical significances (P = .016 and .026, respectively). The biological significance of these genes was explored by in vitro experiments: Knockdown experiments in PC-9/CDDP cells revealed that the reduced expression of TMEM158 significantly decreased the chemo-resistance against CDDP (P <.0001), while 2 transformants of PC-6 cells stably over-expressing FBLP1 resulted in an enhanced resistance to CDDP (P = .004 and P = .001). Furthermore, a stepwise multiple regression analysis demonstrated the best prediction formula could be fixed when we used expression data of TMEM158 and FBLP1 (R(2) = 0.755, P = .0018). TMEM158 and FBLP1 may be powerful predictive biomarkers for CDDP therapy in NSCLC.
Collapse
Affiliation(s)
- Ahmed El Sayed Mohammed
- Translational Research Center, Saitama Medical University International Medical Center, Hidaka, Saitama, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
127
|
Xue ZH, Feng C, Liu WL, Tan SM. A role of kindlin-3 in integrin αMβ2 outside-in signaling and the Syk-Vav1-Rac1/Cdc42 signaling axis. PLoS One 2013; 8:e56911. [PMID: 23437269 PMCID: PMC3577682 DOI: 10.1371/journal.pone.0056911] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2012] [Accepted: 01/15/2013] [Indexed: 11/18/2022] Open
Abstract
Integrins mediate cell-cell and cell-extracellular matrix attachments. Integrins are signaling receptors because their cytoplasmic tails are docking sites for cytoskeletal and signaling proteins. Kindlins are a family of band 4.1-ezrin-radixin-moesin-containing intracellular proteins. Apart from regulating integrin ligand-binding affinity, recent evidence suggests that kindlins are involved in integrin outside-in signaling. Kindlin-3 is expressed in platelets, hematopoietic cells and endothelial cells. In humans, loss of kindlin-3 expression accounts for the rare autosomal disease leukocyte adhesion deficiency (LAD) type III that is characterized by bleeding disorders and defective recruitment of leukocytes into sites of infection. Studies have shown that the loss of kindlin-3 expression leads to poor ligand-binding properties of β1, β2 and β3 integrin subfamilies. The leukocyte-restricted β2 integrin subfamily comprises four members, namely αLβ2, αMβ2, αXβ2 and αDβ2. Integrin αMβ2 mediates leukocyte adhesion, phagocytosis, degranulation and it is involved in the maintenance of immune tolerance. Here we provide further evidence that kindlin-3 is required for integrin αMβ2-mediated cell adhesion and spreading using transfected K562 cells that expressed endogenous kindlin-3 but not β2 integrins. K562 stable cell line expressing si-RNA targeting kindlin-3, but not control-si-RNA, and transfected with constitutively activated integrin αMβ2N329S adhered and spread poorly on iC3b. We also show that kindlin-3 is required for the integrin αMβ2-Syk-Vav1 signaling axis that regulates Rac1 and Cdc42 activities. These findings reinforce a role for kindlin-3 in integrin outside-in signaling.
Collapse
Affiliation(s)
- Zhi-Hong Xue
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Chen Feng
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Wei-Ling Liu
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Suet-Mien Tan
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- * E-mail:
| |
Collapse
|
128
|
Yue J, Huhn S, Shen Z. Complex roles of filamin-A mediated cytoskeleton network in cancer progression. Cell Biosci 2013; 3:7. [PMID: 23388158 PMCID: PMC3573937 DOI: 10.1186/2045-3701-3-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 01/10/2013] [Indexed: 01/08/2023] Open
Abstract
Filamin-A (FLNA), also called actin-binding protein 280 (ABP-280), was originally identified as a non-muscle actin binding protein, which organizes filamentous actin into orthogonal networks and stress fibers. Filamin-A also anchors various transmembrane proteins to the actin cytoskeleton and provides a scaffold for a wide range of cytoplasmic and nuclear signaling proteins. Intriguingly, several studies have revealed that filamin-A associates with multiple non-cytoskeletal proteins of diverse function and is involved in several unrelated pathways. Mutations and aberrant expression of filamin-A have been reported in human genetic diseases and several types of cancer. In this review, we discuss the implications of filamin-A in cancer progression, including metastasis and DNA damage response.
Collapse
Affiliation(s)
- Jingyin Yue
- Department of Radiation Oncology, The Cancer Institute of New Jersey, Robert Wood Johnson Medical School, New Brunswick, NJ, 08903, USA.
| | | | | |
Collapse
|
129
|
Yuen HF, McCrudden CM, Huang YH, Tham JM, Zhang X, Zeng Q, Zhang SD, Hong W. TAZ expression as a prognostic indicator in colorectal cancer. PLoS One 2013; 8:e54211. [PMID: 23372686 PMCID: PMC3553150 DOI: 10.1371/journal.pone.0054211] [Citation(s) in RCA: 118] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Accepted: 12/10/2012] [Indexed: 12/15/2022] Open
Abstract
The Hippo pathway restricts the activity of transcriptional coactivators TAZ (WWTR1) and YAP. TAZ and YAP are reported to be overexpressed in various cancers, however, their prognostic significance in colorectal cancers remains unstudied. The expression levels of TAZ and YAP, and their downstream transcriptional targets, AXL and CTGF, were extracted from two independent colon cancer patient datasets available in the Gene Expression Omnibus database, totaling 522 patients. We found that mRNA expressions of both TAZ and YAP were positively correlated with those of AXL and CTGF (p<0.05). High level mRNA expression of TAZ, AXL or CTGF significantly correlated with shorter survival. Importantly, patients co-overexpressing all 3 genes had a significantly shorter survival time, and combinatorial expression of these 3 genes was an independent predictor for survival. The downstream target genes for TAZ-AXL-CTGF overexpression were identified by Java application MyStats. Interestingly, genes that are associated with colon cancer progression (ANTXR1, EFEMP2, SULF1, TAGLN, VCAN, ZEB1 and ZEB2) were upregulated in patients co-overexpressing TAZ-AXL-CTGF. This TAZ-AXL-CTGF gene expression signature (GES) was then applied to Connectivity Map to identify small molecules that could potentially be utilized to reverse this GES. Of the top 20 small molecules identified by connectivity map, amiloride (a potassium sparing diuretic,) and tretinoin (all-trans retinoic acid) have shown therapeutic promise in inhibition of colon cancer cell growth. Using MyStats, we found that low level expression of either ANO1 or SQLE were associated with a better prognosis in patients who co-overexpressed TAZ-AXL-CTGF, and that ANO1 was an independent predictor of survival together with TAZ-AXL-CTGF. Finally, we confirmed that TAZ regulates Axl, and plays an important role in clonogenicity and non-adherent growth in vitro and tumor formation in vivo. These data suggest that TAZ could be a therapeutic target for the treatment of colon cancer.
Collapse
Affiliation(s)
- Hiu-Fung Yuen
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (ASTAR), Singapore, Singapore
| | | | | | | | | | | | | | | |
Collapse
|
130
|
Sachs N, Sonnenberg A. Cell-matrix adhesion of podocytes in physiology and disease. Nat Rev Nephrol 2013; 9:200-10. [PMID: 23338211 DOI: 10.1038/nrneph.2012.291] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Cell-matrix adhesion is crucial for maintaining the mechanical integrity of epithelial tissues. Podocytes--a key component of the glomerular filtration barrier--are exposed to permanent transcapillary filtration pressure and must therefore adhere tightly to the underlying glomerular basement membrane (GBM). The major cell-matrix adhesion receptor in podocytes is the integrin α3β1, which connects laminin 521 in the GBM through various adaptor proteins to the intracellular actin cytoskeleton. Other cell-matrix adhesion receptors expressed by podocytes include the integrins α2β1 and αvβ3, α-dystroglycan, syndecan-4 and type XVII collagen. Mutations in genes encoding any of the components critical for podocyte adhesion cause glomerular disease. This Review highlights recent advances in our understanding of the cell biology and genetics of podocyte adhesion with special emphasis on glomerular disease.
Collapse
Affiliation(s)
- Norman Sachs
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | | |
Collapse
|
131
|
A feedback regulation between Kindlin-2 and GLI1 in prostate cancer cells. FEBS Lett 2013; 587:631-8. [PMID: 23337877 DOI: 10.1016/j.febslet.2012.12.028] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 12/05/2012] [Accepted: 12/21/2012] [Indexed: 01/15/2023]
Abstract
Kindlin-2 is engaged in tumor progression. However, the mechanism accounting for Kindlin-2 regulation in tumor cells remained largely unknown. Here, we report a regulatory loop between Kindlin-2 and GLI1, an effector of Hedgehog signaling pathway. We show that Kindlin-2 is transcriptionally downregulated via GLI1 occupancy on the Kindlin-2 promoter. Adversely, we found that Kindlin-2 promotes GLI1 expression through a mechanism involving GSK3β inactivation and is independent of Smoothened. Functionally, knockdown of Kindlin-2 cooperates with cyclopamine, a Smoothened antagonist, to decrease the viability of prostate cancer cells. Taken together, targeting the Kindlin-2-GLI1 feedback loop may facilitate the killing of prostate cancer cells.
Collapse
|
132
|
RADVAK PETER, REPIC MARKO, SVASTOVA ELISKA, TAKACOVA MARTINA, CSADEROVA LUCIA, STRNAD HYNEK, PASTOREK JAROMIR, PASTOREKOVA SILVIA, KOPACEK JURAJ. Suppression of carbonic anhydrase IX leads to aberrant focal adhesion and decreased invasion of tumor cells. Oncol Rep 2013; 29:1147-53. [DOI: 10.3892/or.2013.2226] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Accepted: 12/05/2012] [Indexed: 11/06/2022] Open
|
133
|
Yates LA, Lumb CN, Brahme NN, Zalyte R, Bird LE, De Colibus L, Owens RJ, Calderwood DA, Sansom MSP, Gilbert RJC. Structural and functional characterization of the kindlin-1 pleckstrin homology domain. J Biol Chem 2012; 287:43246-61. [PMID: 23132860 PMCID: PMC3527912 DOI: 10.1074/jbc.m112.422089] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 10/21/2012] [Indexed: 11/06/2022] Open
Abstract
Inside-out activation of integrins is mediated via the binding of talin and kindlin to integrin β-subunit cytoplasmic tails. The kindlin FERM domain is interrupted by a pleckstrin homology (PH) domain within its F2 subdomain. Here, we present data confirming the importance of the kindlin-1 PH domain for integrin activation and its x-ray crystal structure at a resolution of 2.1 Å revealing a C-terminal second α-helix integral to the domain but found only in the kindlin protein family. An isoform-specific salt bridge occludes the canonical phosphoinositide binding site, but molecular dynamics simulations display transient switching to an alternative open conformer. Molecular docking reveals that the opening of the pocket would enable potential ligands to bind within it. Although lipid overlay assays suggested the PH domain binds inositol monophosphates, surface plasmon resonance demonstrated weak affinities for inositol 3,4,5-triphosphate (Ins(3,4,5)P(3); K(D) ∼100 μM) and no monophosphate binding. Removing the salt bridge by site-directed mutagenesis increases the PH domain affinity for Ins(3,4,5)P(3) as measured by surface plasmon resonance and enables it to bind PtdIns(3,5)P(2) on a dot-blot. Structural comparison with other PH domains suggests that the phosphate binding pocket in the kindlin-1 PH domain is more occluded than in kindlins-2 and -3 due to its salt bridge. In addition, the apparent affinity for Ins(3,4,5)P(3) is affected by the presence of PO(4) ions in the buffer. We suggest the physiological ligand of the kindlin-1 PH domain is most likely not an inositol phosphate but another phosphorylated species.
Collapse
Affiliation(s)
- Luke A. Yates
- From the Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, United Kingdom
| | - Craig N. Lumb
- the Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Nina N. Brahme
- the Department of Cell Biology and
- the Department of Pharmacology Yale University School of Medicine, New Haven, Connecticut 06520-8066, and
| | - Ruta Zalyte
- From the Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, United Kingdom
| | - Louise E. Bird
- From the Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, United Kingdom
- the Oxford Protein Production Facility United Kingdom, Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0FA, United Kingdom
| | - Luigi De Colibus
- From the Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, United Kingdom
| | - Raymond J. Owens
- From the Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, United Kingdom
- the Oxford Protein Production Facility United Kingdom, Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0FA, United Kingdom
| | - David A. Calderwood
- the Department of Cell Biology and
- the Department of Pharmacology Yale University School of Medicine, New Haven, Connecticut 06520-8066, and
| | - Mark S. P. Sansom
- the Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Robert J. C. Gilbert
- From the Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, United Kingdom
| |
Collapse
|
134
|
Gkretsi V, Papanikolaou V, Dubos S, Papathanasiou I, Giotopoulou N, Valiakou V, Wu C, Malizos KN, Tsezou A. Migfilin's elimination from osteoarthritic chondrocytes further promotes the osteoarthritic phenotype via β-catenin upregulation. Biochem Biophys Res Commun 2012; 430:494-9. [PMID: 23237804 DOI: 10.1016/j.bbrc.2012.12.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Accepted: 12/04/2012] [Indexed: 01/18/2023]
Abstract
Osteoarthritis (OA) is a debilitating disease of the joints characterized by cartilage degradation but to date there is no available pharmacological treatment to inhibit disease progression neither is there any available biomarker to predict its development. In the present study, we examined the expression level and possible involvement of novel cell-ECM adhesion-related molecules such as Iintegrin Linked Kinase (ILK), PINCH, parvin, Mig-2 and Migfilin in OA pathogenesis using primary human articular chondrocytes from healthy individuals and OA patients. Our findings show that only ILK and Migfilin were upregulated in OA compared to the normal chondrocytes. Interestingly, Migfilin silencing in OA chondrocytes rather exacerbated than ameliorated the osteoarthritic phenotype, as it resulted in even higher levels of catabolic and hypertrophic markers while at the same time induced reduction in ECM molecules such as aggrecan. Furthermore, we also provide a link between Migfilin and β-catenin activation in OA chondrocytes, showing Migfilin to be inversely correlated with β-catenin. Thus, the present study emphasizes for the first time to our knowledge the role of Migfilin in OA and highlights the importance of cell-ECM adhesion proteins in OA pathogenesis.
Collapse
Affiliation(s)
- Vasiliki Gkretsi
- Center for Research and Technology-Thessaly (CE.RE.TE.TH), Department of Biomedical Research and Technology, Larissa 41222, Greece.
| | | | | | | | | | | | | | | | | |
Collapse
|
135
|
Rajshankar D, Downey GP, McCulloch CA. IL-1β enhances cell adhesion to degraded fibronectin. FASEB J 2012; 26:4429-44. [PMID: 22829527 PMCID: PMC3475244 DOI: 10.1096/fj.12-207381] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 07/10/2012] [Indexed: 01/01/2023]
Abstract
IL-1β is a prominent proinflammatory cytokine that mediates degradation of extracellular matrix proteins through increased expression of matrix metalloproteinases, which involves a signaling pathway in adherent cells that is restricted by focal adhesions. Currently, the mechanism by which IL-1β affects cell adhesion to matrix proteins is not defined, and it is not known whether degraded matrix proteins affect IL-1β signaling. We examined adhesion-related IL-1β signaling in fibroblasts attaching to native or MMP3-degraded fibronectin. IL-1β increased cell attachment, resistance to shear force and the numbers of focal adhesions containing activated β(1) integrins. IL-1β-enhanced attachment required FAK, kindlins 1/2, and talin. MMP3-degraded fibronectin-inhibited IL-1β-enhanced cell adhesion and promoted spontaneous ERK activation that was independent of IL-1β treatment. We conclude that IL-1β enhances the adhesion of anchorage-dependent cells to MMP3-degraded fibronectin, which, in turn, is associated with deregulated cellular responses to IL-1β. These data point to a novel role of IL-1β as a proadhesive signaling molecule in inflammation that employs kindlins and talin to regulate adhesion.
Collapse
Affiliation(s)
| | - Gregory P. Downey
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, National Jewish Health, Denver, Colorado, USA; and
- Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, and
- Integrated Department of Immunology, University of Colorado, Aurora, Colorado, USA
| | | |
Collapse
|
136
|
Davidson B, Holth A, Nguyen MTP, Tropé CG, Wu C. Migfilin, α-parvin and β-parvin are differentially expressed in ovarian serous carcinoma effusions, primary tumors and solid metastases. Gynecol Oncol 2012; 128:364-70. [PMID: 23099104 DOI: 10.1016/j.ygyno.2012.10.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Revised: 10/10/2012] [Accepted: 10/14/2012] [Indexed: 12/17/2022]
Abstract
OBJECTIVE The objective of this study is to analyze the expression and clinical role of integrin-linked kinase (ILK), α-parvin, β-parvin and migfilin in advanced-stage serous ovarian carcinoma. METHODS Expression of these 4 proteins was investigated in 205 effusions and in 94 patient-matched solid lesions (33 primary tumors and 61 solid metastases) using immunohistochemistry. Protein expression was analyzed for association with clinicopathologic parameters and survival. RESULTS ILK, α-parvin, β-parvin and migfilin were expressed in tumor cells in 53%, 2%, 28% and 53% of effusions and 57%, 20%, 83% and 25% of solid lesions, respectively. Statistical analysis showed significantly higher α-parvin and β-parvin expression in primary carcinomas (p=0.02 and p=0.001, respectively) and solid metastases (p=0.001 and p<0.001, respectively), compared to effusions, with opposite findings for migfilin (p=0.006 and p=0.008 for primary carcinomas and solid metastases, respectively). ILK expression was comparable at all anatomic sites. β-Parvin expression in effusions was associated with better response to chemotherapy at diagnosis (p=0.014), with no other significant association with clinicopathologic parameters or survival. Expression in primary tumors and solid metastases was similarly unrelated to clinicopathologic parameters or survival. CONCLUSIONS This study provides further evidence to our previous observations that the adhesion profile of ovarian serous carcinoma cells in effusions differs from their counterparts in primary carcinomas and solid metastases. β-Parvin may be a novel marker of chemoresponse in metastatic ovarian carcinoma.
Collapse
Affiliation(s)
- Ben Davidson
- Division of Pathology, Oslo University Hospital, Norwegian Radium Hospital, N-0424 Oslo, Norway.
| | | | | | | | | |
Collapse
|
137
|
Schulz S, Tomakidi P, Mauth C, Kohal R, Steinberg T. Interactive Fibroblast-Keratinocyte Co-cultures: AnIn Vivo-Like Test Platform for Dental Implant-Based Soft Tissue Integration. Tissue Eng Part C Methods 2012; 18:785-96. [DOI: 10.1089/ten.tec.2012.0027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Simon Schulz
- Department of Oral Biotechnology, Dental School, University Hospital Freiburg, Freiburg, Germany
| | - Pascal Tomakidi
- Department of Oral Biotechnology, Dental School, University Hospital Freiburg, Freiburg, Germany
| | | | - Ralf Kohal
- Department of Prosthodontics, Dental School, University Hospital Freiburg, Freiburg, Germany
| | - Thorsten Steinberg
- Department of Oral Biotechnology, Dental School, University Hospital Freiburg, Freiburg, Germany
| |
Collapse
|
138
|
Assembly and disassembly of cell matrix adhesions. Curr Opin Cell Biol 2012; 24:569-81. [DOI: 10.1016/j.ceb.2012.06.010] [Citation(s) in RCA: 160] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 06/12/2012] [Accepted: 06/28/2012] [Indexed: 11/22/2022]
|
139
|
Fan J, Ou YW, Wu CY, Yu CJ, Song YM, Zhan QM. Migfilin sensitizes cisplatin-induced apoptosis in human glioma cells in vitro. Acta Pharmacol Sin 2012; 33:1301-10. [PMID: 22983390 DOI: 10.1038/aps.2012.123] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
AIM Filamin binding LIM protein 1, also known as migfilin, is a skeleton organization protein that binds to mitogen-inducible gene 2 at cell-extracellular matrix adhesions. The aim of this study was to investigate the role of migfilin in cisplatin-induced apoptosis in human glioma cells, to determine the functional domains of migfilin, and to elucidate the molecular mechanisms underlying the regulation of cisplatin-related chemosensitivity. METHODS The human glioma cell lines Hs683, H4, and U-87 MG were transfected with pEGFP-C2-migfilin to elevate the expression level of migfilin. RNA interference was used to reduce the expression of migfilin. To determine the functional domains of migfilin, U-87 MG cells were transfected with plasmids of migfilin deletion mutants. After treatment with cisplatin (40 μmol/L) for 24 h, the cell viability was assessed using the MTS assay, and the cell apoptotic was examined using the DAPI staining assay and TUNEL analysis. Expression levels of apoptosis-related proteins were detected by Western blot analysis. RESULTS Overexpression of migfilin significantly enhanced cisplatin-induced apoptosis in Hs683, H4, and U-87 MG cells, whereas downregulation of migfilin expression inhibited the chemosensitivity of these cell lines. The N-terminal region of migfilin alone was able to enhance the cisplatin-induced apoptosis. However, despite the existence of the N-terminal region, mutants of migfilin with any one of three LIM domains deleted led to a function loss. Furthermore, apoptotic proteins (PARP and caspase-3) and the anti-apoptotic protein Bcl-xL were modulated by the expression level of migfilin in combination with cisplatin. CONCLUSION The LIM1-3 domains of migfilin play a key role in sensitizing glioma cells to cisplatin-induced apoptosis through regulation of apoptosis-related proteins.
Collapse
|
140
|
Kindlin-1 enhances axon growth on inhibitory chondroitin sulfate proteoglycans and promotes sensory axon regeneration. J Neurosci 2012; 32:7325-35. [PMID: 22623678 DOI: 10.1523/jneurosci.5472-11.2012] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Growing and regenerating axons need to interact with the molecules in the extracellular matrix as they traverse through their environment. An important group of receptors that serve this function is the integrin superfamily of cell surface receptors, which are evolutionarily conserved αβ heterodimeric transmembrane proteins. The function of integrins is controlled by regulating the affinity for ligands (also called "integrin activation"). Previous results have shown that CNS inhibitory molecules inactivate axonal integrins, while enhancing integrin activation can promote axon growth from neurons cultured on inhibitory substrates. We tested two related molecules, kindlin-1 and kindlin-2 (Fermitin family members 1 and 2), that can activate β1, β2, and β3 integrins, for their effects on integrin signaling and integrin-mediated axon growth in rat sensory neurons. We determined that kindlin-2, but not kindlin-1, is endogenously expressed in the nervous system. Knocking down kindlin-2 levels in cultured sensory neurons impaired their ability to extend axons, but this was partially rescued by kindlin-1 expression. Overexpression of kindlin-1, but not kindlin-2, in cultured neurons increased axon growth on an inhibitory aggrecan substrate. This was found to be associated with enhanced integrin activation and signaling within the axons. Additionally, in an in vivo rat dorsal root injury model, transduction of dorsal root ganglion neurons to express kindlin-1 promoted axon regeneration across the dorsal root entry zone and into the spinal cord. These animals demonstrated improved recovery of thermal sensation following injury. Our results therefore suggest that kindlin-1 is a potential tool for improving axon regeneration after nervous system lesions.
Collapse
|
141
|
Ou Y, Ma L, Dong L, Ma L, Zhao Z, Ma L, Zhou W, Fan J, Wu C, Yu C, Zhan Q, Song Y. Migfilin protein promotes migration and invasion in human glioma through epidermal growth factor receptor-mediated phospholipase C-γ and STAT3 protein signaling pathways. J Biol Chem 2012; 287:32394-405. [PMID: 22843679 PMCID: PMC3463316 DOI: 10.1074/jbc.m112.393900] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Migfilin is critical for cell shape and motile regulation. However, its pathological role in glioma is unknown. Using an immunohistochemical staining assay, we demonstrate that there is a significant correlation between expression of Migfilin and pathological tumor grade in 217 clinical glioma samples. High Migfilin expression is associated with poor prognosis for patients with glioma. Investigation of the molecular mechanism shows that Migfilin promotes migration and invasion in glioma cells. Moreover, Migfilin positively modulates the expression and activity of epidermal growth factor receptor, and Migfilin-mediated migration and invasion depend on epidermal growth factor receptor-induced PLC-γ and STAT3-signaling pathways. Our results may provide significant clinical application, including use of Migfilin as a molecular marker in glioma for early diagnosis and as an indicator of prognosis.
Collapse
Affiliation(s)
- Yunwei Ou
- Department of Neurosurgery, Beijing Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
142
|
The leucocyte β2 (CD18) integrins: the structure, functional regulation and signalling properties. Biosci Rep 2012; 32:241-69. [PMID: 22458844 DOI: 10.1042/bsr20110101] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Leucocytes are highly motile cells. Their ability to migrate into tissues and organs is dependent on cell adhesion molecules. The integrins are a family of heterodimeric transmembrane cell adhesion molecules that are also signalling receptors. They are involved in many biological processes, including the development of metazoans, immunity, haemostasis, wound healing and cell survival, proliferation and differentiation. The leucocyte-restricted β2 integrins comprise four members, namely αLβ2, αMβ2, αXβ2 and αDβ2, which are required for a functional immune system. In this paper, the structure, functional regulation and signalling properties of these integrins are reviewed.
Collapse
|
143
|
Bledzka K, Liu J, Xu Z, Perera HD, Yadav SP, Bialkowska K, Qin J, Ma YQ, Plow EF. Spatial coordination of kindlin-2 with talin head domain in interaction with integrin β cytoplasmic tails. J Biol Chem 2012; 287:24585-94. [PMID: 22648415 PMCID: PMC3397883 DOI: 10.1074/jbc.m111.336743] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Revised: 05/29/2012] [Indexed: 12/20/2022] Open
Abstract
Both talin head domain and kindlin-2 interact with integrin β cytoplasmic tails, and they function in concert to induce integrin activation. Binding of talin head domain to β cytoplasmic tails has been characterized extensively, but information on the interaction of kindin-2 with this integrin segment is limited. In this study, we systematically examine the interactions of kindlin-2 with integrin β tails. Kindlin-2 interacted well with β(1) and β(3) tails but poorly with the β(2) cytoplasmic tail. This binding selectivity was determined by the non-conserved residues, primarily the three amino acids at the extreme C terminus of the β(3) tail, and the sequence in β(2) was non-permissive. The region at the C termini of integrin β(1) and β(3) tails recognized by kindlin-2 was a binding core of 12 amino acids. Kindlin-2 and talin head do not interact with one another but can bind simultaneously to the integrin β(3) tail without enhancing or inhibiting the interaction of the other binding partner. Kindlin-2 itself failed to directly unclasp integrin α/β tail complex, indicating that kindlin-2 must cooperate with talin to support the integrin activation mechanism.
Collapse
Affiliation(s)
- Kamila Bledzka
- From the Department of Molecular Cardiology, Joseph J. Jacobs Center for Thrombosis and Vascular Biology/NB-50 and
| | - Jianmin Liu
- From the Department of Molecular Cardiology, Joseph J. Jacobs Center for Thrombosis and Vascular Biology/NB-50 and
| | - Zhen Xu
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, Wisconsin 53226
| | - H. Dhanuja Perera
- From the Department of Molecular Cardiology, Joseph J. Jacobs Center for Thrombosis and Vascular Biology/NB-50 and
| | - Satya P. Yadav
- Research Core Services, Department of Molecular Biotechnology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195 and
| | - Katarzyna Bialkowska
- From the Department of Molecular Cardiology, Joseph J. Jacobs Center for Thrombosis and Vascular Biology/NB-50 and
| | - Jun Qin
- From the Department of Molecular Cardiology, Joseph J. Jacobs Center for Thrombosis and Vascular Biology/NB-50 and
| | - Yan-Qing Ma
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, Wisconsin 53226
| | - Edward F. Plow
- From the Department of Molecular Cardiology, Joseph J. Jacobs Center for Thrombosis and Vascular Biology/NB-50 and
| |
Collapse
|
144
|
Roca-Cusachs P, Iskratsch T, Sheetz MP. Finding the weakest link: exploring integrin-mediated mechanical molecular pathways. J Cell Sci 2012; 125:3025-38. [PMID: 22797926 DOI: 10.1242/jcs.095794] [Citation(s) in RCA: 176] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
From the extracellular matrix to the cytoskeleton, a network of molecular links connects cells to their environment. Molecules in this network transmit and detect mechanical forces, which subsequently determine cell behavior and fate. Here, we reconstruct the mechanical pathway followed by these forces. From matrix proteins to actin through integrins and adaptor proteins, we review how forces affect the lifetime of bonds and stretch or alter the conformation of proteins, and how these mechanical changes are converted into biochemical signals in mechanotransduction events. We evaluate which of the proteins in the network can participate in mechanotransduction and which are simply responsible for transmitting forces in a dynamic network. Besides their individual properties, we also analyze how the mechanical responses of a protein are determined by their serial connections from the matrix to actin, their parallel connections in integrin clusters and by the rate at which force is applied to them. All these define mechanical molecular pathways in cells, which are emerging as key regulators of cell function alongside better studied biochemical pathways.
Collapse
Affiliation(s)
- Pere Roca-Cusachs
- University of Barcelona and Institute for Bioengineering of Catalonia, Barcelona, Spain.
| | | | | |
Collapse
|
145
|
Abstract
Lymphocyte function-associated antigen-1 (LFA-1) is a heterodimeric integrin consisting of αL (gene name, Itgal) and β2 (gene name, Itgb2) subunits expressed in all leukocytes. LFA-1 is essential for neutrophil recruitment to inflamed tissue. Activation of LFA-1 by chemokines allows neutrophils and other leukocytes to undergo arrest, resulting in firm adhesion on endothelia expressing intercellular adhesion molecules (ICAMs). In mice, CXCR2 is the primary chemokine receptor involved in triggering neutrophil arrest, and it does so through “inside-out” activation of LFA-1. CXCR2 signaling induces changes in LFA-1 conformation that are coupled to affinity upregulation of the ligand-binding headpiece (extended with open I domain). Unlike naïve lymphocytes, engagement of P-selectin glycoprotein ligand-1 (PSGL-1) on neutrophils stimulates a slow rolling behavior that is mediated by LFA-1 in a distinct activation state (extended with closed I domain). How inside-out signaling cascades regulate the structure and function of LFA-1 is being studied using flow chambers, intravital microscopy, and flow cytometry for ligand and reporter antibody binding. Here, we review how LFA-1 activation is regulated by cellular signaling and ligand binding. Two FERM domain-containing proteins, talin-1 and Kindlin-3, are critical integrin co-activators and have distinct roles in the induction of LFA-1 conformational rearrangements. This review integrates these new results into existing models of LFA-1 activation.
Collapse
Affiliation(s)
- Craig T Lefort
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA, USA
| | | |
Collapse
|
146
|
Xiao G, Cheng H, Cao H, Chen K, Tu Y, Yu S, Jiao H, Yang S, Im HJ, Chen D, Chen J, Wu C. Critical role of filamin-binding LIM protein 1 (FBLP-1)/migfilin in regulation of bone remodeling. J Biol Chem 2012; 287:21450-60. [PMID: 22556421 DOI: 10.1074/jbc.m111.331249] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Bone remodeling is a complex process that must be precisely controlled to maintain a healthy life. We show here that filamin-binding LIM protein 1 (FBLP-1, also known as migfilin), a kindlin- and filamin-binding focal adhesion protein, is essential for proper control of bone remodeling. Genetic inactivation of FBLIM1 (the gene encoding FBLP-1) in mice resulted in a severe osteopenic phenotype. Primary FBLP-1 null bone marrow stromal cells (BMSCs) exhibited significantly reduced extracellular matrix adhesion and migration compared with wild type BMSCs. Loss of FBLP-1 significantly impaired the growth and survival of BMSCs in vitro and decreased the number of osteoblast (OB) progenitors in bone marrow and OB differentiation in vivo. Furthermore, the loss of FBLP-1 caused a dramatic increase of osteoclast (OCL) differentiation in vivo. The level of receptor activator of nuclear factor κB ligand (RANKL), a key regulator of OCL differentiation, was markedly increased in FBLP-1 null BMSCs. The capacity of FBLP-1 null bone marrow monocytes (BMMs) to differentiate into multinucleated OCLs in response to exogenously supplied RANKL, however, was not different from that of WT BMMs. Finally, we show that a loss of FBLP-1 promotes activating phosphorylation of ERK1/2. Inhibition of ERK1/2 activation substantially suppressed the increase of RANKL induced by the loss of FBLP-1. Our results identify FBLP-1 as a key regulator of bone homeostasis and suggest that FBLP-1 functions in this process through modulating both the intrinsic properties of OB/BMSCs (i.e., BMSC-extracellular matrix adhesion and migration, cell growth, survival, and differentiation) and the communication between OB/BMSCs and BMMs (i.e., RANKL expression) that controls osteoclastogenesis.
Collapse
Affiliation(s)
- Guozhi Xiao
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15240, USA.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
147
|
Romero OA, Setien F, John S, Gimenez-Xavier P, Gómez-López G, Pisano D, Condom E, Villanueva A, Hager GL, Sanchez-Cespedes M. The tumour suppressor and chromatin-remodelling factor BRG1 antagonizes Myc activity and promotes cell differentiation in human cancer. EMBO Mol Med 2012; 4:603-16. [PMID: 22407764 PMCID: PMC3407948 DOI: 10.1002/emmm.201200236] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Revised: 02/27/2012] [Accepted: 02/29/2012] [Indexed: 12/30/2022] Open
Abstract
BRG1, a member of the SWI/SNF complex, is mutated in cancer, but it is unclear how it promotes tumourigenesis. We report that re-expression of BRG1 in lung cancer cells up-regulates lung-specific transcripts, restoring the gene expression signature of normal lung. Using cell lines from several cancer types we found that those lacking BRG1 do not respond to retinoic acid (RA) or glucocorticoids (GC), while restoration of BRG1 restores sensitivity. Conversely, in SH-SY5Y cells, a paradigm of RA-dependent differentiation, abrogation of BRG1 prevented the response to RA. Further, our data suggest an antagonistic functional connection between BRG1 and MYC, whereby, refractoriness to RA and GC by BRG1 inactivation involves deregulation of MYC activity. Mechanistically, some of these effects are mediated by BRG1 binding to MYC and MYC-target promoters. The BRG1-MYC antagonism was also evident in primary tumours. Finally, BRG1 restoration significantly dampened invasion and progression and decreased MYC in lung cancer cells orthotopically implanted in nude mice. Thus, BRG1 inactivation enables cancer cells to sustain undifferentiated gene expression programs and prevent its response to environmental stimuli.
Collapse
Affiliation(s)
- Octavio A Romero
- Genes and Cancer Group, Cancer Epigenetics and Biology Program-PEBC, Bellvitge Biomedical Research Institute-IDIBELL, Hospitalet de Llobregat, Barcelona, Spain
| | | | | | | | | | | | | | | | | | | |
Collapse
|
148
|
Kahner BN, Kato H, Banno A, Ginsberg MH, Shattil SJ, Ye F. Kindlins, integrin activation and the regulation of talin recruitment to αIIbβ3. PLoS One 2012; 7:e34056. [PMID: 22457811 PMCID: PMC3311585 DOI: 10.1371/journal.pone.0034056] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Accepted: 02/21/2012] [Indexed: 11/18/2022] Open
Abstract
Talins and kindlins bind to the integrin β3 cytoplasmic tail and both are required for effective activation of integrin αIIbβ3 and resulting high-affinity ligand binding in platelets. However, binding of the talin head domain alone to β3 is sufficient to activate purified integrin αIIbβ3 in vitro. Since talin is localized to the cytoplasm of unstimulated platelets, its re-localization to the plasma membrane and to the integrin is required for activation. Here we explored the mechanism whereby kindlins function as integrin co-activators. To test whether kindlins regulate talin recruitment to plasma membranes and to αIIbβ3, full-length talin and kindlin recruitment to β3 was studied using a reconstructed CHO cell model system that recapitulates agonist-induced αIIbβ3 activation. Over-expression of kindlin-2, the endogenous kindlin isoform in CHO cells, promoted PAR1-mediated and talin-dependent ligand binding. In contrast, shRNA knockdown of kindlin-2 inhibited ligand binding. However, depletion of kindlin-2 by shRNA did not affect talin recruitment to the plasma membrane, as assessed by sub-cellular fractionation, and neither over-expression of kindlins nor depletion of kindlin-2 affected talin interaction with αIIbβ3 in living cells, as monitored by bimolecular fluorescence complementation. Furthermore, talin failed to promote kindlin-2 association with αIIbβ3 in CHO cells. In addition, purified talin and kindlin-3, the kindlin isoform expressed in platelets, failed to promote each other's binding to the β3 cytoplasmic tail in vitro. Thus, kindlins do not promote initial talin recruitment to αIIbβ3, suggesting that they co-activate integrin through a mechanism independent of recruitment.
Collapse
Affiliation(s)
- Bryan N Kahner
- Department of Medicine, University of California San Diego, La Jolla, California, United States of America
| | | | | | | | | | | |
Collapse
|
149
|
Perera HD, Ma YQ, Yang J, Hirbawi J, Plow EF, Qin J. Membrane binding of the N-terminal ubiquitin-like domain of kindlin-2 is crucial for its regulation of integrin activation. Structure 2012; 19:1664-71. [PMID: 22078565 DOI: 10.1016/j.str.2011.08.012] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 08/03/2011] [Accepted: 08/19/2011] [Indexed: 11/25/2022]
Abstract
Kindlin-2 belongs to an emerging class of regulators for heterodimeric (α/β) integrin adhesion receptors. By binding to integrin β cytoplasmic tail via its C-terminal FERM-like domain, kindlin-2 promotes integrin activation. Intriguingly, this activation process depends on the N terminus of kindlin-2 (K2-N) that precedes the FERM domain. The molecular function of K2-N is unclear. We present the solution structure of K2-N, which displays a ubiquitin fold similar to that observed in kindlin-1. Using chemical shift mapping and mutagenesis, we found that K2-N contains a conserved positively charged surface that binds to membrane enriched with negatively charged phosphatidylinositol-(4,5)-bisphosphate. We show that while wild-type kindlin-2 is capable of promoting integrin activation, such ability is significantly reduced for its membrane-binding defective mutant. These data suggest a membrane-binding function of the ubiquitin-like domain of kindlin-2, which is likely common for all kindlins to promote their localization to the plasma membrane and control integrin activation.
Collapse
Affiliation(s)
- H Dhanuja Perera
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA
| | | | | | | | | | | |
Collapse
|
150
|
Feng C, Li YF, Yau YH, Lee HS, Tang XY, Xue ZH, Zhou YC, Lim WM, Cornvik TC, Ruedl C, Shochat SG, Tan SM. Kindlin-3 mediates integrin αLβ2 outside-in signaling, and it interacts with scaffold protein receptor for activated-C kinase 1 (RACK1). J Biol Chem 2012; 287:10714-26. [PMID: 22334666 DOI: 10.1074/jbc.m111.299594] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Integrins are heterodimeric type I membrane cell adhesion molecules that are involved in many biological processes. Integrins are bidirectional signal transducers because their cytoplasmic tails are docking sites for cytoskeletal and signaling molecules. Kindlins are cytoplasmic molecules that mediate inside-out signaling and activation of the integrins. The three kindlin paralogs in humans are kindlin-1, -2, and -3. Each of these contains a 4.1-ezrin-radixin-moesin (FERM) domain and a pleckstrin homology domain. Kindlin-3 is expressed in platelets, hematopoietic cells, and endothelial cells. Here we show that kindlin-3 is involved in integrin αLβ2 outside-in signaling. It also promotes micro-clustering of integrin αLβ2. We provide evidence that kindlin-3 interacts with the receptor for activated-C kinase 1 (RACK1), a scaffold protein that folds into a seven-blade propeller. This interaction involves the pleckstrin homology domain of kindlin-3 and blades 5-7 of RACK1. Using the SKW3 human T lymphoma cells, we show that integrin αLβ2 engagement by its ligand ICAM-1 promotes the association of kindlin-3 with RACK1. We also show that kindlin-3 co-localizes with RACK1 in polarized SKW3 cells and human T lymphoblasts. Our findings suggest that kindlin-3 plays an important role in integrin αLβ2 outside-in signaling.
Collapse
Affiliation(s)
- Chen Feng
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|