1
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Wade EM, Goodin EA, Morgan T, Pereira S, Woolley AG, Jenkins ZA, Daniel PB, Robertson SP. The hinge-1 domain of Flna is not necessary for diverse physiological functions in mice. Eur J Clin Invest 2024:e14308. [PMID: 39215762 DOI: 10.1111/eci.14308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2024] [Accepted: 08/19/2024] [Indexed: 09/04/2024]
Abstract
INTRODUCTION The filamins are cytoskeletal binding proteins that dynamically crosslink actin into orthogonal networks or bundle it into stress fibres. The domain structure of filamin proteins is very well characterised, with an N-terminal actin-binding region, followed by 24 immunoglobulin-like repeat units. The repeat domains are separated into distinct segments by two regions of low-complexity known as hinge-1 and hinge-2. The role of hinge-1 especially has been proposed to be essential for protein function as it provides flexibility to the otherwise rigid protein, and is a target for cleavage by calpain. Hinge-1 protects cells from otherwise destructive forces, and the products of calpain cleavage are involved in critical cellular signalling processes, such as survival during hypoxia. Pathogenic variants in FLNA encoding Filamin A, including those that remove the hinge-1 domain, cause a wide range of survivable developmental disorders. In contrast, complete loss of function of this gene is embryonic lethal in human and mouse. METHODS AND RESULTS In this study, we show that removing filamin A hinge-1 from mouse (FlnaΔH1), while preserving its expression level leads to no obvious developmental phenotype. Detailed characterisation of the skeletons of FlnaΔH1 mice showed no skeletal phenotype reminiscent of that found in the FLNA-causing skeletal dysplasia. Furthermore, nuclear functions of FLNA are maintained with loss of Filamin A hinge-1. CONCLUSION We conclude that hinge-1 is dispensable for filamin A protein function during development over the murine lifespan.
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Affiliation(s)
- Emma M Wade
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Elizabeth A Goodin
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Tim Morgan
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Stephana Pereira
- Department of Pathology, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Adele G Woolley
- Department of Pathology, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
- Maurice Wilkins Centre for Biodiscovery, University of Otago, Dunedin, New Zealand
| | - Zandra A Jenkins
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Philip B Daniel
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Stephen P Robertson
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
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2
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Wade EM, Morgan T, Gimenez G, Jenkins ZA, Titheradge H, O'Donnell M, Skidmore D, Suri M, Robertson SP. Pathogenic FLNA variants affecting the hinge region of filamin A are associated with male survival. Am J Med Genet A 2024:e63779. [PMID: 38853608 DOI: 10.1002/ajmg.a.63779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 05/07/2024] [Accepted: 05/18/2024] [Indexed: 06/11/2024]
Abstract
Pathogenic variants in FLNA cause a diversity of X-linked developmental disorders associated with either preserved or diminished levels of filamin A protein and are conceptualized dichotomously as relating to underlying gain- or loss-of-function pathogenic mechanisms. Hemizygosity for germline deletions or truncating variants in FLNA is generally considered to result in embryonic lethality. Structurally, filamin A is composed of an N-terminal actin-binding region, followed by 24 immunoglobulin-like repeat units. The repeat domains are separated into distinct segments by two regions of low-complexity known as hinge-1 and hinge-2. Hinge-1 is proposed to confer flexibility to the otherwise rigid protein and is a target for cleavage by calpain with the resultant filamin fragments mediating crucial cellular signaling processes. Here, three families with pathogenic variants in FLNA that impair the function of hinge-1 in males are described, leading to distinct clinical phenotypes. One large in-frame deletion that includes the hinge leads to frontometaphyseal dysplasia in affected males and females, while two germline truncating variants located within the exon encoding hinge 1 result in phenotypes in males that are explained by exon skipping and under-expression of a transcript that deletes hinge-1 from the resultant protein. These three variants affecting hinge-1 indicate that this domain does not mediate cellular functions that, when deficientresult in embryonic lethality in males and that germline truncating variants in this region of FLNA can result in viable phenotypes in males.
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Affiliation(s)
- Emma M Wade
- Department of Women's and Children's Health, Dunedin School of Medicine, Otago University, Dunedin, New Zealand
| | - Tim Morgan
- Department of Women's and Children's Health, Dunedin School of Medicine, Otago University, Dunedin, New Zealand
| | - Gregory Gimenez
- Department of Pathology, Dunedin School of Medicine, Otago University, Dunedin, New Zealand
| | - Zandra A Jenkins
- Department of Women's and Children's Health, Dunedin School of Medicine, Otago University, Dunedin, New Zealand
| | - Hannah Titheradge
- Birmingham Women's and Children's NHS Foundation Trust, Birmingham, UK
| | - Marie O'Donnell
- Birmingham Women's and Children's NHS Foundation Trust, Birmingham, UK
| | - David Skidmore
- IWK Hospital, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Mohnish Suri
- Clinical Genetics Service, City Hospital, Nottingham, UK
| | - Stephen P Robertson
- Department of Women's and Children's Health, Dunedin School of Medicine, Otago University, Dunedin, New Zealand
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3
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Giovannelli P, Di Donato M, Licitra F, Sabbatino E, Tutino V, Castoria G, Migliaccio A. Filamin A in triple negative breast cancer. Steroids 2024; 205:109380. [PMID: 38311094 DOI: 10.1016/j.steroids.2024.109380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/06/2024]
Abstract
Triple-negative breast cancer is a rare but highly heterogeneous breast cancer subtype with a limited choice of specific treatments. Chemotherapy remains the only efficient treatment, but its side effects and the development of resistance consolidate the urgent need to discover new targets. In TNBC, filamin A expression correlates to grade and TNM stage. Accordingly, this protein could constitute a new target for this BC subtype. Even if most of the data indicates its direct involvement in cancer progression, some contrasting results underline the need to deepen the studies. To elucidate a possible function of this protein as a TNBC marker, we summarized the main characteristic of filamin A and its involvement in physiological and pathological processes such as cancer. Lastly, we scrutinized its actions in triple-negative breast cancer and highlighted the need to increase the number of studies useful to better clarify the role of this versatile protein as a marker and target in TNBC, alone or in "collaboration" with other proteins with a relevant role in this BC subgroup.
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Affiliation(s)
- Pia Giovannelli
- Department of Precision Medicine, University of Campania "L.Vanvitelli", Via L. De Crecchio, 7-80138 Naples, Italy.
| | - Marzia Di Donato
- Department of Precision Medicine, University of Campania "L.Vanvitelli", Via L. De Crecchio, 7-80138 Naples, Italy
| | - Fabrizio Licitra
- Department of Precision Medicine, University of Campania "L.Vanvitelli", Via L. De Crecchio, 7-80138 Naples, Italy
| | - Emilia Sabbatino
- Department of Precision Medicine, University of Campania "L.Vanvitelli", Via L. De Crecchio, 7-80138 Naples, Italy
| | - Viviana Tutino
- Department of Precision Medicine, University of Campania "L.Vanvitelli", Via L. De Crecchio, 7-80138 Naples, Italy
| | - Gabriella Castoria
- Department of Precision Medicine, University of Campania "L.Vanvitelli", Via L. De Crecchio, 7-80138 Naples, Italy
| | - Antimo Migliaccio
- Department of Precision Medicine, University of Campania "L.Vanvitelli", Via L. De Crecchio, 7-80138 Naples, Italy
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4
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Nguyen MT, Dash R, Jeong K, Lee W. Role of Actin-Binding Proteins in Skeletal Myogenesis. Cells 2023; 12:2523. [PMID: 37947600 PMCID: PMC10650911 DOI: 10.3390/cells12212523] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 10/22/2023] [Accepted: 10/23/2023] [Indexed: 11/12/2023] Open
Abstract
Maintenance of skeletal muscle quantity and quality is essential to ensure various vital functions of the body. Muscle homeostasis is regulated by multiple cytoskeletal proteins and myogenic transcriptional programs responding to endogenous and exogenous signals influencing cell structure and function. Since actin is an essential component in cytoskeleton dynamics, actin-binding proteins (ABPs) have been recognized as crucial players in skeletal muscle health and diseases. Hence, dysregulation of ABPs leads to muscle atrophy characterized by loss of mass, strength, quality, and capacity for regeneration. This comprehensive review summarizes the recent studies that have unveiled the role of ABPs in actin cytoskeletal dynamics, with a particular focus on skeletal myogenesis and diseases. This provides insight into the molecular mechanisms that regulate skeletal myogenesis via ABPs as well as research avenues to identify potential therapeutic targets. Moreover, this review explores the implications of non-coding RNAs (ncRNAs) targeting ABPs in skeletal myogenesis and disorders based on recent achievements in ncRNA research. The studies presented here will enhance our understanding of the functional significance of ABPs and mechanotransduction-derived myogenic regulatory mechanisms. Furthermore, revealing how ncRNAs regulate ABPs will allow diverse therapeutic approaches for skeletal muscle disorders to be developed.
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Affiliation(s)
- Mai Thi Nguyen
- Department of Biochemistry, Dongguk University College of Medicine, 123 Dongdae-ro, Gyeongju 38066, Republic of Korea; (M.T.N.); (K.J.)
| | - Raju Dash
- Department of Anatomy, Dongguk University College of Medicine, 123 Dongdae-ro, Gyeongju 38066, Republic of Korea;
- Department of New Biology, Daegu Gyeongbuk Institute of Science & Technology (DGIST), Daegu 42988, Republic of Korea
| | - Kyuho Jeong
- Department of Biochemistry, Dongguk University College of Medicine, 123 Dongdae-ro, Gyeongju 38066, Republic of Korea; (M.T.N.); (K.J.)
| | - Wan Lee
- Department of Biochemistry, Dongguk University College of Medicine, 123 Dongdae-ro, Gyeongju 38066, Republic of Korea; (M.T.N.); (K.J.)
- Channelopathy Research Center, Dongguk University College of Medicine, 32 Dongguk-ro, Ilsan Dong-gu, Goyang 10326, Republic of Korea
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Bachmann M, Su B, Rahikainen R, Hytönen VP, Wu J, Wehrle-Haller B. ConFERMing the role of talin in integrin activation and mechanosignaling. J Cell Sci 2023; 136:jcs260576. [PMID: 37078342 PMCID: PMC10198623 DOI: 10.1242/jcs.260576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/21/2023] Open
Abstract
Talin (herein referring to the talin-1 form), is a cytoskeletal adapter protein that binds integrin receptors and F-actin, and is a key factor in the formation and regulation of integrin-dependent cell-matrix adhesions. Talin forms the mechanical link between the cytoplasmic domain of integrins and the actin cytoskeleton. Through this linkage, talin is at the origin of mechanosignaling occurring at the plasma membrane-cytoskeleton interface. Despite its central position, talin is not able to fulfill its tasks alone, but requires help from kindlin and paxillin to detect and transform the mechanical tension along the integrin-talin-F-actin axis into intracellular signaling. The talin head forms a classical FERM domain, which is required to bind and regulate the conformation of the integrin receptor, as well as to induce intracellular force sensing. The FERM domain allows the strategic positioning of protein-protein and protein-lipid interfaces, including the membrane-binding and integrin affinity-regulating F1 loop, as well as the interaction with lipid-anchored Rap1 (Rap1a and Rap1b in mammals) GTPase. Here, we summarize the structural and regulatory features of talin and explain how it regulates cell adhesion and force transmission, as well as intracellular signaling at integrin-containing cell-matrix attachment sites.
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Affiliation(s)
- Michael Bachmann
- Department of Cell Physiology and Metabolism, Centre Médical Universitaire, 1211 Geneva 4, Switzerland
| | - Baihao Su
- Molecular Therapeutics Program, Fox Chase Cancer Center, 333 Cottman Ave, Philadelphia, PA 19111, USA
| | - Rolle Rahikainen
- Faculty of Medicine and Health Technology, Arvo Ylpön katu 34, Tampere University, FI-33520 Tampere, Finland
| | - Vesa P. Hytönen
- Faculty of Medicine and Health Technology, Arvo Ylpön katu 34, Tampere University, FI-33520 Tampere, Finland
- Fimlab Laboratories, Biokatu 4, FI-33520 Tampere, Finland
| | - Jinhua Wu
- Molecular Therapeutics Program, Fox Chase Cancer Center, 333 Cottman Ave, Philadelphia, PA 19111, USA
| | - Bernhard Wehrle-Haller
- Department of Cell Physiology and Metabolism, Centre Médical Universitaire, 1211 Geneva 4, Switzerland
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6
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Zhang H, Mao Z, Yang Z, Nakamura F. Identification of Filamin A Mechanobinding Partner III: SAV1 Specifically Interacts with Filamin A Mechanosensitive Domain 21. Biochemistry 2023; 62:1197-1208. [PMID: 36857526 DOI: 10.1021/acs.biochem.2c00665] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
Filamin A (FLNA) cross-links actin filaments and mediates mechanotransduction by force-induced conformational changes of its domains. FLNA's mechanosensitive immunoglobulin-like repeats (R) interact with each other to create cryptic binding sites, which can be exposed by physiologically relevant mechanical forces. Using the FLNA mechanosensing domains as an affinity ligand followed by stable isotope labeling by amino acids in cell culture (SILAC)-based proteomics, we recently identified smoothelin and fimbacin as FLNA mechanobinding proteins. Here, using the mechanosensing domain as an affinity ligand and two labeled amino acids, we identify salvador homologue 1 (SAV1), a component of the Hippo pathway kinase cascade, as a new FLNA mechanobinding partner. We demonstrate that SAV1 specifically interacts with the cryptic C-D cleft of FLNA R21 and map the FLNA-binding site on SAV1. We show that point mutations on the R21 C strand block the SAV1 interaction and find that SAV1 contains a FLNA-binding motif in the central region (116Phe-124Val). Point mutations F116A and T118A (FT/AA) disrupt the interaction. A proximity ligation assay reveals that their interaction occurs in the cytosol in an actin polymerization-dependent manner. Although SAV1 is typically found in the cytosol, disrupting the interaction between SAV1 and FLNA causes SAV1 to diffuse to the nucleus and YAP1 to diffuse to the cytosol in an inverse relationship. These results suggest that FLNA mediates regulation of the Hippo pathway through actin polymerization-dependent interaction with SAV1.
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Affiliation(s)
- Huaguan Zhang
- School of Pharmaceutical Science and Technology, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China
| | - Zhenfeng Mao
- School of Pharmaceutical Science and Technology, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China
| | - Ziwei Yang
- School of Pharmaceutical Science and Technology, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China
| | - Fumihiko Nakamura
- School of Pharmaceutical Science and Technology, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China
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7
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Feng Z, Mao Z, Yang Z, Liu X, Nakamura F. The force-dependent filamin A-G3BP1 interaction regulates phase-separated stress granule formation. J Cell Sci 2023; 136:297259. [PMID: 36806943 DOI: 10.1242/jcs.260684] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 02/03/2023] [Indexed: 02/22/2023] Open
Abstract
Filamin A (FLNA) is an actin crosslinking protein that mediates mechanotransduction. External and internal mechanical forces, through the actin cytoskeleton, can induce conformational changes of the FLNA molecule to expose cryptic binding sites for its binding partners. Here, we identified Ras GTPase-activating protein SH3 domain-binding protein 1 (G3BP1) as a new FLNA mechanobinding partner. Unlike other FLNA binding partners to the mechanosensing domain repeat 21 (R21), G3BP1 requires an additional neighboring repeat R22 to interact. We demonstrated that their interaction occurs in the cytosol of living cells in an actin polymerization-dependent manner. We also mapped the FLNA-binding site on G3BP1 and found that a F360A point mutation in the RNA recognition motif disrupts the interaction. RNA interfered with the FLNA-G3BP1 interaction, and FLNA did not localize in RNA-rich stress granules (SGs). Disruption of the interaction was sufficient to promote phase-separated SG formation, and arsenite treatment further stimulated the formation of SGs. Taken together, these data identify G3BP1 as a new mechanobinding protein that interacts with the FLNA mechanosensing domain R21 and suggest that SG formation is partially regulated by mechanical force.
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Affiliation(s)
- Ziyi Feng
- School of Pharmaceutical Science and Technology, Life Science Platform, Tianjin University, 92 Weijin Road, Nankai District, Tianjin, 300072, China
| | - Zhenfeng Mao
- School of Pharmaceutical Science and Technology, Life Science Platform, Tianjin University, 92 Weijin Road, Nankai District, Tianjin, 300072, China
| | - Ziwei Yang
- School of Pharmaceutical Science and Technology, Life Science Platform, Tianjin University, 92 Weijin Road, Nankai District, Tianjin, 300072, China
| | - Xiaowei Liu
- School of Pharmaceutical Science and Technology, Life Science Platform, Tianjin University, 92 Weijin Road, Nankai District, Tianjin, 300072, China
| | - Fumihiko Nakamura
- School of Pharmaceutical Science and Technology, Life Science Platform, Tianjin University, 92 Weijin Road, Nankai District, Tianjin, 300072, China
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8
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De Silva E, Hong F, Falet H, Kim H. Filamin A in platelets: Bridging the (signaling) gap between the plasma membrane and the actin cytoskeleton. Front Mol Biosci 2022; 9:1060361. [PMID: 36605989 PMCID: PMC9808056 DOI: 10.3389/fmolb.2022.1060361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 11/30/2022] [Indexed: 12/24/2022] Open
Abstract
Platelets are anucleate cells that are essential for hemostasis and wound healing. Upon activation of the cell surface receptors by their corresponding extracellular ligands, platelets undergo rapid shape change driven by the actin cytoskeleton; this shape change reaction is modulated by a diverse array of actin-binding proteins. One actin-binding protein, filamin A (FLNA), cross-links and stabilizes subcortical actin filaments thus providing stability to the cell membrane. In addition, FLNA binds the intracellular portion of multiple cell surface receptors and acts as a critical intracellular signaling scaffold that integrates signals between the platelet's plasma membrane and the actin cytoskeleton. This mini-review summarizes how FLNA transduces critical cell signals to the platelet cytoskeleton.
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Affiliation(s)
- Enoli De Silva
- Centre for Blood Research, University of British Columbia, Vancouver, BC, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Felix Hong
- Centre for Blood Research, University of British Columbia, Vancouver, BC, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Hervé Falet
- Versiti Blood Research Institute, Milwaukee, WI, United States
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Hugh Kim
- Centre for Blood Research, University of British Columbia, Vancouver, BC, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
- Department of Oral Biological and Medical Sciences, University of British Columbia, Vancouver, BC, Canada
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Zieba J, Forlenza KN, Heard K, Martin JH, Bosakova M, Cohn DH, Robertson SP, Krejci P, Krakow D. Intervertebral disc degeneration is rescued by TGFβ/BMP signaling modulation in an ex vivo filamin B mouse model. Bone Res 2022; 10:37. [PMID: 35474298 PMCID: PMC9042866 DOI: 10.1038/s41413-022-00200-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 11/01/2021] [Accepted: 01/06/2022] [Indexed: 12/14/2022] Open
Abstract
Spondylocarpotarsal syndrome (SCT) is a rare musculoskeletal disorder characterized by short stature and vertebral, carpal, and tarsal fusions resulting from biallelic nonsense mutations in the gene encoding filamin B (FLNB). Utilizing a FLNB knockout mouse, we showed that the vertebral fusions in SCT evolved from intervertebral disc (IVD) degeneration and ossification of the annulus fibrosus (AF), eventually leading to full trabecular bone formation. This resulted from alterations in the TGFβ/BMP signaling pathway that included increased canonical TGFβ and noncanonical BMP signaling. In this study, the role of FLNB in the TGFβ/BMP pathway was elucidated using in vitro, in vivo, and ex vivo treatment methodologies. The data demonstrated that FLNB interacts with inhibitory Smads 6 and 7 (i-Smads) to regulate TGFβ/BMP signaling and that loss of FLNB produces increased TGFβ receptor activity and decreased Smad 1 ubiquitination. Through the use of small molecule inhibitors in an ex vivo spine model, TGFβ/BMP signaling was modulated to design a targeted treatment for SCT and disc degeneration. Inhibition of canonical and noncanonical TGFβ/BMP pathway activity restored Flnb-/- IVD morphology. These most effective improvements resulted from specific inhibition of TGFβ and p38 signaling activation. FLNB acts as a bridge for TGFβ/BMP signaling crosstalk through i-Smads and is key for the critical balance in TGFβ/BMP signaling that maintains the IVD. These findings further our understanding of IVD biology and reveal new molecular targets for disc degeneration as well as congenital vertebral fusion disorders.
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Affiliation(s)
- Jennifer Zieba
- Department of Orthopedic Surgery, Los Angeles, CA, 90095, USA
| | | | - Kelly Heard
- Department of Orthopedic Surgery, Los Angeles, CA, 90095, USA
| | - Jorge H Martin
- Department of Orthopedic Surgery, Los Angeles, CA, 90095, USA
| | - Michaela Bosakova
- Department of Biology, Faculty of Medicine, Masaryk University, 62500, Brno, Czech Republic
- International Clinical Research Center, St. Anne's University Hospital, 65691, Brno, Czech Republic
- Institute of Animal Physiology and Genetics, Czech Academy of Sciences, 60200, Brno, Czech Republic
| | - Daniel H Cohn
- Department of Orthopedic Surgery, Los Angeles, CA, 90095, USA
- Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Stephen P Robertson
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Pavel Krejci
- Department of Biology, Faculty of Medicine, Masaryk University, 62500, Brno, Czech Republic
- International Clinical Research Center, St. Anne's University Hospital, 65691, Brno, Czech Republic
- Institute of Animal Physiology and Genetics, Czech Academy of Sciences, 60200, Brno, Czech Republic
| | - Deborah Krakow
- Department of Orthopedic Surgery, Los Angeles, CA, 90095, USA.
- Department of Human Genetics, Los Angeles, CA, 90095, USA.
- Department of Obstetrics and Gynecology, Los Angeles, CA, 90095, USA.
- Department of Pediatrics, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, CA, 90095, USA.
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An N, Hou R, Liu Y, Han P, Zhao W, Wu W, Lu S, Ji H, Dong J. Application of iTRAQ Technology to Identify Differentially Expressed Proteins of Sauce Lamb Tripe with Different Secondary Pasteurization Treatments. Foods 2022; 11:foods11081166. [PMID: 35454754 PMCID: PMC9032106 DOI: 10.3390/foods11081166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 04/12/2022] [Accepted: 04/14/2022] [Indexed: 02/04/2023] Open
Abstract
Vacuum-packed sauce lamb tripe was subjected to secondary pasteurization by high-pressure processing (HPP) and heat treatment (HT), and iTRAQ technology was applied to investigate the differentially expressed proteins (DEPs). The analysis revealed 484 and 398 DEPs in the HPP and HT samples, respectively, compared with no treatment. These DEPs were sorted by texture results, and it was revealed that these DEPs acted in different biological processes with many structural proteins and protein subunits related to lamb tripe texture. The results verified by Western blot were consistent with the protein expression changes observed by proteomics. The bioinformatics analysis showed that the hardness and gumminess of the sauce lamb tripe after HT might be related to changes in the expression of CNN1 and FN1. The changes in the expression of TMP, FN1, YWHAG, TTN, collagen isoforms, and ARPC3 might be related to the improved springiness and chewiness of lamb tripe after HPP.
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Affiliation(s)
- Ning An
- College of Food Quality and Safety, Shihezi University, Shihezi 832000, China; (N.A.); (R.H.); (P.H.); (W.W.); (S.L.); (H.J.)
| | - Ran Hou
- College of Food Quality and Safety, Shihezi University, Shihezi 832000, China; (N.A.); (R.H.); (P.H.); (W.W.); (S.L.); (H.J.)
| | - Yangming Liu
- Sesame Research Center, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China;
| | - Ping Han
- College of Food Quality and Safety, Shihezi University, Shihezi 832000, China; (N.A.); (R.H.); (P.H.); (W.W.); (S.L.); (H.J.)
| | - Wei Zhao
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China;
| | - Wenxia Wu
- College of Food Quality and Safety, Shihezi University, Shihezi 832000, China; (N.A.); (R.H.); (P.H.); (W.W.); (S.L.); (H.J.)
| | - Shiling Lu
- College of Food Quality and Safety, Shihezi University, Shihezi 832000, China; (N.A.); (R.H.); (P.H.); (W.W.); (S.L.); (H.J.)
| | - Hua Ji
- College of Food Quality and Safety, Shihezi University, Shihezi 832000, China; (N.A.); (R.H.); (P.H.); (W.W.); (S.L.); (H.J.)
| | - Juan Dong
- College of Food Quality and Safety, Shihezi University, Shihezi 832000, China; (N.A.); (R.H.); (P.H.); (W.W.); (S.L.); (H.J.)
- Correspondence: ; Tel.: +86-099-3205-8735; Fax: +86-099-3205-7399
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11
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Quiggle A, Charng WL, Antunes L, Nikolov M, Bledsoe X, Hecht JT, Dobbs MB, Gurnett CA. Whole Exome Sequencing in Individuals with Idiopathic Clubfoot Reveals a Recurrent Filamin B (FLNB) Deletion. Clin Orthop Relat Res 2022; 480:421-430. [PMID: 34491919 PMCID: PMC8747482 DOI: 10.1097/corr.0000000000001957] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 08/11/2021] [Indexed: 02/03/2023]
Abstract
BACKGROUND Clubfoot, a congenital deformity that presents as a rigid, inward turning of the foot, affects approximately 1 in 1000 infants and occurs as an isolated birth defect in 80% of patients. Despite its high level of heritability, few causative genes have been identified, and mutations in known genes are only responsible for a small portion of clubfoot heritability. QUESTIONS/PURPOSES (1) Are any rare gene variants enriched (that is, shared) in unrelated patients with isolated clubfoot? (2) Are there other rare variants in the identified gene (Filamin B) in these patients with clubfoot? METHODS Whole-exome sequence data were generated from a discovery cohort of 183 unrelated probands with clubfoot and 2492 controls. Variants were filtered with minor allele frequency < 0.02 to identify rare variants as well as small insertions and deletions (indels) resulting in missense variants, nonsense or premature truncation, or in-frame deletions. A candidate deletion was then genotyped in another cohort of 974 unrelated patients with clubfoot (a replication cohort). Other rare variants in the candidate gene were also investigated. A segregation analysis was performed in multigenerational families of individuals with clubfoot to see if the genotypes segregate with phenotypes. Single-variant association analysis was performed using the Fisher two-tailed exact test (exact p values are presented to give an indication of the magnitude of the association). RESULTS There were no recurrent variants in the known genes causing clubfoot in this study. A three-base pair in-frame codon deletion of Filamin B (FLNB) (p.E1792del, rs1470699812) was identified in 1.6% (3 of 183) of probands with clubfoot in the discovery cohort compared with 0% of controls (0 of 2492) (odds ratio infinity (inf) [95% CI 5.64 to inf]; p = 3.18 x 10-5) and 0.0016% of gnomAD controls (2 of 125,709) (OR 1.01 x 103 [95% CI 117.42 to 1.64 x 104]; p = 3.13 x 10-8). By screening a replication cohort (n = 974 patients), we found two probands with the identical FLNB deletion. In total, the deletion was identified in 0.43% (5 of 1157) of probands with clubfoot compared with 0% of controls and 0.0016% of gnomAD controls (OR 268.5 [95% CI 43.68 to 2.88 x 103]; p = 1.43 x 10-9). The recurrent FLNB p.E1792del variant segregated with clubfoot, with incomplete penetrance in two families. Affected individuals were more likely to be male and have bilateral clubfoot. Although most patients had isolated clubfoot, features consistent with Larsen syndrome, including upper extremity abnormalities such as elbow and thumb hypermobility and wide, flat thumbs, were noted in affected members of one family. We identified 19 additional rare FLNB missense variants located throughout the gene in patients with clubfoot. One of these missense variants, FLNB p.G2397D, exhibited incomplete penetrance in one family. CONCLUSION A recurrent FLNB E1792 deletion was identified in 0.43% of 1157 isolated patients with clubfoot. Given the absence of any recurrent variants in our discovery phase (n = 183) for any of the known genes causing clubfoot, our findings support that novel and rare missense variants in FLNB in patients with clubfoot, although rare, may be among the most commonly known genetic causes of clubfoot. Patients with FLNB variants often have isolated clubfoot, but they and their family members may be at an increased risk of having additional clinical features consistent with Larsen syndrome. CLINICAL RELEVANCE Identification of FLNB variants may be useful for determining clubfoot recurrence risk and comorbidities.
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Affiliation(s)
- Ashley Quiggle
- Department of Orthopaedic Surgery, Washington University in St. Louis, St. Louis, MO, USA
| | - Wu-Lin Charng
- Department of Neurology, Washington University in St. Louis, St. Louis, MO, USA
| | - Lilian Antunes
- Department of Orthopaedic Surgery, Washington University in St. Louis, St. Louis, MO, USA
| | - Momchil Nikolov
- Department of Neurology, Washington University in St. Louis, St. Louis, MO, USA
| | - Xavier Bledsoe
- Department of Neurology, Washington University in St. Louis, St. Louis, MO, USA
| | - Jacqueline T. Hecht
- Department of Pediatrics, McGovern Medical School and School of Dentistry, the University of Texas Health Science Center at Houston, Houston, TX, USA
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12
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Treppiedi D, Catalano R, Mangili F, Mantovani G, Peverelli E. Role of filamin A in the pathogenesis of neuroendocrine tumors and adrenal cancer. ENDOCRINE ONCOLOGY (BRISTOL, ENGLAND) 2022; 2:R143-R152. [PMID: 37435454 PMCID: PMC10259351 DOI: 10.1530/eo-22-0055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 10/28/2022] [Indexed: 07/13/2023]
Abstract
Cell cytoskeleton proteins are involved in tumor pathogenesis, progression and pharmacological resistance. Filamin A (FLNA) is a large actin-binding protein with both structural and scaffold functions implicated in a variety of cellular processes, including migration, cell adhesion, differentiation, proliferation and transcription. The role of FLNA in cancers has been studied in multiple types of tumors. FLNA plays a dual role in tumors, depending on its subcellular localization, post-translational modification (as phosphorylation at Ser2125) and interaction with binding partners. This review summarizes the experimental evidence showing the critical involvement of FLNA in the complex biology of endocrine tumors. Particularly, the role of FLNA in regulating expression and signaling of the main pharmacological targets in pituitary neuroendocrine tumors, pancreatic neuroendocrine tumors, pulmonary neuroendocrine tumors and adrenocortical carcinomas, with implications on responsiveness to currently used drugs in the treatment of these tumors, will be discussed.
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Affiliation(s)
- Donatella Treppiedi
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Rosa Catalano
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Federica Mangili
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Giovanna Mantovani
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Erika Peverelli
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
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13
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Structure and Function of Filamin C in the Muscle Z-Disc. Int J Mol Sci 2020; 21:ijms21082696. [PMID: 32295012 PMCID: PMC7216277 DOI: 10.3390/ijms21082696] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 04/08/2020] [Accepted: 04/09/2020] [Indexed: 12/22/2022] Open
Abstract
Filamin C (FLNC) is one of three filamin proteins (Filamin A (FLNA), Filamin B (FLNB), and FLNC) that cross-link actin filaments and interact with numerous binding partners. FLNC consists of a N-terminal actin-binding domain followed by 24 immunoglobulin-like repeats with two intervening calpain-sensitive hinges separating R15 and R16 (hinge 1) and R23 and R24 (hinge-2). The FLNC subunit is dimerized through R24 and calpain cleaves off the dimerization domain to regulate mobility of the FLNC subunit. FLNC is localized in the Z-disc due to the unique insertion of 82 amino acid residues in repeat 20 and necessary for normal Z-disc formation that connect sarcomeres. Since phosphorylation of FLNC by PKC diminishes the calpain sensitivity, assembly, and disassembly of the Z-disc may be regulated by phosphorylation of FLNC. Mutations of FLNC result in cardiomyopathy and muscle weakness. Although this review will focus on the current understanding of FLNC structure and functions in muscle, we will also discuss other filamins because they share high sequence similarity and are better characterized. We will also discuss a possible role of FLNC as a mechanosensor during muscle contraction.
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14
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Abstract
Integrins are heterodimeric cell surface receptors ensuring the mechanical connection between cells and the extracellular matrix. In addition to the anchorage of cells to the extracellular matrix, these receptors have critical functions in intracellular signaling, but are also taking center stage in many physiological and pathological conditions. In this review, we provide some historical, structural, and physiological notes so that the diverse functions of these receptors can be appreciated and put into the context of the emerging field of mechanobiology. We propose that the exciting journey of the exploration of these receptors will continue for at least another new generation of researchers.
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Affiliation(s)
- Michael Bachmann
- Department of Cell Physiology and Metabolism, University of Geneva, Centre Médical Universitaire , Geneva , Switzerland ; and Faculty of Medicine and Health Technology, Tampere University, and Fimlab Laboratories , Tampere , Finland
| | - Sampo Kukkurainen
- Department of Cell Physiology and Metabolism, University of Geneva, Centre Médical Universitaire , Geneva , Switzerland ; and Faculty of Medicine and Health Technology, Tampere University, and Fimlab Laboratories , Tampere , Finland
| | - Vesa P Hytönen
- Department of Cell Physiology and Metabolism, University of Geneva, Centre Médical Universitaire , Geneva , Switzerland ; and Faculty of Medicine and Health Technology, Tampere University, and Fimlab Laboratories , Tampere , Finland
| | - Bernhard Wehrle-Haller
- Department of Cell Physiology and Metabolism, University of Geneva, Centre Médical Universitaire , Geneva , Switzerland ; and Faculty of Medicine and Health Technology, Tampere University, and Fimlab Laboratories , Tampere , Finland
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15
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Wang J, Nakamura F. Identification of Filamin A Mechanobinding Partner II: Fimbacin Is a Novel Actin Cross-Linking and Filamin A Binding Protein. Biochemistry 2019; 58:4737-4743. [PMID: 30990684 DOI: 10.1021/acs.biochem.9b00101] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Filamin A (FLNA), an actin cross-linking protein, acts as a mechanosensor and mechanotransducer by exposing the cryptic binding site on repeat 21 (R21) to interact with integrin. Here, we investigated if any other biological molecule interacts with the cryptic binding site. Using proteomics and an in silico screening for a FLNA-binding motif, we identified and characterized a protein termed fimbacin (filamin mechanobinding actin cross-linking protein), encoded in the LUZP1 gene, as a novel FLNA-binding partner. Fimbacin does not interact with canonical full-length FLNA, but the exposure of a cryptic integrin-binding site of FLNA R21 enables fimbacin to interact. We have identified two FLNA binding sites on fimbacin and determined critical amino acid residues for the interaction. We also found that fimbacin itself is a new actin cross-linking protein and mapped the actin-binding site on amino acid residues 400-500. Fimbacin oligomerizes (estimated as an octamer on size exclusion chromatography) through the amino-terminal domain that is predicted to be a coiled-coil to cross-link actin filaments. When expressed, fimbacin localized to actin stress fibers in tissue culture cells. Although the interaction with FLNA is not necessary for fimbacin to colocalize with F-actin, fluorescent recovery after photobleaching (FRAP) revealed that their interaction stabilizes fimbacin on the actin cytoskeleton and that inhibition of Rho-kinase, an upstream activator of myosin II, also decreases the interaction presumably due to a loss of internal mechanical stress. Taken together, these data identify fimbacin as a new actin cross-linking protein that interacts with the FLNA mechanosensing domain R21.
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Affiliation(s)
- Jiale Wang
- School of Pharmaceutical Science and Technology, Life Science Platform , Tianjin University , 92 Weijin Road, Nankai District , Tianjin , 300072 , China
| | - Fumihiko Nakamura
- School of Pharmaceutical Science and Technology, Life Science Platform , Tianjin University , 92 Weijin Road, Nankai District , Tianjin , 300072 , China
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16
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Wang L, Nakamura F. Identification of Filamin A Mechanobinding Partner I: Smoothelin Specifically Interacts with the Filamin A Mechanosensitive Domain 21. Biochemistry 2019; 58:4726-4736. [PMID: 30990690 DOI: 10.1021/acs.biochem.9b00100] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Filamin A (FLNA) is a ubiquitously expressed actin cross-linking protein and a scaffold of numerous binding partners to regulate cell proliferation, migration, and survival. FLNA is a homodimer, and each subunit has an N-terminal actin-binding domain followed by 24 immunoglobulin-like repeats (R). FLNA mediates mechanotransduction by force-induced conformational changes of its cryptic integrin-binding site on R21. Here, we identified two novel FLNA-binding partners, smoothelins (SMTN A and B) and leucine zipper protein 1 (LUZP1), using stable isotope labeling by amino acids in cell culture (SILAC)-based proteomics followed by an in silico screening for proteins having a consensus FLNA-binding domain. We found that, although SMTN does not interact with full-length FLNA, it binds to FLNA variant 1 (FLNAvar-1) that exposes the cryptic CD cleft of R21. Point mutations on the C strand that disrupt the integrin binding also block the SMTN interaction. We identified FLNA-binding domains on SMTN using mutagenesis and used the mutant SMTN to investigate the role of the FLNA-SMTN interaction on the dynamics and localization of SMTN in living cells. Fluorescence recovery after photobleaching (FRAP) of GFP-labeled SMTN in living cells demonstrated that the non-FLNA-binding mutant SMTN diffuses faster than wild-type SMTN. Moreover, inhibition of Rho-kinase using Y27632 also increases the diffusion. These data demonstrated that SMTN specifically interacts with FLNAvar-1 and mechanically activated FLNA in cells. The companion report (Wang and Nakamura, 2019) describes the interactions of FLNA with the transcript of the LUZP1 gene.
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Affiliation(s)
- Lina Wang
- School of Pharmaceutical Science and Technology, Life Science Platform , Tianjin University , 92 Weijin Road , Nankai District, Tianjin 300072 , China
| | - Fumihiko Nakamura
- School of Pharmaceutical Science and Technology, Life Science Platform , Tianjin University , 92 Weijin Road , Nankai District, Tianjin 300072 , China
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17
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Mantovani G, Treppiedi D, Giardino E, Catalano R, Mangili F, Vercesi P, Arosio M, Spada A, Peverelli E. Cytoskeleton actin-binding proteins in clinical behavior of pituitary tumors. Endocr Relat Cancer 2019; 26:R95-R108. [PMID: 30589642 DOI: 10.1530/erc-18-0442] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 12/04/2018] [Indexed: 12/16/2022]
Abstract
Although generally benign, pituitary tumors are frequently locally invasive, with reduced success of neurosurgery and unresponsive to pharmacological treatment with somatostatin or dopamine analogues. The molecular basis of the different biological behavior of pituitary tumors are still poorly identified, but a body of work now suggests that the activity of specific cytoskeleton proteins is a key factor regulating both the invasiveness and drug resistance of these tumors. This review recapitulates the experimental evidence supporting a role for the actin-binding protein filamin A (FLNA) in the regulation of somatostatin and dopamine receptors expression and signaling in pituitary tumors, thus in determining the responsiveness to currently used drugs, somatostatin analogues and dopamine receptor type 2 agonists. Regarding the regulation of invasive behavior of pituitary tumoral cells, we bring evidence to the role of the actin-severing protein cofilin, whose activation status may be modulated by dopaminergic and somatostatinergic drugs, through FLNA involvement. Molecular mechanisms involved in the regulation of FLNA expression and function in pituitary tumors will also be discussed.
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Affiliation(s)
- G Mantovani
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - D Treppiedi
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - E Giardino
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - R Catalano
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
- PhD Program in Endocrinological Sciences, Sapienza University of Rome, Rome, Italy
| | - F Mangili
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - P Vercesi
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - M Arosio
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - A Spada
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - E Peverelli
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
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18
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Li J, Choi PS, Chaffer CL, Labella K, Hwang JH, Giacomelli AO, Kim JW, Ilic N, Doench JG, Ly SH, Dai C, Hagel K, Hong AL, Gjoerup O, Goel S, Ge JY, Root DE, Zhao JJ, Brooks AN, Weinberg RA, Hahn WC. An alternative splicing switch in FLNB promotes the mesenchymal cell state in human breast cancer. eLife 2018; 7:37184. [PMID: 30059005 PMCID: PMC6103745 DOI: 10.7554/elife.37184] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Accepted: 07/24/2018] [Indexed: 12/14/2022] Open
Abstract
Alternative splicing of mRNA precursors represents a key gene expression regulatory step and permits the generation of distinct protein products with diverse functions. In a genome-scale expression screen for inducers of the epithelial-to-mesenchymal transition (EMT), we found a striking enrichment of RNA-binding proteins. We validated that QKI and RBFOX1 were necessary and sufficient to induce an intermediate mesenchymal cell state and increased tumorigenicity. Using RNA-seq and eCLIP analysis, we found that QKI and RBFOX1 coordinately regulated the splicing and function of the actin-binding protein FLNB, which plays a causal role in the regulation of EMT. Specifically, the skipping of FLNB exon 30 induced EMT by releasing the FOXC1 transcription factor. Moreover, skipping of FLNB exon 30 is strongly associated with EMT gene signatures in basal-like breast cancer patient samples. These observations identify a specific dysregulation of splicing, which regulates tumor cell plasticity and is frequently observed in human cancer. As the human body develops, countless cells change from one state into another. Two important cell states are known as epithelial and mesenchymal. Cells in the epithelial state tend to be tightly connected and form barriers, like skin cells. Mesenchymal state cells are loosely organized, move around more and make up connective tissues. Some cells alternate between these states via an epithelial-to-mesenchymal transition (EMT for short) and back again. Without this transition, certain organs would not develop and wounds would not heal. Yet, cancer cells also use this transition to spread to distant sites of the body. Such cancers are often the most aggressive, and therefore the most deadly. The epithelial-to-mesenchymal transition is dynamically regulated in a reversible manner. For example, the genes for some proteins might only be active in the epithelial state and further reinforce this state by turning on other ‘epithelial genes’. Alternatively, there might be differences in the processing of mRNA molecules – the intermediate molecules between DNA and protein – that result in the production of different proteins in epithelial and mesenchymal cells. Li, Choi et al. wanted to know which of the thousands of human genes can endow epithelial state cells with mesenchymal characteristics. A better understanding of the switch could help to prevent cancers undergoing an epithelial-to-mesenchymal transition. From a large-scale experiment in human breast cancer cells, Li, Choi et al. found that a group of proteins that bind and modify mRNA molecules are important for the epithelial-to-mesenchymal transition. Two proteins in particular promoted the transition, most likely by binding to the mRNA of a third protein called FLNB and removing a small piece of it. FLNB normally works to prevent the epithelial-to-mesenchymal transition, but the smaller protein encoded by the shorter mRNA promoted the transition by turning on ‘mesenchymal genes’. This switching between different FLNB proteins happens in some of the more aggressive breast cancers, which also contain mesenchymal cells. Finding out which FLNB protein is made in a given cancer may provide an indication of its aggressiveness. Also, looking for drugs that can target the mRNA-binding proteins or FLNB may one day lead to new treatments for some of the most aggressive breast cancers.
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Affiliation(s)
- Ji Li
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, United States.,Harvard Medical School, Boston, United States.,Broad Institute of MIT and Harvard, Cambridge, United States
| | - Peter S Choi
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, United States.,Harvard Medical School, Boston, United States.,Broad Institute of MIT and Harvard, Cambridge, United States
| | - Christine L Chaffer
- Whitehead Institute for Biomedical Research and MIT, Cambridge, United States.,Garvan Institute of Medical Research, Sydney, Australia
| | - Katherine Labella
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, United States.,Harvard Medical School, Boston, United States
| | - Justin H Hwang
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, United States.,Harvard Medical School, Boston, United States.,Broad Institute of MIT and Harvard, Cambridge, United States
| | - Andrew O Giacomelli
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, United States.,Harvard Medical School, Boston, United States.,Broad Institute of MIT and Harvard, Cambridge, United States
| | - Jong Wook Kim
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, United States.,Harvard Medical School, Boston, United States.,Broad Institute of MIT and Harvard, Cambridge, United States
| | - Nina Ilic
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, United States.,Harvard Medical School, Boston, United States.,Broad Institute of MIT and Harvard, Cambridge, United States
| | - John G Doench
- Broad Institute of MIT and Harvard, Cambridge, United States
| | - Seav Huong Ly
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, United States.,Harvard Medical School, Boston, United States.,Broad Institute of MIT and Harvard, Cambridge, United States
| | - Chao Dai
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, United States.,Harvard Medical School, Boston, United States.,Broad Institute of MIT and Harvard, Cambridge, United States
| | - Kimberly Hagel
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, United States.,Harvard Medical School, Boston, United States
| | - Andrew L Hong
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, United States.,Harvard Medical School, Boston, United States.,Broad Institute of MIT and Harvard, Cambridge, United States
| | - Ole Gjoerup
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, United States.,Harvard Medical School, Boston, United States.,Broad Institute of MIT and Harvard, Cambridge, United States
| | - Shom Goel
- Harvard Medical School, Boston, United States.,Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, United States
| | - Jennifer Y Ge
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, United States.,Harvard Medical School, Boston, United States.,Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, United States
| | - David E Root
- Broad Institute of MIT and Harvard, Cambridge, United States
| | - Jean J Zhao
- Harvard Medical School, Boston, United States.,Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, United States
| | - Angela N Brooks
- University of California, Santa Cruz, Santa Cruz, United States
| | - Robert A Weinberg
- Whitehead Institute for Biomedical Research and MIT, Cambridge, United States
| | - William C Hahn
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, United States.,Harvard Medical School, Boston, United States.,Broad Institute of MIT and Harvard, Cambridge, United States
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19
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Xu Q, Wu N, Cui L, Lin M, Thirumal Kumar D, George Priya Doss C, Wu Z, Shen J, Song X, Qiu G. Comparative analysis of the two extremes of FLNB-mutated autosomal dominant disease spectrum: from clinical phenotypes to cellular and molecular findings. Am J Transl Res 2018; 10:1400-1412. [PMID: 29887954 PMCID: PMC5992551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Accepted: 04/18/2018] [Indexed: 06/08/2023]
Abstract
Non-randomly distributed missense mutations of Filamin B (FLNB) can lead to a spectrum of autosomal dominant-inherited skeletal malformations caused by bone hypoplasia, including Larsen syndrome (LS), atelosteogenesi-I (AO-I), atelosteogenesi-I (AO-III) and boomerang dysplasia (BD). Among this spectrum of diseases, LS causes a milder hypoplasia of the skeletal system, compared to BD's much more severe symptoms. Previous studies revealed limited molecular mechanisms of FLNB-related diseases but most of them were carried out with HEK293 cells from the kidney which could not reproduce FLNB's specificity to skeletal tissues. Instead, we elected to use ATDC5, a chondrogenic stem cell line widely used to study endochondral osteogenesis. In this study, we established FLNB-transfected ATDC5 cell model. We reported a pedigree of LS with mutation of FLNBG1586R and reviewed a case of BD with mutation of FLNBL171R . Using the ATDC5 cell model above, we compared cellular and molecular phenotypes of BD-associated FLNBL171R and LS-associated FLNBG1586R . We found that while both phenotypes had an increased expression of Runx2, FLNBL171R-expressing ATDC5 cells presented globular aggregation of FLNB protein and increased cellular apoptosis rate while FLNBG1586R-expressing ATDC5 cells presented evenly distributed FLNB protein and decreased cellular migration. These findings support our explanation for the cause of differences in clinical phenotypes between LS and BD. Our study makes a comparative analysis of two extremes of the FLNB-mutated autosomal dominant spectrum, relating known clinical phenotypes to our new cellular and molecular findings. These results indicated next steps for future research on the role of FLNB in the physiological process of endochondral osteogenesis.
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Affiliation(s)
- Qiming Xu
- Department of Orthopedic Surgery, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical SciencesBeijing, China
| | - Nan Wu
- Department of Orthopedic Surgery, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical SciencesBeijing, China
- Beijing Key Laboratory for Genetic Research of Skeletal DeformityBeijing, China
- Medical Research Center of Orthopedics, Chinese Academy of Medical SciencesBeijing, China
| | - Lijia Cui
- Department of Endocrinology, Peking Union Medical College HospitalBeijing, China
| | - Mao Lin
- Department of Orthopedic Surgery, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical SciencesBeijing, China
| | - D Thirumal Kumar
- Department of Integrative Biology, Vellore Institute of TechnologyVellore, India
| | - C George Priya Doss
- Department of Integrative Biology, Vellore Institute of TechnologyVellore, India
| | - Zhihong Wu
- Department of Central Laboratory, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical SciencesBeijing, China
- Beijing Key Laboratory for Genetic Research of Skeletal DeformityBeijing, China
- Medical Research Center of Orthopedics, Chinese Academy of Medical SciencesBeijing, China
| | - Jianxiong Shen
- Department of Orthopedic Surgery, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical SciencesBeijing, China
- Beijing Key Laboratory for Genetic Research of Skeletal DeformityBeijing, China
- Medical Research Center of Orthopedics, Chinese Academy of Medical SciencesBeijing, China
| | - Xiangjian Song
- Department of Pediatric Orthopedics, Zhengzhou Orthopedic HospitalZhengzhou, Henan, China
| | - Guixing Qiu
- Department of Orthopedic Surgery, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical SciencesBeijing, China
- Beijing Key Laboratory for Genetic Research of Skeletal DeformityBeijing, China
- Medical Research Center of Orthopedics, Chinese Academy of Medical SciencesBeijing, China
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20
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Savarese M, Jonson PH, Huovinen S, Paulin L, Auvinen P, Udd B, Hackman P. The complexity of titin splicing pattern in human adult skeletal muscles. Skelet Muscle 2018; 8:11. [PMID: 29598826 PMCID: PMC5874998 DOI: 10.1186/s13395-018-0156-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 03/05/2018] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Mutations in the titin gene (TTN) cause a large spectrum of diseases affecting skeletal and/or cardiac muscle. TTN includes 363 coding exons, a repeated region with a high degree of complexity, isoform-specific elements, and metatranscript-only exons thought to be expressed only during fetal development. Although three main classes of isoforms have been described so far, alternative splicing events (ASEs) in different tissues or in different developmental and physiological states have been reported. METHODS To achieve a comprehensive view of titin ASEs in adult human skeletal muscles, we performed a RNA-Sequencing experiment on 42 human biopsies collected from 12 anatomically different skeletal muscles of 11 individuals without any skeletal-muscle disorders. RESULTS We confirmed that the skeletal muscle N2A isoforms are highly prevalent, but we found an elevated number of alternative splicing events, some at a very high level. These include previously unknown exon skipping events and alternative 5' and 3' splice sites. Our data suggests the partial inclusion in the TTN transcript of some metatranscript-only exons and the partial exclusion of canonical N2A exons. CONCLUSIONS This study provides an extensive picture of the complex TTN splicing pattern in human adult skeletal muscle, which is crucial for a proper clinical interpretation of TTN variants.
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Affiliation(s)
- Marco Savarese
- Folkhälsan Research Center, University of Helsinki, Helsinki, Finland. .,Folkhälsan Institute of Genetics, Department of Medical Genetics, University of Helsinki, Biomedicum, Haartmaninkatu 8, Pb 63, 00014, Helsinki, Finland.
| | - Per Harald Jonson
- Folkhälsan Research Center, University of Helsinki, Helsinki, Finland
| | - Sanna Huovinen
- Department of Pathology, Fimlab Laboratories, Tampere University Hospital, Tampere, Finland
| | - Lars Paulin
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Petri Auvinen
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Bjarne Udd
- Folkhälsan Research Center, University of Helsinki, Helsinki, Finland.,Department of Pathology, Fimlab Laboratories, Tampere University Hospital, Tampere, Finland.,Vaasa Central Hospital, Vaasa, Finland
| | - Peter Hackman
- Folkhälsan Research Center, University of Helsinki, Helsinki, Finland
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21
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Li Y, Sun Y, Sun F, Hua R, Li C, Chen L, Guo D, Mu J. Mechanisms and Effects on HBV Replication of the Interaction between HBV Core Protein and Cellular Filamin B. Virol Sin 2018; 33:162-172. [PMID: 29594956 DOI: 10.1007/s12250-018-0023-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 01/12/2018] [Indexed: 02/06/2023] Open
Abstract
Hepatitis B virus (HBV) infection is one of the major problems that threatens global health. There have been many studies on HBV, but the relationship between HBV and host factors is largely unexplored and more studies are needed to clarify these interactions. Filamin B is an actin-binding protein that acts as a cytoskeleton protein, and it is involved in cell development and several signaling pathways. In this study, we showed that filamin B interacted with HBV core protein, and the interaction promoted HBV replication. The interaction between filamin B and core protein was observed in HEK 293T, Huh7 and HepG2 cell lines by co-immunoprecipitation and co-localization immnofluoresence. Overexpression of filamin B increased the levels of HBV total RNAs and pre-genome RNA (pgRNA), and improved the secretion level of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg). In contrast, filamin B knockdown inhibited HBV replication, decreased the level of HBV total RNAs and pgRNA, and reduced the secretion level of HBsAg and HBeAg. In addition, we found that filamin B and core protein may interact with each other via four blocks of argentine residues at the C-terminus of core protein. In conclusion, we identify filamin B as a novel host factor that can interact with core protein to promote HBV replication in hepatocytes. Our study provides new insights into the relationship between HBV and host factors and may provide new strategies for the treatment of HBV infection.
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Affiliation(s)
- Yilin Li
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Yishuang Sun
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Fuyun Sun
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Rong Hua
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Chenlin Li
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Lang Chen
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Deyin Guo
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China. .,School of Basic Medicine (Shenzhen), Sun Yat-sen University, Guangzhou, 510081, China.
| | - Jingfang Mu
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China.
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22
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Tanabe K, Shinsato Y, Furukawa T, Kita Y, Hatanaka K, Minami K, Kawahara K, Yamamoto M, Baba K, Mori S, Uchikado Y, Maemura K, Tanimoto A, Natsugoe S. Filamin C promotes lymphatic invasion and lymphatic metastasis and increases cell motility by regulating Rho GTPase in esophageal squamous cell carcinoma. Oncotarget 2018; 8:6353-6363. [PMID: 28031525 PMCID: PMC5351637 DOI: 10.18632/oncotarget.14087] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 12/13/2016] [Indexed: 12/31/2022] Open
Abstract
To establish treatments to improve the prognosis of cancer patients, it is necessary to find new targets to control metastasis. We found that expression of FilaminC (FLNC), a member of the actin binding and cross-linking filamin protein family is correlated with lymphatic invasion and lymphatic metastasis in esophageal squamous cell carcinoma (ESCC) by increasing cell motility through activation of Rho GTPase. Immunohistochemistry analysis showed that FLNC expression in ESCC is associated with lymphatic invasion, metastasis, and prognosis. FLNC knockdown in esophageal cancer cell lines decreased cell migration in wound healing and transwell migration assays, and invasion in transwell migration assays. Furthermore, FLNC knockdown reduced the amount of activated Rac-1 (GTP-Rac1) and activated Cdc42 (GTP-Cdc42). Our results suggest that FLNC expression is a useful biomarker of ESCC metastatic tendency and that inhibiting FLNC function may be useful to control the metastasis of ESCC.
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Affiliation(s)
- Kan Tanabe
- Department of Digestive Surgery, Breast and Thyroid Surgery, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan.,Department of Molecular Oncology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Yoshinari Shinsato
- Department of Molecular Oncology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Tatsuhiko Furukawa
- Department of Molecular Oncology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan.,Center for the Research of Advanced Diagnosis and Therapy of Cancer, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Yoshiaki Kita
- Department of Digestive Surgery, Breast and Thyroid Surgery, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Kazuhito Hatanaka
- Department of Molecular and Cellular Pathology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Kentaro Minami
- Department of Molecular Oncology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Kohichi Kawahara
- Department of Molecular Oncology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Masatatsu Yamamoto
- Department of Molecular Oncology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Kenji Baba
- Department of Digestive Surgery, Breast and Thyroid Surgery, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Shinichiro Mori
- Department of Digestive Surgery, Breast and Thyroid Surgery, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Yasuto Uchikado
- Department of Digestive Surgery, Breast and Thyroid Surgery, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Kosei Maemura
- Department of Digestive Surgery, Breast and Thyroid Surgery, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Akihide Tanimoto
- Department of Molecular and Cellular Pathology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Shoji Natsugoe
- Department of Digestive Surgery, Breast and Thyroid Surgery, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
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23
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Xu Q, Wu N, Cui L, Wu Z, Qiu G. Filamin B: The next hotspot in skeletal research? J Genet Genomics 2017; 44:335-342. [PMID: 28739045 DOI: 10.1016/j.jgg.2017.04.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 03/15/2017] [Accepted: 04/12/2017] [Indexed: 12/19/2022]
Abstract
Filamin B (FLNB) is a large dimeric actin-binding protein which crosslinks actin cytoskeleton filaments into a dynamic structure. Up to present, pathogenic mutations in FLNB are solely found to cause skeletal deformities, indicating the important role of FLNB in skeletal development. FLNB-related disorders are classified as spondylocarpotarsal synostosis (SCT), Larsen syndrome (LS), atelosteogenesis (AO), boomerang dysplasia (BD), and isolated congenital talipes equinovarus, presenting with scoliosis, short-limbed dwarfism, clubfoot, joint dislocation and other unique skeletal abnormalities. Several mechanisms of FLNB mutations causing skeletal malformations have been proposed, including delay of ossification in long bone growth plate, reduction of bone mineral density (BMD), dysregulation of muscle differentiation, ossification of intervertebral disc (IVD), disturbance of proliferation, differentiation and apoptosis in chondrocytes, impairment of angiogenesis, and hypomotility of osteoblast, chondrocyte and fibroblast. Interventions on FLNB-related diseases require prenatal surveillance by sonography, gene testing in high-risk carriers, and proper orthosis or orthopedic surgeries to correct malformations including scoliosis, cervical spine instability, large joint dislocation, and clubfoot. Gene and cell therapies for FLNB-related diseases are also promising but require further studies.
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Affiliation(s)
- Qiming Xu
- Department of Orthopaedic Surgery, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Nan Wu
- Department of Orthopaedic Surgery, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China; Beijing Key Laboratory for Genetic Research of Skeletal Deformity, Beijing 100730, China; Medical Research Center of Orthopaedics, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Lijia Cui
- Peking Union Medical College Hospital, Beijing 100730, China; School of Medicine, Tsinghua University, Beijing 100084, China
| | - Zhihong Wu
- Beijing Key Laboratory for Genetic Research of Skeletal Deformity, Beijing 100730, China; Medical Research Center of Orthopaedics, Chinese Academy of Medical Sciences, Beijing 100730, China; Department of Central Laboratory, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Guixing Qiu
- Department of Orthopaedic Surgery, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China; Beijing Key Laboratory for Genetic Research of Skeletal Deformity, Beijing 100730, China; Medical Research Center of Orthopaedics, Chinese Academy of Medical Sciences, Beijing 100730, China.
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24
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Yang CF, Wang CH, Siong H'ng W, Chang CP, Lin WD, Chen YT, Wu JY, Tsai FJ. Filamin B Loss-of-Function Mutation in Dimerization Domain Causes Autosomal-Recessive Spondylocarpotarsal Synostosis Syndrome with Rib Anomalies. Hum Mutat 2017; 38:540-547. [PMID: 28145000 DOI: 10.1002/humu.23186] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 01/23/2017] [Indexed: 02/06/2023]
Abstract
Spondylocarpotarsal synostosis syndrome (SCT) is a distinct group of disorders characterized by short stature, disrupted vertebral segmentation with vertebral fusion, scoliosis, lordosis, carpal/tarsal synostosis, and lack of rib anomalies. Mutations in filamin B (FLNB) and MYH3 have been reported for autosomal-recessive and autosomal-dominant SCT, respectively. We present a family with two patients suffering from autosomal-recessive SCT with rib anomalies, including malalignment, crowding, and uneven size and shape of ribs. Whole-exome sequencing revealed a novel p.S2542Lfs* 82 (c.7621dup) frameshift mutation in FLNB. This frameshift mutation lies in the C-terminal-most domain involved in FLNB dimerization and resulted in a 20-residue elongation, with complete familial segregation and absence in 376 normal controls. The mutant p.S2542Lfs* 82 FLNB demonstrated a complete loss of ability to form a functional dimer in transiently transfected HEK293T cells. The p.S2542Lfs* 82 mutation also led to significantly reduced protein levels and accumulation of the mutant protein in the Golgi apparatus. This is the first identified mutation in the dimerization domain of FLNB. This loss-of-function frameshift mutation in FLNB causes autosomal-recessive SCT with rarely reported rib anomalies. This report demonstrates the involvement of rib anomaly in SCT and its causative mutation in the dimerization domain of FLNB.
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Affiliation(s)
- Chi-Fan Yang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Chung-Hsing Wang
- Department of Genetics and Metabolism, Children's Hospital of China Medical University, Taichung, Taiwan
- School of Medicine, China Medical University, Taichung, Taiwan
| | - Weng Siong H'ng
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Chun-Ping Chang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Wei-De Lin
- Department of Medical Genetics, China Medical University Hospital, Taichung, Taiwan
- School of Post Baccalaureate Chinese Medicine, China Medical University, Taichung, Taiwan
| | - Yuan-Tsong Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Jer-Yuarn Wu
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Fuu-Jen Tsai
- Department of Medical Genetics, China Medical University Hospital, Taichung, Taiwan
- Department of Medical Research, China Medical University Hospital, Taichung, Taiwan
- School of Chinese Medicine, China Medical University, Taichung, Taiwan
- Division of Pediatric Genetics, Endocrinology & Metabolism, China Medical University Children's Hospital, Taichung, Taiwan
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25
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Reimann L, Wiese H, Leber Y, Schwäble AN, Fricke AL, Rohland A, Knapp B, Peikert CD, Drepper F, van der Ven PFM, Radziwill G, Fürst DO, Warscheid B. Myofibrillar Z-discs Are a Protein Phosphorylation Hot Spot with Protein Kinase C (PKCα) Modulating Protein Dynamics. Mol Cell Proteomics 2016; 16:346-367. [PMID: 28028127 DOI: 10.1074/mcp.m116.065425] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Indexed: 11/06/2022] Open
Abstract
The Z-disc is a protein-rich structure critically important for the development and integrity of myofibrils, which are the contractile organelles of cross-striated muscle cells. We here used mouse C2C12 myoblast, which were differentiated into myotubes, followed by electrical pulse stimulation (EPS) to generate contracting myotubes comprising mature Z-discs. Using a quantitative proteomics approach, we found significant changes in the relative abundance of 387 proteins in myoblasts versus differentiated myotubes, reflecting the drastic phenotypic conversion of these cells during myogenesis. Interestingly, EPS of differentiated myotubes to induce Z-disc assembly and maturation resulted in increased levels of proteins involved in ATP synthesis, presumably to fulfill the higher energy demand of contracting myotubes. Because an important role of the Z-disc for signal integration and transduction was recently suggested, its precise phosphorylation landscape further warranted in-depth analysis. We therefore established, by global phosphoproteomics of EPS-treated contracting myotubes, a comprehensive site-resolved protein phosphorylation map of the Z-disc and found that it is a phosphorylation hotspot in skeletal myocytes, underscoring its functions in signaling and disease-related processes. In an illustrative fashion, we analyzed the actin-binding multiadaptor protein filamin C (FLNc), which is essential for Z-disc assembly and maintenance, and found that PKCα phosphorylation at distinct serine residues in its hinge 2 region prevents its cleavage at an adjacent tyrosine residue by calpain 1. Fluorescence recovery after photobleaching experiments indicated that this phosphorylation modulates FLNc dynamics. Moreover, FLNc lacking the cleaved Ig-like domain 24 exhibited remarkably fast kinetics and exceedingly high mobility. Our data set provides research community resource for further identification of kinase-mediated changes in myofibrillar protein interactions, kinetics, and mobility that will greatly advance our understanding of Z-disc dynamics and signaling.
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Affiliation(s)
- Lena Reimann
- From the ‡Department of Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Heike Wiese
- From the ‡Department of Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Yvonne Leber
- ¶Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, 53121 Bonn, Germany
| | - Anja N Schwäble
- From the ‡Department of Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Anna L Fricke
- From the ‡Department of Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Anne Rohland
- ¶Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, 53121 Bonn, Germany
| | - Bettina Knapp
- From the ‡Department of Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Christian D Peikert
- From the ‡Department of Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Friedel Drepper
- From the ‡Department of Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Peter F M van der Ven
- ¶Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, 53121 Bonn, Germany
| | - Gerald Radziwill
- From the ‡Department of Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany.,§BIOSS Centre for Biological Signalling Studies, University of Freiburg
| | - Dieter O Fürst
- ¶Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, 53121 Bonn, Germany
| | - Bettina Warscheid
- From the ‡Department of Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany; .,§BIOSS Centre for Biological Signalling Studies, University of Freiburg
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26
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Tsui JCC, Lau CPY, Cheung AC, Wong KC, Huang L, Tsui SKW, Kumta SM. Differential expression of filamin B splice variants in giant cell tumor cells. Oncol Rep 2016; 36:3181-3187. [PMID: 27779699 PMCID: PMC5112600 DOI: 10.3892/or.2016.5197] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 10/18/2016] [Indexed: 12/27/2022] Open
Abstract
Giant cell tumor of bone (GCT) is the most commonly reported non-malignant bone tumor in Hong Kong. This kind of tumor usually affects people aged 20–40 years. Also, it is well known for recurrence locally, especially when the tumor cannot be removed completely. Filamins are actin-binding proteins which contain three family members, filamin A, B and C. They are the products of three different genes, FLNA, FLNB and FLNC, which can generate various transcript variants in different cell types. In this study, we focused on the effects of FLNBv2 and FLNBv4 toward GCT cells. The only difference between FLNBv2 and FLNBv4 is that FLNBv4 does not contain hinge 1 region. We found that the relative abundance of FLNBv4 varies among different GCT cell lines while the expression level of FLNBv4 in normal osteoblasts was only marginally detectable. In the functional aspect, overexpression of FLNBv4 led to upregulation of RANKL, OCN, OPG and RUNX2, which are closely related to GCT cell survival and differentiation. Moreover, FLNBv4 can have a negative effect on cell viability of GCT cells when compare with FLNBv2. In conclusion, splicing variants of FLNB are differentially expressed in GCT cells and may play a role in the proliferation and differentiation of tumor cells.
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Affiliation(s)
- Joseph Chi-Ching Tsui
- Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Shatin, Hong Kong, SAR, P.R. China
| | - Carol Po-Ying Lau
- Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Shatin, Hong Kong, SAR, P.R. China
| | - Alex Chun Cheung
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, SAR, P.R. China
| | - Kwok-Chuen Wong
- Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Shatin, Hong Kong, SAR, P.R. China
| | - Lin Huang
- Department of Surgery, The Chinese University of Hong Kong, Shatin, Hong Kong, SAR, P.R. China
| | - Stephen Kwok-Wing Tsui
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, SAR, P.R. China
| | - Shekhar Madhukar Kumta
- Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Shatin, Hong Kong, SAR, P.R. China
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27
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Khavari A, Nydén M, Weitz DA, Ehrlicher AJ. Composite alginate gels for tunable cellular microenvironment mechanics. Sci Rep 2016; 6:30854. [PMID: 27484403 PMCID: PMC4971458 DOI: 10.1038/srep30854] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 07/08/2016] [Indexed: 01/06/2023] Open
Abstract
The mechanics of the cellular microenvironment can be as critical as biochemistry in directing cell behavior. Many commonly utilized materials derived from extra-cellular-matrix create excellent scaffolds for cell growth, however, evaluating the relative mechanical and biochemical effects independently in 3D environments has been difficult in frequently used biopolymer matrices. Here we present 3D sodium alginate hydrogel microenvironments over a physiological range of stiffness (E = 1.85 to 5.29 kPa), with and without RGD binding sites or collagen fibers. We use confocal microscopy to measure the growth of multi-cellular aggregates (MCAs), of increasing metastatic potential in different elastic moduli of hydrogels, with and without binding factors. We find that the hydrogel stiffness regulates the growth and morphology of these cell clusters; MCAs grow larger and faster in the more rigid environments similar to cancerous breast tissue (E = 4–12 kPa) as compared to healthy tissue (E = 0.4–2 kpa). Adding binding factors from collagen and RGD peptides increases growth rates, and change maximum MCA sizes. These findings demonstrate the utility of these independently tunable mechanical/biochemistry gels, and that mechanical confinement in stiffer microenvironments may increase cell proliferation.
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Affiliation(s)
- Adele Khavari
- Applied Chemistry, Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.,SUMO Biomaterials VINN Excellence Center, Chalmers University of Technology, SE-412 96 Göteborg, Sweden
| | - Magnus Nydén
- Applied Chemistry, Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.,UCL Australia, 220 Victoria Square, Adelaide, SA 5000 Australia
| | - David A Weitz
- Department of Bioengineering, McGill University, Montreal Canada H3A 0C3
| | - Allen J Ehrlicher
- Department of Bioengineering, McGill University, Montreal Canada H3A 0C3.,School of Engineering and Applied Sciences, Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.,Beth Israel Deaconess Medical Center, Boston, Massachusetts 02115, United States.,Harvard Medical School, Boston, Massachusetts 02115, United States
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28
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Leber Y, Ruparelia AA, Kirfel G, van der Ven PFM, Hoffmann B, Merkel R, Bryson-Richardson RJ, Fürst DO. Filamin C is a highly dynamic protein associated with fast repair of myofibrillar microdamage. Hum Mol Genet 2016; 25:2776-2788. [PMID: 27206985 DOI: 10.1093/hmg/ddw135] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 04/26/2016] [Accepted: 04/27/2016] [Indexed: 11/12/2022] Open
Abstract
Filamin c (FLNc) is a large dimeric actin-binding protein located at premyofibrils, myofibrillar Z-discs and myofibrillar attachment sites of striated muscle cells, where it is involved in mechanical stabilization, mechanosensation and intracellular signaling. Mutations in the gene encoding FLNc give rise to skeletal muscle diseases and cardiomyopathies. Here, we demonstrate by fluorescence recovery after photobleaching that a large fraction of FLNc is highly mobile in cultured neonatal mouse cardiomyocytes and in cardiac and skeletal muscles of live transgenic zebrafish embryos. Analysis of cardiomyocytes from Xirp1 and Xirp2 deficient animals indicates that both Xin actin-binding repeat-containing proteins stabilize FLNc selectively in premyofibrils. Using a novel assay to analyze myofibrillar microdamage and subsequent repair in cultured contracting cardiomyocytes by live cell imaging, we demonstrate that repair of damaged myofibrils is achieved within only 4 h, even in the absence of de novo protein synthesis. FLNc is immediately recruited to these sarcomeric lesions together with its binding partner aciculin and precedes detectable assembly of filamentous actin and recruitment of other myofibrillar proteins. These data disclose an unprecedented degree of flexibility of the almost crystalline contractile machinery and imply FLNc as a dynamic signaling hub, rather than a primarily structural protein. Our myofibrillar damage/repair model illustrates how (cardio)myocytes are kept functional in their mechanically and metabolically strained environment. Our results help to better understand the pathomechanisms and pathophysiology of early stages of FLNc-related myofibrillar myopathy and skeletal and cardiac diseases preceding pathological protein aggregation.
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Affiliation(s)
- Yvonne Leber
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, D53121 Bonn, Germany
| | - Avnika A Ruparelia
- School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia
| | - Gregor Kirfel
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, D53121 Bonn, Germany
| | - Peter F M van der Ven
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, D53121 Bonn, Germany
| | - Bernd Hoffmann
- Department of Biomechanics (ICS-7), Institute of Complex Systems, Forschungszentrum Jülich, D52428 Jülich, Germany and
| | - Rudolf Merkel
- Department of Biomechanics (ICS-7), Institute of Complex Systems, Forschungszentrum Jülich, D52428 Jülich, Germany and.,Department of Biomechanics, Institute for Physical and Theoretical Chemistry, University of Bonn, D53115 Bonn, Germany
| | | | - Dieter O Fürst
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, D53121 Bonn, Germany
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29
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Zhao M, Li H, Liu X, Wei J, Ji J, Yang S, Hu Z, Wei S. Response of Human Osteoblast to n-HA/PEEK--Quantitative Proteomic Study of Bio-effects of Nano-Hydroxyapatite Composite. Sci Rep 2016; 6:22832. [PMID: 26956660 PMCID: PMC4783780 DOI: 10.1038/srep22832] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 02/22/2016] [Indexed: 01/27/2023] Open
Abstract
Nano-sized hydroxyapatite (n-HA) is considered as a bio-active material, which is often mixed into bone implant material, polyetheretherketone (PEEK). To reveal the global protein expression modulations of osteoblast in response to direct contact with the PEEK composite containing high level (40%) nano-sized hydroxyapatite (n-HA/PEEK) and explain its comprehensive bio-effects, quantitative proteomic analysis was conducted on human osteoblast-like cells MG-63 cultured on n-HA/PEEK in comparison with pure PEEK. Results from quantitative proteomic analysis showed that the most enriched categories in the up-regulated proteins were related to calcium ion processes and associated functions while the most enriched categories in the down-regulated proteins were related to RNA process. This enhanced our understanding to the molecular mechanism of the promotion of the cell adhesion and differentiation with the inhibition of the cell proliferation on n-HA/PEEK composite. It also exhibited that although the calcium ion level of incubate environment hadn't increased, merely the calcium fixed on the surface of material had influence to intracellular calcium related processes, which was also reflect by the higher intracellular Ca(2+) concentration of n-HA/PEEK. This study could lead to more comprehensive cognition to the versatile biocompatibility of composite materials. It further proves that proteomics is useful in new bio-effect discovery.
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Affiliation(s)
- Minzhi Zhao
- CAS Key Laboratory for Biomedical Effects of Nanomaterials & Nanosafety, National Center for Nanoscience and Technology, Chinese Academy of Sciences, Beijing 100190, China
| | - Haiyun Li
- CAS Key Laboratory for Biomedical Effects of Nanomaterials & Nanosafety, National Center for Nanoscience and Technology, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiaochen Liu
- Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, 100871, Beijing, China
| | - Jie Wei
- Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237, China
| | - Jianguo Ji
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China
| | - Shu Yang
- CAS Key Laboratory for Biomedical Effects of Nanomaterials & Nanosafety, National Center for Nanoscience and Technology, Chinese Academy of Sciences, Beijing 100190, China
| | - Zhiyuan Hu
- CAS Key Laboratory for Biomedical Effects of Nanomaterials & Nanosafety, National Center for Nanoscience and Technology, Chinese Academy of Sciences, Beijing 100190, China
| | - Shicheng Wei
- Center for Craniofacial Stem Cell Research and Regeneration, Department of Orthodontics, Laboratory of Interdisciplinary Studies, Peking University School and Hospital of Stomatology, Beijing 100081, China
- Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, 100871, Beijing, China
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30
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Dotson D, Woodruff EA, Villalta F, Dong X. Filamin A Is Involved in HIV-1 Vpu-mediated Evasion of Host Restriction by Modulating Tetherin Expression. J Biol Chem 2016; 291:4236-46. [PMID: 26742839 DOI: 10.1074/jbc.m115.708123] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Indexed: 11/06/2022] Open
Abstract
Tetherin, also known as bone marrow stromal antigen 2 (BST-2), inhibits the release of a wide range of enveloped viruses, including human immunodeficiency virus, type 1 (HIV-1) by directly tethering nascent virions to the surface of infected cells. The HIV-1 accessary protein Vpu counteracts tetherin restriction via sequestration, down-regulation, and/or displacement mechanisms to remove tetherin from sites of virus budding. However, the exact mechanism of Vpu-mediated antagonism of tetherin restriction remains to be fully understood. Here we report a novel role for the actin cross-linking regulator filamin A (FLNa) in Vpu anti-tetherin activities. We demonstrate that FLNa associates with tetherin and that FLNa modulates tetherin turnover. FLNa deficiency was found to enhance cell surface and steady-state levels of tetherin expression. In contrast, we observed that overexpression of FLNa reduced tetherin expression levels both on the plasma membrane and in intracellular compartments. Although FLNb shows high amino acid sequence similarity with FLNa, we reveal that only FLNa, but not FLNb, plays an essential role in tetherin turnover. We further showed that FLNa deficiency inhibited Vpu-mediated enhancement of virus release through interfering with the activity of Vpu to down-regulate cellular tetherin. Taken together, our studies suggest that Vpu hijacks the FLNa function in the modulation of tetherin to neutralize the antiviral factor tetherin. These findings may provide novel strategies for the treatment of HIV-1 infection.
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Affiliation(s)
- Dominique Dotson
- From the Department of Microbiology and Immunology and Center for AIDS Health Disparities Research, School of Medicine, Meharry Medical College, Nashville, Tennessee 37208
| | - Elvin A Woodruff
- From the Department of Microbiology and Immunology and Center for AIDS Health Disparities Research, School of Medicine, Meharry Medical College, Nashville, Tennessee 37208
| | - Fernando Villalta
- From the Department of Microbiology and Immunology and Center for AIDS Health Disparities Research, School of Medicine, Meharry Medical College, Nashville, Tennessee 37208
| | - Xinhong Dong
- From the Department of Microbiology and Immunology and Center for AIDS Health Disparities Research, School of Medicine, Meharry Medical College, Nashville, Tennessee 37208
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31
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Song M, He Q, Berk BA, Hartwig JH, Stossel TP, Nakamura F. An adventitious interaction of filamin A with RhoGDI2(Tyr153Glu). Biochem Biophys Res Commun 2015; 469:659-64. [PMID: 26707877 DOI: 10.1016/j.bbrc.2015.12.044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 12/11/2015] [Indexed: 01/12/2023]
Abstract
Filamin A (FLNA) is an actin filament crosslinking protein with multiple intracellular binding partners. Mechanical force exposes cryptic FLNA binding sites for some of these ligands. To identify new force-dependent binding interactions, we used a fusion construct composed of two FLNA domains, one of which was previously identified as containing a force-dependent binding site as a bait in a yeast two-hybrid system and identified the Rho dissociation inhibitor 2 (RhoGDI2) as a potential interacting partner. A RhoGDI2 truncate with 81 N-terminal amino acid residues and a phosphomimetic mutant, RhoGDI(Tyr153Glu) interacted with the FLNA construct. However, neither wild-type or full-length RhoGDI2 phosphorylated at Y153 interacted with FLNA. Our interpretation of these contradictions is that truncation and/or mutation of RhoGDI2 perturbs its conformation to expose a site that adventitiously binds FLNA and is not a bona-fide interaction. Therefore, previous studies reporting that a RhoGDI(Y153E) mutant suppresses the metastasis of human bladder cancer cells must be reinvestigated in light of artificial interaction of this point mutant with FLNA.
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Affiliation(s)
- Mia Song
- Hematology Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston MA, USA
| | - Qianjing He
- Hematology Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston MA, USA
| | - Benjamin-Andreas Berk
- Faculty of Veterinary Medicine and Faculty of Biosciences and Pharmacy, University of Leipzig, Leipzig, Germany
| | - John H Hartwig
- Hematology Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston MA, USA
| | - Thomas P Stossel
- Hematology Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston MA, USA
| | - Fumihiko Nakamura
- Hematology Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston MA, USA.
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32
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Tirupula KC, Ithychanda SS, Mohan ML, Naga Prasad SV, Qin J, Karnik SS. G protein-coupled receptors directly bind filamin A with high affinity and promote filamin phosphorylation. Biochemistry 2015; 54:6673-83. [PMID: 26460884 PMCID: PMC4642222 DOI: 10.1021/acs.biochem.5b00975] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Although interaction of a few G protein-coupled receptors (GPCRs) with Filamin A, a key actin cross-linking and biomechanical signal transducer protein, has been observed, a comprehensive structure-function analysis of this interaction is lacking. Through a systematic sequence-based analysis, we found that a conserved filamin binding motif is present in the cytoplasmic domains of >20% of the 824 GPCRs encoded in the human genome. Direct high-affinity interaction of filamin binding motif peptides of select GPCRs with the Ig domain of Filamin A was confirmed by nuclear magnetic resonance spectroscopy and isothermal titration calorimetric experiments. Engagement of the filamin binding motif with the Filamin A Ig domain induced the phosphorylation of filamin by protein kinase A in vitro. In transfected cells, agonist activation as well as constitutive activation of representative GPCRs dramatically elicited recruitment and phosphorylation of cellular Filamin A, a phenomenon long known to be crucial for regulating the structure and dynamics of the cytoskeleton. Our data suggest a molecular mechanism for direct GPCR-cytoskeleton coupling via filamin. Until now, GPCR signaling to the cytoskeleton was predominantly thought to be indirect, through canonical G protein-mediated signaling cascades involving GTPases, adenylyl cyclases, phospholipases, ion channels, and protein kinases. We propose that the GPCR-induced filamin phosphorylation pathway is a conserved, novel biochemical signaling paradigm.
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Affiliation(s)
- Kalyan C Tirupula
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic , Cleveland, Ohio 44195, United States
| | - Sujay S Ithychanda
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic , Cleveland, Ohio 44195, United States
| | - Maradumane L Mohan
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic , Cleveland, Ohio 44195, United States
| | - Sathyamangla V Naga Prasad
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic , Cleveland, Ohio 44195, United States
| | - Jun Qin
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic , Cleveland, Ohio 44195, United States
| | - Sadashiva S Karnik
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic , Cleveland, Ohio 44195, United States
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33
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Zhao Y, Shapiro SS, Eto M. F-actin clustering and cell dysmotility induced by the pathological W148R missense mutation of filamin B at the actin-binding domain. Am J Physiol Cell Physiol 2015; 310:C89-98. [PMID: 26491051 DOI: 10.1152/ajpcell.00274.2015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 10/19/2015] [Indexed: 11/22/2022]
Abstract
Filamin B (FLNB) is a dimeric actin-binding protein that orchestrates the reorganization of the actin cytoskeleton. Congenital mutations of FLNB at the actin-binding domain (ABD) are known to cause abnormalities of skeletal development, such as atelosteogenesis types I and III and Larsen's syndrome, although the underlying mechanisms are poorly understood. Here, using fluorescence microscopy, we characterized the reorganization of the actin cytoskeleton in cells expressing each of six pathological FLNB mutants that have been linked to skeletal abnormalities. The subfractionation assay showed a greater accumulation of the FLNB ABD mutants W148R and E227K than the wild-type protein to the cytoskeleton. Ectopic expression of FLNB-W148R and, to a lesser extent, FLNB-E227K induced prominent F-actin accumulations and the consequent rearrangement of focal adhesions, myosin II, and septin filaments and results in a delayed directional migration of the cells. The W148R protein-induced cytoskeletal rearrangement was partially attenuated by the inhibition of myosin II, p21-activated protein kinase, or Rho-associated protein kinase. The expression of a single-head ABD fragment with the mutations partially mimicked the rearrangement induced by the dimer. The F-actin clustering through the interaction with the mutant FLNB ABD may limit the cytoskeletal reorganization, preventing normal skeletal development.
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Affiliation(s)
- Yongtong Zhao
- Department of Molecular Physiology and Biophysics, Sidney Kimmel Medical College at Thomas Jefferson University, and Sidney Kimmel Cancer Center, Philadelphia, Pennsylvania
| | - Sandor S Shapiro
- Department of Molecular Physiology and Biophysics, Sidney Kimmel Medical College at Thomas Jefferson University, and Sidney Kimmel Cancer Center, Philadelphia, Pennsylvania
| | - Masumi Eto
- Department of Molecular Physiology and Biophysics, Sidney Kimmel Medical College at Thomas Jefferson University, and Sidney Kimmel Cancer Center, Philadelphia, Pennsylvania
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Exon skipping causes atypical phenotypes associated with a loss-of-function mutation in FLNA by restoring its protein function. Eur J Hum Genet 2015; 24:408-14. [PMID: 26059841 DOI: 10.1038/ejhg.2015.119] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 04/22/2015] [Accepted: 04/27/2015] [Indexed: 11/09/2022] Open
Abstract
Loss-of-function mutations in filamin A (FLNA) cause an X-linked dominant disorder with multiple organ involvement. Affected females present with periventricular nodular heterotopia (PVNH), cardiovascular complications, thrombocytopenia and Ehlers-Danlos syndrome. These mutations are typically lethal to males, and rare male survivors suffer from failure to thrive, PVNH, and severe cardiovascular and gastrointestinal complications. Here we report two surviving male siblings with a loss-of-function mutation in FLNA. They presented with multiple complications, including valvulopathy, intestinal malrotation and chronic intestinal pseudo-obstruction (CIPO). However, these siblings had atypical clinical courses, such as a lack of PVNH and a spontaneous improvement of CIPO. Trio-based whole-exome sequencing revealed a 4-bp deletion in exon 40 that was predicted to cause a lethal premature protein truncation. However, molecular investigations revealed that the mutation induced in-frame skipping of the mutated exon, which led to the translation of a mutant FLNA missing an internal region of 41 amino acids. Functional analyses of the mutant protein suggested that its binding affinity to integrin, as well as its capacity to induce focal adhesions, were comparable to those of the wild-type protein. These results suggested that exon skipping of FLNA partially restored its protein function, which could contribute to amelioration of the siblings' clinical courses. This study expands the diversity of the phenotypes associated with loss-of-function mutations in FLNA.
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35
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Razinia Z, Baldassarre M, Cantelli G, Calderwood DA. ASB2α, an E3 ubiquitin ligase specificity subunit, regulates cell spreading and triggers proteasomal degradation of filamins by targeting the filamin calponin homology 1 domain. J Biol Chem 2013; 288:32093-105. [PMID: 24052262 DOI: 10.1074/jbc.m113.496604] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Filamins are actin-binding and cross-linking proteins that organize the actin cytoskeleton and anchor transmembrane proteins to the cytoskeleton and scaffold signaling pathways. During hematopoietic cell differentiation, transient expression of ASB2α, the specificity subunit of an E3-ubiquitin ligase complex, triggers acute proteasomal degradation of filamins. This led to the proposal that ASB2α regulates hematopoietic cell differentiation by modulating cell adhesion, spreading, and actin remodeling through targeted degradation of filamins. Here, we show that the calponin homology domain 1 (CH1), within the filamin A (FLNa) actin-binding domain, is the minimal fragment sufficient for ASB2α-mediated degradation. Combining an in-depth flow cytometry analysis with mutagenesis of lysine residues within CH1, we find that arginine substitution at each of a cluster of three lysines (Lys-42, Lys-43, and Lys-135) renders FLNa resistant to ASB2α-mediated degradation without altering ASB2α binding. These lysines lie within previously predicted actin-binding sites, and the ASB2α-resistant filamin mutant is defective in targeting to F-actin-rich structures in cells. However, by swapping CH1 with that of α-actinin1, which is resistant to ASB2α-mediated degradation, we generated an ASB2α-resistant chimeric FLNa with normal subcellular localization. Notably, this chimera fully rescues the impaired cell spreading induced by ASB2α expression. Our data therefore reveal ubiquitin acceptor sites in FLNa and establish that ASB2α-mediated effects on cell spreading are due to loss of filamins.
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36
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Feng HZ, Wang Q, Reiter RS, Lin JLC, Lin JJC, Jin JP. Localization and function of Xinα in mouse skeletal muscle. Am J Physiol Cell Physiol 2013; 304:C1002-12. [PMID: 23485711 DOI: 10.1152/ajpcell.00005.2013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The Xin repeat-containing proteins were originally found in the intercalated discs of cardiac muscle with implicated roles in cardiac development and function. A pair of paralogous genes, Xinα (Xirp1) and Xinβ (Xirp2), is present in mammals. Ablation of the mouse Xinα (mXinα) did not affect heart development but caused late-onset adulthood cardiac hypertrophy and cardiomyopathy with conductive defects. Both mXinα and mXinβ are also found in the myotendinous junction (MTJ) of skeletal muscle. Here we investigated the structural and functional significance of mXinα in skeletal muscle. In addition to MTJ and the contact sites between muscle and perimysium, mXinα but not mXinβ was found in the blood vessel walls, whereas both proteins were absent in neuromuscular junctions and nerve fascicles. Coimmunoprecipitation suggested association of mXinα with talin, vinculin, and filamin, but not β-catenin, in adult skeletal muscle, consistent with our previous report of colocalization of mXinα with vinculin. Loss of mXinα in mXinα-null mice had subtle effects on the MTJ structure and the levels of several MTJ components. Diaphragm muscle of mXinα-null mice showed hypertrophy. Compared with wild-type controls, mouse extensor digitorum longus (EDL) muscle lacking mXinα exhibited no overt change in contractile and relaxation velocities or maximum force development but better tolerance to fatigue. Loaded fatigue contractions generated stretch injury in wild-type EDL muscle as indicated by a fragmentation of troponin T. This effect was blunted in mXinα-null EDL muscle. The results suggest that mXinα play a role in MTJ conductance of contractile and stretching forces.
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Affiliation(s)
- Han-Zhong Feng
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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37
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Fujimoto D, Hirono Y, Goi T, Katayama K, Matsukawa S, Yamaguchi A. The activation of proteinase-activated receptor-1 (PAR1) promotes gastric cancer cell alteration of cellular morphology related to cell motility and invasion. Int J Oncol 2012; 42:565-73. [PMID: 23242308 DOI: 10.3892/ijo.2012.1738] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 11/23/2012] [Indexed: 12/11/2022] Open
Abstract
Cell motility proceeds by cycles of edge protrusion, adhesion and retraction. Whether these functions are coordinated by biochemical or biomechanical processes is unknown. Tumor invasion and metastasis is directly related to cell motility. We showed that stimulation of proteinase-activated receptor-1 (PAR1) can trigger an array of responses that would promote tumor cell growth and invasion. Thus, we examined aspects of PAR1 activation related to cell morphological change that might contribute to cell motility. We established a PAR1 stably transfected MKN45 gastric cancer cell line (MKN45/PAR1). We examined morphological changes, Rho family activation and overexpression of cytoskeletal protein in cells exposed to PAR1 agonists (α-thrombin and TFLLR-NH2). MKN45/PAR1 grows with an elongated and polarized morphology, extending pseudopodia at the leading edge. However, in the presence of PAR1 antagonist, MKN45/PAR1 did not show any changes in cell shape upon addition of either α-thrombin or TFLLR-NH2. Activated PAR1 induced RhoA and Rac1 phosphorylation, and subsequent overexpression of myosin IIA and filamin B which are stress fiber components that were identified by PMF analysis of peptide mass data obtained by MALDI-TOF/MS measurement. Upon stimulation of MKN45/PAR1 for 24 h with either α-thrombin or TFLLR-NH2, the distribution of both myosin IIA and filamin B proteins shifted to being distributed throughout the cytoplasm to the membrane, with more intense luminescence signals than in the absence of stimulation. These results demonstrate that PAR1 activation induces cell morphological change associated with cell motility via Rho family activation and cytoskeletal protein overexpression, and has a critical role in gastric cancer cell invasion and metastasis.
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Affiliation(s)
- Daisuke Fujimoto
- First Department of Surgery, Faculty of Medicine and Division of Bioresearch Laboratories, University of Fukui, Fukui 910-1193, Japan
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38
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Filamin isoforms in molluscan smooth muscle. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2012; 1824:1334-41. [DOI: 10.1016/j.bbapap.2012.07.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 06/28/2012] [Accepted: 07/23/2012] [Indexed: 11/23/2022]
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Warzecha CC, Carstens RP. Complex changes in alternative pre-mRNA splicing play a central role in the epithelial-to-mesenchymal transition (EMT). Semin Cancer Biol 2012; 22:417-27. [PMID: 22548723 DOI: 10.1016/j.semcancer.2012.04.003] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Accepted: 04/16/2012] [Indexed: 12/18/2022]
Abstract
The epithelial-to-mesenchymal transition (EMT) is an important developmental process that is also implicated in disease pathophysiology, such as cancer progression and metastasis. A wealth of literature in recent years has identified important transcriptional regulators and large-scale changes in gene expression programs that drive the phenotypic changes that occur during the EMT. However, in the past couple of years it has become apparent that extensive changes in alternative splicing also play a profound role in shaping the changes in cell behavior that characterize the EMT. While long known splicing switches in FGFR2 and p120-catenin provided hints of a larger program of EMT-associated alternative splicing, the recent identification of the epithelial splicing regulatory proteins 1 and 2 (ESRP1 and ESRP2) began to reveal this genome-wide post-transcriptional network. Several studies have now demonstrated the truly vast extent of this alternative splicing program. The global switches in splicing associated with the EMT add an important additional layer of post-transcriptional control that works in harmony with transcriptional and epigenetic regulation to effect complex changes in cell shape, polarity, and behavior that mediate transitions between epithelial and mesenchymal cell states. Future challenges include the need to investigate the functional consequences of these splicing switches at both the individual gene as well as systems level.
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Affiliation(s)
- Claude C Warzecha
- Department of Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104, United States
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40
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Abstract
Filamins are essential, evolutionarily conserved, modular, multidomain, actin-binding proteins that organize the actin cytoskeleton and maintain extracellular matrix connections by anchoring actin filaments to transmembrane receptors. By cross-linking and anchoring actin filaments, filamins stabilize the plasma membrane, provide cellular cortical rigidity, and contribute to the mechanical stability of the plasma membrane and the cell cortex. In addition to binding actin, filamins interact with more than 90 other binding partners including intracellular signaling molecules, receptors, ion channels, transcription factors, and cytoskeletal and adhesion proteins. Thus, filamins scaffold a wide range of signaling pathways and are implicated in the regulation of a diverse array of cellular functions including motility, maintenance of cell shape, and differentiation. Here, we review emerging structural and functional evidence that filamins are mechanosensors and/or mechanotransducers playing essential roles in helping cells detect and respond to physical forces in their local environment.
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Affiliation(s)
- Ziba Razinia
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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41
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Daniel PB, Morgan T, Alanay Y, Bijlsma E, Cho TJ, Cole T, Collins F, David A, Devriendt K, Faivre L, Ikegawa S, Jacquemont S, Jesic M, Krakow D, Liebrecht D, Maitz S, Marlin S, Morin G, Nishikubo T, Nishimura G, Prescott T, Scarano G, Shafeghati Y, Skovby F, Tsutsumi S, Whiteford M, Zenker M, Robertson SP. Disease-associated mutations in the actin-binding domain of filamin B cause cytoplasmic focal accumulations correlating with disease severity. Hum Mutat 2012; 33:665-73. [DOI: 10.1002/humu.22012] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Accepted: 12/12/2011] [Indexed: 11/07/2022]
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42
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Ehrlicher AJ, Nakamura F, Hartwig JH, Weitz DA, Stossel TP. Mechanical strain in actin networks regulates FilGAP and integrin binding to filamin A. Nature 2011; 478:260-3. [PMID: 21926999 PMCID: PMC3204864 DOI: 10.1038/nature10430] [Citation(s) in RCA: 271] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 08/05/2011] [Indexed: 12/14/2022]
Affiliation(s)
- A J Ehrlicher
- Translational Medicine Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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43
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Razinia Z, Baldassarre M, Bouaouina M, Lamsoul I, Lutz PG, Calderwood DA. The E3 ubiquitin ligase specificity subunit ASB2α targets filamins for proteasomal degradation by interacting with the filamin actin-binding domain. J Cell Sci 2011; 124:2631-41. [PMID: 21750192 DOI: 10.1242/jcs.084343] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Filamins are an important family of actin-binding and crosslinking proteins that mediate remodeling of the actin cytoskeleton and maintain extracellular matrix connections by anchoring transmembrane proteins to actin filaments and linking them to intracellular signaling cascades. We recently found that filamins are targeted for proteasomal degradation by the E3 ubiquitin ligase specificity subunit ASBα and that acute degradation of filamins through this ubiquitin-proteasome pathway correlates with cell differentiation. Specifically, in myeloid leukemia cells retinoic-acid-induced expression of ASB2α triggers filamin degradation and recapitulates early events crucial for cell differentiation. ASB2α is thought to link substrates to the ubiquitin transferase machinery; however, the mechanism by which ASB2α interacts with filamin to induce degradation remained unknown. Here, we use cell-based and biochemical assays to show that the subcellular localization of ASB2α to actin-rich structures is dependent on filamin and that the actin-binding domain (ABD) of filamin mediates the interaction with ASB2α. Furthermore, we show that the ABD is necessary and sufficient for ASB2α-mediated filamin degradation. We propose that ASB2α exerts its effect by binding the ABD and mediating its polyubiquitylation, so targeting filamins for degradation. These studies provide the molecular basis for ASB2α-mediated filamin degradation and unravel an important mechanism by which filamin levels can be acutely regulated.
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Affiliation(s)
- Ziba Razinia
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520-8066, USA
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44
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Pentikäinen U, Jiang P, Takala H, Ruskamo S, Campbell ID, Ylänne J. Assembly of a filamin four-domain fragment and the influence of splicing variant-1 on the structure. J Biol Chem 2011; 286:26921-30. [PMID: 21636571 DOI: 10.1074/jbc.m110.195958] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Filamins are scaffold proteins that bind to various proteins, including the actin cytoskeleton, integrin adhesion receptors, and adaptor proteins such as migfilin. Alternative splicing of filamin, largely constructed from 24 Ig-like domains, is thought to have a role in regulating its interactions with other proteins. The filamin A splice variant-1 (FLNa var-1) lacks 41 amino acids, including the last β-strand of domain 19, FLNa(19), and the first β-strand of FLNa(20) that was previously shown to mask a key binding site on FLNa(21). Here, we present a structural characterization of domains 18-21, FLNa(18-21), in the FLNa var-1 as well as its nonspliced counterpart. A model of nonspliced FLNa(18-21), obtained from small angle x-ray scattering data, shows that these four domains form an L-shaped structure, with one arm composed of a pair of domains. NMR spectroscopy reveals that in the splice variant, FLNa(19) is unstructured whereas the other domains retain the same fold as in their canonical counterparts. The maximum dimensions predicted by small angle x-ray scattering data are increased upon migfilin binding in the FLNa(18-21) but not in the splice variant, suggesting that migfilin binding is able to displace the masking β-strand and cause a rearrangement of the structure. Possible function roles for the spliced variants are discussed.
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Affiliation(s)
- Ulla Pentikäinen
- Department of Biological and Environmental Science and Nanoscience Center, P. O. Box 35, University of Jyväskylä, Jyväskylä FI-40014, Finland.
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Ithychanda SS, Qin J. Evidence for multisite ligand binding and stretching of filamin by integrin and migfilin. Biochemistry 2011; 50:4229-31. [PMID: 21524097 PMCID: PMC3097901 DOI: 10.1021/bi2003229] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Filamin, a large cytoskeletal adaptor, connects plasma membrane to cytoskeleton by binding to transmembrane receptor integrin and actin. Seven of 24 filamin immunoglobulin repeats have conserved integrin binding sites, of which repeats 19 and 21 were shown to be autoinhibited by their adjacent repeats 18 and 20, respectively. Here we show using nuclear magnetic resonance spectroscopy that the autoinhibition can be relieved by integrin or integrin regulator migfilin. We further demonstrate that repeats 19 and 21 can simultaneously engage ligands. The data suggest that filamin is mechanically stretched by integrin or migfilin via a multisite binding mechanism for regulating cytoskeleton and integrin-mediated cell adhesion.
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Affiliation(s)
- Sujay Subbayya Ithychanda
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA
| | - Jun Qin
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA
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Pietsch J, Sickmann A, Weber G, Bauer J, Egli M, Wildgruber R, Infanger M, Grimm D. A proteomic approach to analysing spheroid formation of two human thyroid cell lines cultured on a random positioning machine. Proteomics 2011; 11:2095-104. [PMID: 21520503 DOI: 10.1002/pmic.201000817] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 01/26/2011] [Accepted: 02/17/2011] [Indexed: 01/17/2023]
Abstract
The human cell lines FTC-133 and CGTH W-1, both derived from patients with thyroid cancer, assemble to form different types of spheroids when cultured on a random positioning machine. In order to obtain a possible explanation for their distinguishable aggregation behaviour under equal culturing conditions, we evaluated a proteomic analysis emphasising cytoskeletal and membrane-associated proteins. For this analysis, we treated the cells by ultrasound, which freed up some of the proteins into the supernatant but left some attached to the cell fragments. Both types of proteins were further separated by free-flow IEF and SDS gel electrophoresis until their identity was determined by MS. The MS data revealed differences between the two cell lines with regard to various structural proteins such as vimentin, tubulins and actin. Interestingly, integrin α-5 chains, myosin-10 and filamin B were only found in FTC-133 cells, while collagen was only detected in CGTH W-1 cells. These analyses suggest that FTC-133 cells express surface proteins that bind fibronectin, strengthening the three-dimensional cell cohesion.
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Affiliation(s)
- Jessica Pietsch
- Department of Biology, Chemistry, Pharmacy, FU Berlin, Berlin, Germany
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47
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Nakamura F, Stossel TP, Hartwig JH. The filamins: organizers of cell structure and function. Cell Adh Migr 2011; 5:160-9. [PMID: 21169733 DOI: 10.4161/cam.5.2.14401] [Citation(s) in RCA: 359] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Filamin A (FLNa), the first non-muscle actin filament cross-linking protein, was identified in 1975. Thirty five years of FLNa research has revealed its structure in great detail, discovered its isoforms (FLNb and c), and identified over 90 binding partners including channels, receptors, intracellular signaling molecules, and even transcription factors. Due to this diversity, mutations in human FLN genes result in a wide range of anomalies with moderate to lethal consequences. This review focuses on the structure and functions of FLNa in cell migration and adhesion.
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Affiliation(s)
- Fumihiko Nakamura
- Translational Medicine Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
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Jin J, Kwon YW, Paek JS, Cho HJ, Yu J, Lee JY, Chu IS, Park IH, Park YB, Kim HS, Kim Y. Analysis of differential proteomes of induced pluripotent stem cells by protein-based reprogramming of fibroblasts. J Proteome Res 2011; 10:977-89. [PMID: 21175196 DOI: 10.1021/pr100624f] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The recent generation of induced pluripotent stem (iPS) cells represents a novel opportunity to complement embryonic stem (ES) cell-based approaches. iPS cells can be generated by viral transduction of specific transcription factors, but there is a potential risk of tumorigenicity by random retroviral integration. We have generated novel iPS (sFB-protein-iPS) cells from murine dermal fibroblasts (FVB-sFB) that have ES cell characteristics, using ES cell-derived cell extracts instead of performing viral transduction. Notably, only cell extracts from an ES cell line (C57-mES) on the C57/BL6 background generated iPS cells in our protocol-not an ES cell line (E14-mES) on the 129 background. Hypothesizing that determining the differences in these 2 mES cell lines will provide vital insight into the reprogramming machinery, we performed proteomic and global gene expression analysis by iTRAQ and mRNA microarray, respectively. We observed that pluripotent ES cells and ES cell extract-derived iPS cells had differential proteomes and global gene expression patterns. Notably, reprogramming-competent C57-mES cells highly expressed proteins that regulate protein synthesis and metabolism, compared with reprogramming-incompetent 129-mES cells, suggesting that there is a threshold that protein synthetic machinery must exceed to initiate reprogramming.
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Affiliation(s)
- Jonghwa Jin
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Korea
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Filamin A mediates interactions between cytoskeletal proteins that control cell adhesion. FEBS Lett 2010; 585:18-22. [PMID: 21095189 DOI: 10.1016/j.febslet.2010.11.033] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Revised: 11/09/2010] [Accepted: 11/17/2010] [Indexed: 11/22/2022]
Abstract
Cell adhesion, spreading and migration on extracellular matrices are regulated by complex processes that involve the cytoskeleton and a large array of adhesion receptors, including the β1 integrin. Filamin A is a large, multi-domain, homodimeric actin binding protein that contributes to the mechanical stability of cells and interacts with several proteins that regulate cell adhesion including β1 integrin and several protein kinases. Here we review current data on the structure, mechanical properties and intracellular signaling functions of filamin that regulate cell adhesion. We also consider new data showing that interactions of filamin A with intermediate filaments and protein kinase C enable tight regulation of β1 integrin function and consequently early events in cell adhesion and migration on extracellular matrix proteins.
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50
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Huff Lonergan E, Zhang W, Lonergan SM. Biochemistry of postmortem muscle — Lessons on mechanisms of meat tenderization. Meat Sci 2010; 86:184-95. [DOI: 10.1016/j.meatsci.2010.05.004] [Citation(s) in RCA: 467] [Impact Index Per Article: 33.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2010] [Revised: 04/30/2010] [Accepted: 05/05/2010] [Indexed: 01/09/2023]
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