1
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Huang L, Shao B. New insights of glycoprotein Ib-IX-V complex organization and glycoprotein Ibα in platelet biogenesis. Curr Opin Hematol 2024:00062752-990000000-00081. [PMID: 39046849 DOI: 10.1097/moh.0000000000000832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2024]
Abstract
PURPOSE OF REVIEW Glycoprotein (GP) Ib-IX-V, a platelet surface receptor that plays a critical role in platelet adhesion and platelet-mediated immune responses, consists of GPIbα, GPIbβ, GPIX, and GPV in a stoichiometry of 2 : 4 : 2 : 1. Forming a complex is essential for GPIb-IX-V to function. GPIb-IX-V also plays an important role in platelet biogenesis by regulating the number and size of platelets. Yet how GPIb-IX-V regulates platelet biogenesis remains elusive. This review will summarize recent findings in the complex organization of GPIb-IX-V and its role in platelet biogenesis. RECENT FINDINGS Proteomics studies suggest that GPIbα, GPIbβ, GPIX, and GPV form the complex in a ratio of 1 : 2 : 1 : 1, which is supported by analysis of molecular weight of GPIb-IX-V and GPIb-IX and the structure of entire GPIb-IX-V. To activate platelets, GPIbα requires binding of CLEC-2 to trigger signals. Furthermore, disrupting the GPIbα anchorage to filamin A causes defects in platelet budding away from proplatelets leading to giant platelets and a low platelet count. SUMMARY New studies challenge the traditional model for the organization of GPIb-IX-V as a complex and indicate the role of GPIb-IX-V in platelet production. Those studies provide insights for GPIb-IX-V in the regulation of platelet activation and platelet biogenesis.
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Affiliation(s)
- Lulu Huang
- Laboratory of Vascular Inflammation and Thrombosis Research, Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York, USA
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2
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Mumme H, Thomas BE, Bhasin SS, Krishnan U, Dwivedi B, Perumalla P, Sarkar D, Ulukaya GB, Sabnis HS, Park SI, DeRyckere D, Raikar SS, Pauly M, Summers RJ, Castellino SM, Wechsler DS, Porter CC, Graham DK, Bhasin M. Single-cell analysis reveals altered tumor microenvironments of relapse- and remission-associated pediatric acute myeloid leukemia. Nat Commun 2023; 14:6209. [PMID: 37798266 PMCID: PMC10556066 DOI: 10.1038/s41467-023-41994-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 09/25/2023] [Indexed: 10/07/2023] Open
Abstract
Acute myeloid leukemia (AML) microenvironment exhibits cellular and molecular differences among various subtypes. Here, we utilize single-cell RNA sequencing (scRNA-seq) to analyze pediatric AML bone marrow (BM) samples from diagnosis (Dx), end of induction (EOI), and relapse timepoints. Analysis of Dx, EOI scRNA-seq, and TARGET AML RNA-seq datasets reveals an AML blasts-associated 7-gene signature (CLEC11A, PRAME, AZU1, NREP, ARMH1, C1QBP, TRH), which we validate on independent datasets. The analysis reveals distinct clusters of Dx relapse- and continuous complete remission (CCR)-associated AML-blasts with differential expression of genes associated with survival. At Dx, relapse-associated samples have more exhausted T cells while CCR-associated samples have more inflammatory M1 macrophages. Post-therapy EOI residual blasts overexpress fatty acid oxidation, tumor growth, and stemness genes. Also, a post-therapy T-cell cluster associated with relapse samples exhibits downregulation of MHC Class I and T-cell regulatory genes. Altogether, this study deeply characterizes pediatric AML relapse- and CCR-associated samples to provide insights into the BM microenvironment landscape.
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Affiliation(s)
- Hope Mumme
- Department of Biomedical Informatics, Emory University School of Medicine, Atlanta, GA, USA
| | - Beena E Thomas
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Swati S Bhasin
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Upaasana Krishnan
- Department of Biomedical Informatics, Emory University School of Medicine, Atlanta, GA, USA
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Bhakti Dwivedi
- Department of Biostatistics and Bioinformatics Shared Resource, Winship Cancer Institute, Emory University, Atlanta, GA, USA
| | - Pruthvi Perumalla
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Debasree Sarkar
- Department of Biomedical Informatics, Emory University School of Medicine, Atlanta, GA, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Gulay B Ulukaya
- Department of Biomedical Informatics, Emory University School of Medicine, Atlanta, GA, USA
| | - Himalee S Sabnis
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Sunita I Park
- Department of Pathology, Children's Healthcare of Atlanta, Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA
| | - Deborah DeRyckere
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Sunil S Raikar
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Melinda Pauly
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Ryan J Summers
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Sharon M Castellino
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Daniel S Wechsler
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Christopher C Porter
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Douglas K Graham
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Manoj Bhasin
- Department of Biomedical Informatics, Emory University School of Medicine, Atlanta, GA, USA.
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA.
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA.
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
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3
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Iazzi M, Sadeghi S, Gupta GD. A Proteomic Survey of the Cystic Fibrosis Transmembrane Conductance Regulator Surfaceome. Int J Mol Sci 2023; 24:11457. [PMID: 37511222 PMCID: PMC10380767 DOI: 10.3390/ijms241411457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/08/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023] Open
Abstract
The aim of this review article is to collate recent contributions of proteomic studies to cystic fibrosis transmembrane conductance regulator (CFTR) biology. We summarize advances from these studies and create an accessible resource for future CFTR proteomic efforts. We focus our attention on the CFTR interaction network at the cell surface, thus generating a CFTR 'surfaceome'. We review the main findings about CFTR interactions and highlight several functional categories amongst these that could lead to the discovery of potential biomarkers and drug targets for CF.
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Affiliation(s)
| | | | - Gagan D. Gupta
- Department of Chemistry and Biology, Toronto Metropolitan University, Toronto, ON M5B 2K3, Canada
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4
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Liu J, Lu F, Ithychanda SS, Apostol M, Das M, Deshpande G, Plow EF, Qin J. A mechanism of platelet integrin αIIbβ3 outside-in signaling through a novel integrin αIIb subunit-filamin-actin linkage. Blood 2023; 141:2629-2641. [PMID: 36867840 PMCID: PMC10356577 DOI: 10.1182/blood.2022018333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 02/24/2023] [Accepted: 02/24/2023] [Indexed: 03/05/2023] Open
Abstract
The communication of talin-activated integrin αIIbβ3 with the cytoskeleton (integrin outside-in signaling) is essential for platelet aggregation, wound healing, and hemostasis. Filamin, a large actin crosslinker and integrin binding partner critical for cell spreading and migration, is implicated as a key regulator of integrin outside-in signaling. However, the current dogma is that filamin, which stabilizes inactive αIIbβ3, is displaced from αIIbβ3 by talin to promote the integrin activation (inside-out signaling), and how filamin further functions remains unresolved. Here, we show that while associating with the inactive αIIbβ3, filamin also associates with the talin-bound active αIIbβ3 to mediate platelet spreading. Fluorescence resonance energy transfer-based analysis reveals that while associating with both αIIb and β3 cytoplasmic tails (CTs) to maintain the inactive αIIbβ3, filamin is spatiotemporally rearranged to associate with αIIb CT alone on activated αIIbβ3. Consistently, confocal cell imaging indicates that integrin α CT-linked filamin gradually delocalizes from the β CT-linked focal adhesion marker-vinculin likely because of the separation of integrin α/β CTs occurring during integrin activation. High-resolution crystal and nuclear magnetic resonance structure determinations unravel that the activated integrin αIIb CT binds to filamin via a striking α-helix→β-strand transition with a strengthened affinity that is dependent on the integrin-activating membrane environment containing enriched phosphatidylinositol 4,5-bisphosphate. These data suggest a novel integrin αIIb CT-filamin-actin linkage that promotes integrin outside-in signaling. Consistently, disruption of such linkage impairs the activation state of αIIbβ3, phosphorylation of focal adhesion kinase/proto-oncogene tyrosine kinase Src, and cell migration. Together, our findings advance the fundamental understanding of integrin outside-in signaling with broad implications in blood physiology and pathology.
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Affiliation(s)
- Jianmin Liu
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
| | - Fan Lu
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH
| | - Sujay Subbayya Ithychanda
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
| | - Marcin Apostol
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
| | - Mitali Das
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
| | - Gauravi Deshpande
- Imaging Core, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
| | - Edward F. Plow
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
| | - Jun Qin
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH
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5
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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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6
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Gerlevik U, Saygı C, Cangül H, Kutlu A, Çaralan EF, Topçu Y, Özören N, Sezerman OU. Computational analysis of missense filamin-A variants, including the novel p.Arg484Gln variant of two brothers with periventricular nodular heterotopia. PLoS One 2022; 17:e0265400. [PMID: 35613087 PMCID: PMC9132340 DOI: 10.1371/journal.pone.0265400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 03/01/2022] [Indexed: 12/01/2022] Open
Abstract
Background Periventricular nodular heterotopia (PNH) is a cell migration disorder associated with mutations in Filamin-A (FLNA) gene on chromosome X. Majority of the individuals with PNH-associated FLNA mutations are female whereas liveborn males with FLNA mutations are very rare. Fetal viability of the males seems to depend on the severity of the variant. Splicing or severe truncations presumed loss of function of the protein product, lead to male lethality and only partial-loss-of-function variants are reported in surviving males. Those variants mostly manifest milder clinical phenotypes in females and thus avoid detection of the disease in females. Methods We describe a novel p.Arg484Gln variant in the FLNA gene by performing whole exome analysis on the index case, his one affected brother and his healthy non-consanguineous parents. The transmission of PNH from a clinically asymptomatic mother to two sons is reported in a fully penetrant classical X-linked dominant mode. The variant was verified via Sanger sequencing. Additionally, we investigated the impact of missense mutations reported in affected males on the FLNa protein structure, dynamics and interactions by performing molecular dynamics (MD) simulations to examine the disease etiology and possible compensative mechanisms allowing survival of the males. Results We observed that p.Arg484Gln disrupts the FLNa by altering its structural and dynamical properties including the flexibility of certain regions, interactions within the protein, and conformational landscape of FLNa. However, these impacts existed for only a part the MD trajectories and highly similar patterns observed in the other 12 mutations reported in the liveborn males validated this mechanism. Conclusion It is concluded that the variants seen in the liveborn males result in transient pathogenic effects, rather than persistent impairments. By this way, the protein could retain its function occasionally and results in the survival of the males besides causing the disease.
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Affiliation(s)
- Umut Gerlevik
- Department of Biostatistics and Bioinformatics, Institute of Health Sciences, Acibadem Mehmet Ali Aydınlar University, Istanbul, Turkey
| | - Ceren Saygı
- Department of Molecular Biology and Genetics, Boğaziçi University, Istanbul, Turkey
| | - Hakan Cangül
- Center for Genetic Diagnosis, Istanbul Medipol University, Istanbul, Turkey
| | - Aslı Kutlu
- Department of Biostatistics and Bioinformatics, Institute of Health Sciences, Acibadem Mehmet Ali Aydınlar University, Istanbul, Turkey
- Bioinformatics & Genetics, Faculty of Engineering and Natural Science, İstinye University, İstanbul, Turkey
| | | | - Yasemin Topçu
- Department of Pediatric Neurology, Faculty of Medicine, Istanbul Medipol University, Istanbul, Turkey
| | - Nesrin Özören
- Department of Molecular Biology and Genetics, Boğaziçi University, Istanbul, Turkey
| | - Osman Uğur Sezerman
- Department of Biostatistics and Bioinformatics, Institute of Health Sciences, Acibadem Mehmet Ali Aydınlar University, Istanbul, Turkey
- Department of Biostatistics and Medical Informatics, School of Medicine, Acıbadem Mehmet Ali Aydınlar University, Istanbul, Turkey
- * E-mail:
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7
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Duan B, Qin Z, Gu X, Li Y. Migfilin: Cell Adhesion Effect and Comorbidities. Onco Targets Ther 2022; 15:411-422. [PMID: 35469339 PMCID: PMC9034862 DOI: 10.2147/ott.s357355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 04/04/2022] [Indexed: 11/28/2022] Open
Abstract
Cell adhesion manifests as cell linkages to neighboring cells and/or the extracellular matrix (ECM). Migfilin is a widely expressed adhesion protein. It comprises three LIM domains in the C-terminal region and one proline-rich sequence in the N-terminal region. Through interplay with its various binding partners, such as Kindlin-2, Filamin, vasodilator-stimulated phosphoprotein (VASP) protein and the transcription factor CSX, Migfilin facilitates the dynamic association of connecting actomyosin fibers, orchestrating cell morphogenetic movement and cell adhesion, proliferation, migration, invasion, differentiation and signal transduction. In this review, to further elucidate the functional contributions of and pathogenesis induced by Migfilin, we focused on the structure of Migfilin and the targets which it directly binds with. We also summarized the role of Migfilin and its binding partners in the progression of different diseases and malignancies. As a possible candidate for coordinating various cellular processes and because of its association with both the pathogenesis and progression of certain tumors, Migfilin likely has utility as a therapeutic target against multiple diseases in the clinic.
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Affiliation(s)
- Baoyu Duan
- Department of Pharmacy, Shanghai University of Medicine and Health Sciences, Shanghai, People’s Republic of China
| | - Ziyao Qin
- Department of Research and Development, Shanghai Institute of Biological Products Co., Ltd., Shanghai, People’s Republic of China
| | - Xuefeng Gu
- Department of Pharmacy, Shanghai University of Medicine and Health Sciences, Shanghai, People’s Republic of China
- Xuefeng Gu, Department of Pharmacy, 279 Zhouzhu Road, Shanghai, 201318, People’s Republic of China, Tel +86 21 6588 3180, Email
| | - Yanfei Li
- Shanghai University of Medicine and Health Sciences Affiliated Zhoupu Hospital, Shanghai, People’s Republic of China
- Correspondence: Yanfei Li, Shanghai University of Medicine and Health Sciences Affiliated Zhoupu Hospital, 1500 Zhouyuan Road, Shanghai, 201318, People’s Republic of China, Tel +86 21 6588 3180 Email
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CRACking the Molecular Regulatory Mechanism of SOCE during Platelet Activation in Thrombo-Occlusive Diseases. Cells 2022; 11:cells11040619. [PMID: 35203269 PMCID: PMC8870035 DOI: 10.3390/cells11040619] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 01/31/2022] [Accepted: 02/09/2022] [Indexed: 11/16/2022] Open
Abstract
Thrombo-occlusive diseases such as myocardial infarction, ischemic stroke and deep vein thrombosis with subsequent pulmonary embolism still represent a major health burden worldwide. Besides the cells of the vasculature or other hematopoietic cells, platelets are primarily responsible for the development and progression of an occluding thrombus. The activation and function of platelets crucially depend on free cytosolic calcium (Ca2+) as second messenger, which modulates platelet secretion, aggregation and thrombus formation. Ca2+ is elevated upon platelet activation by release of Ca2+ from intracellular stores thus triggering of the subsequent store-operated Ca2+ entry (SOCE), which is facilitated by Ca2+ release-activated channels (CRACs). In general, CRACs are assembled by the pore-forming unit Orai in the plasma membrane and the Ca2+-sensing stromal interaction molecule (STIM) in the endoplasmic reticulum after the depletion of internal Ca2+ stores. In the last few years, there is a growing body of the literature demonstrating the importance of STIM and Orai-mediated mechanism in thrombo-occlusive disorders. Thus, this review provides an overview of the recent understanding of STIM and Orai signaling in platelet function and its implication in the development and progression of ischemic thrombo-occlusive disorders. Moreover, potential pharmacological implications of STIM and Orai signaling in platelets are anticipated and discussed in the end.
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Abu-Arish A, Pandžić E, Luo Y, Sato Y, Turner MJ, Wiseman PW, Hanrahan JW. Lipid-driven CFTR clustering is impaired in CF and restored by corrector drugs. J Cell Sci 2022; 135:274066. [PMID: 35060604 PMCID: PMC8976878 DOI: 10.1242/jcs.259002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 01/08/2022] [Indexed: 11/20/2022] Open
Abstract
Membrane proteins often cluster in nanoscale membrane domains (lipid rafts) that coalesce into ceramide-rich platforms during cell stress, however the clustering mechanisms remain uncertain. The cystic fibrosis transmembrane conductance regulator (CFTR), which is mutated in cystic fibrosis (CF), forms clusters that are cholesterol-dependent and become incorporated into long-lived platforms during hormonal stimulation. We report here that clustering does not involve known tethering interactions of CFTR with PDZ domain proteins, filamin A or the actin cytoskeleton. It also does not require CFTR palmitoylation but is critically dependent on membrane lipid order and is induced by detergents that increase the phase separation of membrane lipids. Clustering and integration of CFTR into ceramide-rich platforms are abolished by the disease mutations F508del and S13F and rescued by the CFTR modulators elexacaftor+tezacaftor. These results indicate CF therapeutics that correct mutant protein folding restore both trafficking and normal lipid interactions in the plasma membrane.
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Affiliation(s)
- Asmahan Abu-Arish
- Department of Physiology, McGill University, Montréal QC H3G 1Y6, Canada
- Cystic Fibrosis Translational Research centre, McGill University, Canada
| | - Elvis Pandžić
- UNSW Australia, Biomedical Imaging Facility, Mark Wainwright Analytical Center, Sydney, Australia
| | - Yishan Luo
- Department of Physiology, McGill University, Montréal QC H3G 1Y6, Canada
- Cystic Fibrosis Translational Research centre, McGill University, Canada
| | - Yukiko Sato
- Department of Physiology, McGill University, Montréal QC H3G 1Y6, Canada
- Cystic Fibrosis Translational Research centre, McGill University, Canada
| | - Mark J. Turner
- Department of Physiology, McGill University, Montréal QC H3G 1Y6, Canada
- Cystic Fibrosis Translational Research centre, McGill University, Canada
| | - Paul W. Wiseman
- Department of Chemistry and Department of Physics, McGill University, Montréal, QC, Canada
| | - John W. Hanrahan
- Department of Physiology, McGill University, Montréal QC H3G 1Y6, Canada
- Cystic Fibrosis Translational Research centre, McGill University, Canada
- Research Institute of the McGill University Health Centre, Canada
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Misra S, Ghatak S, Moreno-Rodriguez RA, Norris RA, Hascall VC, Markwald RR. Periostin/Filamin-A: A Candidate Central Regulatory Axis for Valve Fibrogenesis and Matrix Compaction. Front Cell Dev Biol 2021; 9:649862. [PMID: 34150753 PMCID: PMC8209548 DOI: 10.3389/fcell.2021.649862] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 04/07/2021] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Discoveries in the identification of transcription factors, growth factors and extracellular signaling molecules have led to the detection of downstream targets that modulate valvular tissue organization that occurs during development, aging, or disease. Among these, matricellular protein, periostin, and cytoskeletal protein filamin A are highly expressed in developing heart valves. The phenotype of periostin null indicates that periostin promotes migration, survival, and differentiation of valve interstitial cushion cells into fibroblastic lineages necessary for postnatal valve remodeling/maturation. Genetically inhibiting filamin A expression in valve interstitial cushion cells mirrored the phenotype of periostin nulls, suggesting a molecular interaction between these two proteins resulted in poorly remodeled valve leaflets that might be prone to myxomatous over time. We examined whether filamin A has a cross-talk with periostin/signaling that promotes remodeling of postnatal heart valves into mature leaflets. RESULTS We have previously shown that periostin/integrin-β1 regulates Pak1 activation; here, we revealed that the strong interaction between Pak1 and filamin A proteins was only observed after stimulation of VICs with periostin; suggesting that periostin/integrin-β-mediated interaction between FLNA and Pak1 may have a functional role in vivo. We found that FLNA phosphorylation (S2152) is activated by Pak1, and this interaction was observed after stimulation with periostin/integrin-β1/Cdc42/Rac1 signaling; consequently, FLNA binding to Pak1 stimulates its kinase activity. Patients with floppy and/or prolapsed mitral valves, when genetically screened, were found to have point mutations in the filamin A gene at P637Q and G288R. Expression of either of these filamin A mutants failed to increase the magnitude of filamin A (S2152) expression, Pak1-kinase activity, actin polymerization, and differentiation of VICs into mature mitral valve leaflets in response to periostin signaling. CONCLUSION PN-stimulated bidirectional interaction between activated FLNA and Pak1 is essential for actin cytoskeletal reorganization and the differentiation of immature VICs into mature valve leaflets.
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Affiliation(s)
- Suniti Misra
- Department of Biochemistry and Molecular Biology, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States
| | - Shibnath Ghatak
- Department of Biochemistry and Molecular Biology, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States
| | - Ricardo A. Moreno-Rodriguez
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC, United States
| | - Russell A. Norris
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC, United States
| | - Vincent C. Hascall
- Department of Biomedical Engineering/ND20, Cleveland Clinic, Cleveland, OH, United States
| | - Roger R. Markwald
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC, United States
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11
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Lamsoul I, Dupré L, Lutz PG. Molecular Tuning of Filamin A Activities in the Context of Adhesion and Migration. Front Cell Dev Biol 2020; 8:591323. [PMID: 33330471 PMCID: PMC7714767 DOI: 10.3389/fcell.2020.591323] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 11/05/2020] [Indexed: 01/08/2023] Open
Abstract
The dynamic organization of actin cytoskeleton meshworks relies on multiple actin-binding proteins endowed with distinct actin-remodeling activities. Filamin A is a large multi-domain scaffolding protein that cross-links actin filaments with orthogonal orientation in response to various stimuli. As such it plays key roles in the modulation of cell shape, cell motility, and differentiation throughout development and adult life. The essentiality and complexity of Filamin A is highlighted by mutations that lead to a variety of severe human disorders affecting multiple organs. One of the most conserved activity of Filamin A is to bridge the actin cytoskeleton to integrins, thereby maintaining the later in an inactive state. We here review the numerous mechanisms cells have developed to adjust Filamin A content and activity and focus on the function of Filamin A as a gatekeeper to integrin activation and associated adhesion and motility.
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Affiliation(s)
- Isabelle Lamsoul
- Centre de Physiopathologie de Toulouse Purpan, INSERM, CNRS, Université de Toulouse, UPS, Toulouse, France
| | - Loïc Dupré
- Centre de Physiopathologie de Toulouse Purpan, INSERM, CNRS, Université de Toulouse, UPS, Toulouse, France.,Ludwig Boltzmann Institute for Rare and Undiagnosed Diseases, Vienna, Austria
| | - Pierre G Lutz
- Centre de Physiopathologie de Toulouse Purpan, INSERM, CNRS, Université de Toulouse, UPS, Toulouse, France
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12
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Wade EM, Halliday BJ, Jenkins ZA, O'Neill AC, Robertson SP. The X‐linked filaminopathies: Synergistic insights from clinical and molecular analysis. Hum Mutat 2020; 41:865-883. [DOI: 10.1002/humu.24002] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 01/30/2020] [Accepted: 02/24/2020] [Indexed: 12/17/2022]
Affiliation(s)
- Emma M. Wade
- Department of Women's and Children's Health, Dunedin School of MedicineUniversity of Otago Dunedin New Zealand
| | - Benjamin J. Halliday
- Department of Women's and Children's Health, Dunedin School of MedicineUniversity of Otago Dunedin New Zealand
| | - Zandra A. Jenkins
- Department of Women's and Children's Health, Dunedin School of MedicineUniversity of Otago Dunedin New Zealand
| | - Adam C. O'Neill
- Department of Women's and Children's Health, Dunedin School of MedicineUniversity of Otago Dunedin New Zealand
| | - Stephen P. Robertson
- Department of Women's and Children's Health, Dunedin School of MedicineUniversity of Otago Dunedin New Zealand
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13
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Filamin A: key actor in platelet biology. Blood 2020; 134:1279-1288. [PMID: 31471375 DOI: 10.1182/blood.2019000014] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 08/13/2019] [Indexed: 12/19/2022] Open
Abstract
Filamins (FLNs) are large dimeric actin-binding proteins that regulate actin cytoskeleton remodeling. In addition, FLNs serve as scaffolds for signaling proteins, such as tyrosine kinases, GTPases, or phosphatases, as well as for adhesive receptors, such as integrins. Thus, they connect adhesive receptors to signaling pathways and to cytoskeleton. There are 3 isoforms of FLN (filamin a [FLNa], FLNb, FLNc) that originate from 3 homologous genes. FLNa has been the recent focus of attention because its mutations are responsible for a wide spectrum of defects called filaminopathies A, affecting brain (peri-ventricular nodular heterotopia), heart (valve defect), skeleton, gastrointestinal tract, and, more recently, the megakaryocytic lineage. This review will focus on the physiological and pathological roles of FLNa in platelets. Indeed, FLNa mutations alter platelet production from their bone marrow precursors, the megakaryocytes, yielding giant platelets in reduced numbers (macrothrombocytopenia). In platelets per se, FLNa mutations may lead to impaired αIIbβ3 integrin activation or in contrast, increased αIIbβ3 activation, potentially enhancing the risk of thrombosis. Experimental work delineating the interaction of FLNa with its platelet partners, including αIIbβ3, the von Willebrand factor receptor GPIb-IX-V, the tyrosine kinase Syk, and the signaling pathway of the collagen receptor GPVI, will also be reviewed.
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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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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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16
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17
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Haataja TJK, Bernardi RC, Lecointe S, Capoulade R, Merot J, Pentikäinen U. Non-syndromic Mitral Valve Dysplasia Mutation Changes the Force Resilience and Interaction of Human Filamin A. Structure 2018; 27:102-112.e4. [PMID: 30344108 DOI: 10.1016/j.str.2018.09.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 07/24/2018] [Accepted: 09/18/2018] [Indexed: 01/03/2023]
Abstract
Filamin A (FLNa), expressed in endocardial endothelia during fetal valve morphogenesis, is key in cardiac development. Missense mutations in FLNa cause non-syndromic mitral valve dysplasia (FLNA-MVD). Here, we aimed to reveal the currently unknown underlying molecular mechanism behind FLNA-MVD caused by the FLNa P637Q mutation. The solved crystal structure of the FLNa3-5 P637Q revealed that this mutation causes only minor structural changes close to mutation site. These changes were observed to significantly affect FLNa's ability to transmit cellular force and to interact with its binding partner. The performed steered molecular dynamics simulations showed that significantly lower forces are needed to split domains 4 and 5 in FLNA-MVD than with wild-type FLNa. The P637Q mutation was also observed to interfere with FLNa's interactions with the protein tyrosine phosphatase PTPN12. Our results provide a crucial step toward understanding the molecular bases behind FLNA-MVD, which is critical for the development of drug-based therapeutics.
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Affiliation(s)
- Tatu J K Haataja
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, 40014 Jyväskylä, Finland
| | - Rafael C Bernardi
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Simon Lecointe
- L'institut du Thorax, INSERM, CNRS, UNIV Nantes, Nantes, France
| | | | - Jean Merot
- L'institut du Thorax, INSERM, CNRS, UNIV Nantes, Nantes, France
| | - Ulla Pentikäinen
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, 40014 Jyväskylä, Finland; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Institute of Biomedicine, University of Turku, 20520 Turku, Finland; Turku Centre for Biotechnology, University of Turku, 20520 Turku, Finland.
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18
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Lopez JJ, Albarrán L, Jardín I, Sanchez-Collado J, Redondo PC, Bermejo N, Bobe R, Smani T, Rosado JA. Filamin A Modulates Store-Operated Ca2+Entry by Regulating STIM1 (Stromal Interaction Molecule 1)–Orai1 Association in Human Platelets. Arterioscler Thromb Vasc Biol 2018; 38:386-397. [DOI: 10.1161/atvbaha.117.310139] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2017] [Accepted: 12/13/2017] [Indexed: 12/23/2022]
Affiliation(s)
- Jose J. Lopez
- From the Department of Physiology, University of Extremadura, Cáceres, Spain (J.J.L., L.A., I.J., J.S.-C., P.C.R., J.A.R.); Department of Hematology, Hospital San Pedro de Alcantara, Cáceres, Spain (N.B.); INSERM Unité Mixte de Recherche-Santé 1176, Université Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France (R.B.); and Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Spain (T.S.)
| | - Letizia Albarrán
- From the Department of Physiology, University of Extremadura, Cáceres, Spain (J.J.L., L.A., I.J., J.S.-C., P.C.R., J.A.R.); Department of Hematology, Hospital San Pedro de Alcantara, Cáceres, Spain (N.B.); INSERM Unité Mixte de Recherche-Santé 1176, Université Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France (R.B.); and Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Spain (T.S.)
| | - Isaac Jardín
- From the Department of Physiology, University of Extremadura, Cáceres, Spain (J.J.L., L.A., I.J., J.S.-C., P.C.R., J.A.R.); Department of Hematology, Hospital San Pedro de Alcantara, Cáceres, Spain (N.B.); INSERM Unité Mixte de Recherche-Santé 1176, Université Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France (R.B.); and Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Spain (T.S.)
| | - Jose Sanchez-Collado
- From the Department of Physiology, University of Extremadura, Cáceres, Spain (J.J.L., L.A., I.J., J.S.-C., P.C.R., J.A.R.); Department of Hematology, Hospital San Pedro de Alcantara, Cáceres, Spain (N.B.); INSERM Unité Mixte de Recherche-Santé 1176, Université Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France (R.B.); and Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Spain (T.S.)
| | - Pedro C. Redondo
- From the Department of Physiology, University of Extremadura, Cáceres, Spain (J.J.L., L.A., I.J., J.S.-C., P.C.R., J.A.R.); Department of Hematology, Hospital San Pedro de Alcantara, Cáceres, Spain (N.B.); INSERM Unité Mixte de Recherche-Santé 1176, Université Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France (R.B.); and Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Spain (T.S.)
| | - Nuria Bermejo
- From the Department of Physiology, University of Extremadura, Cáceres, Spain (J.J.L., L.A., I.J., J.S.-C., P.C.R., J.A.R.); Department of Hematology, Hospital San Pedro de Alcantara, Cáceres, Spain (N.B.); INSERM Unité Mixte de Recherche-Santé 1176, Université Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France (R.B.); and Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Spain (T.S.)
| | - Regis Bobe
- From the Department of Physiology, University of Extremadura, Cáceres, Spain (J.J.L., L.A., I.J., J.S.-C., P.C.R., J.A.R.); Department of Hematology, Hospital San Pedro de Alcantara, Cáceres, Spain (N.B.); INSERM Unité Mixte de Recherche-Santé 1176, Université Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France (R.B.); and Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Spain (T.S.)
| | - Tarik Smani
- From the Department of Physiology, University of Extremadura, Cáceres, Spain (J.J.L., L.A., I.J., J.S.-C., P.C.R., J.A.R.); Department of Hematology, Hospital San Pedro de Alcantara, Cáceres, Spain (N.B.); INSERM Unité Mixte de Recherche-Santé 1176, Université Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France (R.B.); and Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Spain (T.S.)
| | - Juan A. Rosado
- From the Department of Physiology, University of Extremadura, Cáceres, Spain (J.J.L., L.A., I.J., J.S.-C., P.C.R., J.A.R.); Department of Hematology, Hospital San Pedro de Alcantara, Cáceres, Spain (N.B.); INSERM Unité Mixte de Recherche-Santé 1176, Université Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France (R.B.); and Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Spain (T.S.)
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19
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Peverelli E, Giardino E, Treppiedi D, Catalano R, Mangili F, Locatelli M, Lania AG, Arosio M, Spada A, Mantovani G. A novel pathway activated by somatostatin receptor type 2 (SST2): Inhibition of pituitary tumor cell migration and invasion through cytoskeleton protein recruitment. Int J Cancer 2017; 142:1842-1852. [PMID: 29226331 DOI: 10.1002/ijc.31205] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 11/15/2017] [Accepted: 12/05/2017] [Indexed: 12/14/2022]
Abstract
The pharmacological therapy of GH-secreting pituitary tumors is based on somatostatin (SS) analogs that reduce GH secretion and cell proliferation by binding mainly SS receptors type 2 (SST2). Antimigratory effects of SS have been demonstrated in different cell models, but no data on pituitary tumors are available. Aims of our study were to evaluate SST2 effects on migration and invasion of human and rat tumoral somatotrophs, and to elucidate the molecular mechanism involved focusing on the role of cofilin and filamin A (FLNA). Our data revealed that SST2 agonist BIM23120 significantly reduced GH3 cells migration (-22% ± 3.6%, p < 0.001) and invasion on collagen IV (-31.3% ± 12.2%, p < 0.01), both these effects being reproduced by octreotide and pasireotide. Similar results were obtained in primary cultured cells from human GH-secreting tumors. These inhibitory actions were accompanied by a marked increase in RhoA/ROCK-dependent cofilin phosphorylation (about 2.7-fold in GH3 and 2.1-fold in human primary cells). Accordingly, the anti-invasive effect of the SS analog was mimicked by the overexpression in GH3 cells of the S3D phosphomimetic cofilin mutant, and abolished by both phosphodeficient S3A cofilin and a specific ROCK inhibitor that prevented cofilin phosphorylation. Moreover, FLNA silencing and FLNA dominant-negative mutants FLNA19-20 and FLNA21-24 transfection demonstrated that FLNA plays a scaffold function for SST2-mediated cofilin phosphorylation. Accordingly, cofilin recruitment to agonist-activated SST2 was completely lost in FLNA silenced cells. In conclusion, we demonstrated that SST2 inhibits rat and human tumoral somatotrophs migration and invasion through a molecular mechanism that involves FLNA-dependent cofilin recruitment and phosphorylation.
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Affiliation(s)
- E Peverelli
- 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
| | - D Treppiedi
- 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
| | - F Mangili
- Endocrinology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - M Locatelli
- Neurosurgery Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - A G Lania
- Endocrinology Unit, IRCCS Humanitas Research Hospital, Humanitas University, Rozzano, 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
| | - G Mantovani
- 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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20
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Ishizuka K, Tabata H, Ito H, Kushima I, Noda M, Yoshimi A, Usami M, Watanabe K, Morikawa M, Uno Y, Okada T, Mori D, Aleksic B, Ozaki N, Nagata KI. Possible involvement of a cell adhesion molecule, Migfilin, in brain development and pathogenesis of autism spectrum disorders. J Neurosci Res 2017; 96:789-802. [PMID: 29114925 DOI: 10.1002/jnr.24194] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 10/06/2017] [Accepted: 10/09/2017] [Indexed: 11/07/2022]
Abstract
Migfilin, encoded by FBLIM1 at the 1p36 locus, is a multi-domain adaptor protein essential for various cellular processes such as cell morphology and migration. Small deletions and duplications at the 1p36 locus, monosomy of which results in neurodevelopmental disorders and multiple congenital anomalies, have also been identified in patients with autism spectrum disorder (ASD). However, the impact of FBLIM1, the gene within 1p36, on the pathogenesis of ASD is unknown. In this study, we performed morphological analyses of migfilin to elucidate its role in brain development. Migfilin was detected specifically in the embryonic and perinatal stages of the mouse brain. Either silencing or overexpression of migfilin in embryos following in utero electroporation disrupted Neocortical neuronal migration. Additionally, neurite elongation was impaired when migfilin was silenced in cultured mouse hippocampal neurons. We then screened FBLIM1 for rare exonic deletions/duplications in 549 Japanese ASD patients and 824 controls, detecting one case of ASD and intellectual delay that harbored a 26-kb deletion at 1p36.21 that solely included the C-terminal exon of FBLIM1. The FBLIM1 mRNA expression level in this case was reduced compared to levels in individuals without FBLIM1 deletion. Our findings indicate that tightly regulated expression of migfilin is essential for neuronal development and that FBLIM1 disruption may be related to the phenotypes associated with ASD and related neurodevelopmental disorders.
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Affiliation(s)
- Kanako Ishizuka
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Hidenori Tabata
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Human Service Center, Kasugai, Japan
| | - Hidenori Ito
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Human Service Center, Kasugai, Japan
| | - Itaru Kushima
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Mariko Noda
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Human Service Center, Kasugai, Japan
| | - Akira Yoshimi
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Masahide Usami
- Department of Child and Adolescent Psychiatry, Kohnodai Hospital, National Center for Global Health and Medicine, Ichikawa, Japan
| | - Kyota Watanabe
- Hiroshima City Center for Children's Health and Development, Hiroshima, Japan
| | - Mako Morikawa
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yota Uno
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Takashi Okada
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Daisuke Mori
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Branko Aleksic
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Norio Ozaki
- Department of Psychiatry, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Koh-Ichi Nagata
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Human Service Center, Kasugai, Japan.,Department of Neurochemistry, Nagoya University Graduate School of Medicine, Nagoya, Japan
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21
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Seppälä J, Bernardi RC, Haataja TJK, Hellman M, Pentikäinen OT, Schulten K, Permi P, Ylänne J, Pentikäinen U. Skeletal Dysplasia Mutations Effect on Human Filamins' Structure and Mechanosensing. Sci Rep 2017; 7:4218. [PMID: 28652603 PMCID: PMC5484675 DOI: 10.1038/s41598-017-04441-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 05/16/2017] [Indexed: 01/08/2023] Open
Abstract
Cells' ability to sense mechanical cues in their environment is crucial for fundamental cellular processes, leading defects in mechanosensing to be linked to many diseases. The actin cross-linking protein Filamin has an important role in the conversion of mechanical forces into biochemical signals. Here, we reveal how mutations in Filamin genes known to cause Larsen syndrome and Frontometaphyseal dysplasia can affect the structure and therefore function of Filamin domains 16 and 17. Employing X-ray crystallography, the structure of these domains was first solved for the human Filamin B. The interaction seen between domains 16 and 17 is broken by shear force as revealed by steered molecular dynamics simulations. The effects of skeletal dysplasia associated mutations of the structure and mechanosensing properties of Filamin were studied by combining various experimental and theoretical techniques. The results showed that Larsen syndrome associated mutations destabilize or even unfold domain 17. Interestingly, those Filamin functions that are mediated via domain 17 interactions with other proteins are not necessarily affected as strongly interacting peptide binding to mutated domain 17 induces at least partial domain folding. Mutation associated to Frontometaphyseal dysplasia, in turn, transforms 16-17 fragment from compact to an elongated form destroying the force-regulated domain pair.
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Affiliation(s)
- Jonne Seppälä
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyvaskyla, P.O Box 35, Survontie 9 C, FI-40014, Jyvaskyla, Finland
| | - Rafael C Bernardi
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Champaign, 61801, USA
| | - Tatu J K Haataja
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyvaskyla, P.O Box 35, Survontie 9 C, FI-40014, Jyvaskyla, Finland
| | - Maarit Hellman
- Department of Chemistry, University of Jyvaskyla, P.O Box 35, Survontie 9 C, FI-40014, Jyvaskyla, Finland
| | - Olli T Pentikäinen
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyvaskyla, P.O Box 35, Survontie 9 C, FI-40014, Jyvaskyla, Finland
| | - Klaus Schulten
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Champaign, 61801, USA
- Department of Physics, University of Illinois at Urbana-Champaign, Champaign, 61801, USA
| | - Perttu Permi
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyvaskyla, P.O Box 35, Survontie 9 C, FI-40014, Jyvaskyla, Finland
- Department of Chemistry, University of Jyvaskyla, P.O Box 35, Survontie 9 C, FI-40014, Jyvaskyla, Finland
| | - Jari Ylänne
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyvaskyla, P.O Box 35, Survontie 9 C, FI-40014, Jyvaskyla, Finland
| | - Ulla Pentikäinen
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyvaskyla, P.O Box 35, Survontie 9 C, FI-40014, Jyvaskyla, Finland.
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22
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Ithychanda SS, Dou K, Robertson SP, Qin J. Structural and thermodynamic basis of a frontometaphyseal dysplasia mutation in filamin A. J Biol Chem 2017; 292:8390-8400. [PMID: 28348077 DOI: 10.1074/jbc.m117.776740] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 03/10/2017] [Indexed: 01/12/2023] Open
Abstract
Filamin-mediated linkages between transmembrane receptors (TR) and the actin cytoskeleton are crucial for regulating many cytoskeleton-dependent cellular processes such as cell shape change and migration. A major TR binding site in the immunoglobulin repeat 21 (Ig21) of filamin is masked by the adjacent repeat Ig20, resulting in autoinhibition. The TR binding to this site triggers the relief of Ig20 and protein kinase A (PKA)-mediated phosphorylation of Ser-2152, thereby dynamically regulating the TR-actin linkages. A P2204L mutation in Ig20 reportedly cause frontometaphyseal dysplasia, a skeletal disorder with unknown pathogenesis. We show here that the P2204L mutation impairs a hydrophobic core of Ig20, generating a conformationally fluctuating molten globule-like state. Consequently, unlike in WT filamin, where PKA-mediated Ser-2152 phosphorylation is ligand-dependent, the P2204L mutant is readily accessible to PKA, promoting ligand-independent phosphorylation on Ser-2152. Strong TR peptide ligands from platelet GP1bα and G-protein-coupled receptor MAS effectively bound Ig21 by displacing Ig20 from autoinhibited WT filamin, but surprisingly, the capacity of these ligands to bind the P2204L mutant was much reduced despite the mutation-induced destabilization of the Ig20 structure that supposedly weakens the autoinhibition. Thermodynamic analysis indicated that compared with WT filamin, the conformationally fluctuating state of the Ig20 mutant makes Ig21 enthalpically favorable to bind ligand but with substantial entropic penalty, resulting in total higher free energy and reduced ligand affinity. Overall, our results reveal an unusual structural and thermodynamic basis for the P2204L-induced dysfunction of filamin and frontometaphyseal dysplasia disease.
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Affiliation(s)
- Sujay S Ithychanda
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Kevin Dou
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | | | - Jun Qin
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195.
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Neethling A, Mouton J, Loos B, Corfield V, de Villiers C, Kinnear C. Filamin C: a novel component of the KCNE2 interactome during hypoxia. Cardiovasc J Afr 2016; 27:4-11. [PMID: 26956495 PMCID: PMC4816932 DOI: 10.5830/cvja-2015-049] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 05/17/2015] [Indexed: 12/16/2022] Open
Abstract
Aim KCNE2 encodes for the potassium voltage-gated channel, KCNE2. Mutations in KCNE2 have been associated with long-QT syndrome (LQTS). While KCNE2 has been extensively studied, the functions of its C-terminal domain remain inadequately described. Here, we aimed to elucidate the functions of this domain by identifying its protein interactors using yeast two-hybrid analysis. Methods The C-terminal domain of KCNE2 was used as bait to screen a human cardiac cDNA library for putative interacting proteins. Co-localisation and co-immunoprecipitation analyses were used for verification. Results Filamin C (FLNC) was identified as a putative interactor with KCNE2. FLNC and KCNE2 co-localised within the cell, however, a physical interaction was only observed under hypoxic conditions. Conclusion The identification of FLNC as a novel KCNE2 ligand not only enhances current understanding of ion channel function and regulation, but also provides valuable information about possible pathways likely to be involved in LQTS pathogenesis.
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Affiliation(s)
- Annika Neethling
- DST/NRF Centre of Excellence in Biomedical Tuberculosis Research, SA MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, South Africa
| | - Jomien Mouton
- DST/NRF Centre of Excellence in Biomedical Tuberculosis Research, SA MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, South Africa
| | - Ben Loos
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa
| | - Valerie Corfield
- DST/NRF Centre of Excellence in Biomedical Tuberculosis Research, SA MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, South Africa
| | - Carin de Villiers
- DST/NRF Centre of Excellence in Biomedical Tuberculosis Research, SA MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, South Africa
| | - Craig Kinnear
- DST/NRF Centre of Excellence in Biomedical Tuberculosis Research, SA MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, South Africa
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24
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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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25
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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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26
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Krebs K, Ruusmann A, Simonlatser G, Velling T. Expression of FLNa in human melanoma cells regulates the function of integrin α1β1 and phosphorylation and localisation of PKB/AKT/ERK1/2 kinases. Eur J Cell Biol 2015; 94:564-75. [PMID: 26572583 DOI: 10.1016/j.ejcb.2015.10.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 10/23/2015] [Accepted: 10/29/2015] [Indexed: 11/20/2022] Open
Abstract
FLNa is a ubiquitous cytoskeletal protein that links transmembrane receptors, including integrins, to F-actin and functions as a signalling intermediate. We investigated FLNa's role in the function of integrin-type collagen receptors, EGF-EGFR signalling and regulation of PKB/Akt and ERK1/2. Using FLNa-deficient M2 human melanoma cells, and same cells expressing EGFP-FLNa (M2F) or its Ig-like repeats 1-8+24, 8-15+24 and 16-24, we found that in M2F and M2 8-15+24 cells, EGF induced the increased phosphorylation of PKB/Akt and ERK1/2. In M2F cells EGF induced the localisation of these kinases to cell nucleus and lamellipodia, respectively, and the ERK1/2 phosphorylation-dependent co-immunoprecipitation of FLNa with ERK1/2. Only M2F and M2 8-15+24 cells adhered to and spread on type I collagen whereas on fibronectin all cells behaved similarly. α1β1 and α2β1 were the integrin-type collagen receptors expressed on these cells with primarily α1β1 localising to focal contacts and affecting cell adhesion and migration in a manner dependent on FLNa or its Ig-like repeats 8-15. Our results suggest a role for FLNa repeats 8-15 in the α1-subunit-dependent regulation of integrin α1β1 function, EGF-EGFR signalling to PKB/Akt and ERK1/2, identify ERK1/2 in EGF-induced FLNa-associated protein complexes, and show that the function of different integrins is subjected to differential regulation by FLNa.
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Affiliation(s)
- Kristi Krebs
- Institute of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| | - Anu Ruusmann
- Institute of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| | - Grethel Simonlatser
- Institute of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| | - Teet Velling
- Institute of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia.
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27
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Abstract
Although the genetic basis of mitral valve prolapse (MVP) has now been clearly established, the molecular and cellular mechanisms involved in the pathological processes associated to a specific mutation often remain to be determined. The FLNA gene (encoding Filamin A; FlnA) was the first gene associated to non-syndromic X-linked myxomatous valvular dystrophy, but the impacts of the mutations on its function remain un-elucidated. Here, using the first repeats (1-8) of FlnA as a bait in a yeast two-hybrid screen, we identified the tyrosine phosphatase PTPN12 (PTP-PEST) as a specific binding partner of this region of FlnA protein. In addition, using yeast two-hybrid trap assay pull down and co-immunoprecipitation experiments, we showed that the MVP-associated FlnA mutations (G288R, P637Q, H743P) abolished FlnA/PTPN12 interactions. PTPN12 is a key regulator of signaling pathways involved in cell-extracellular matrix (ECM) crosstalk, cellular responses to mechanical stress that involve integrins, focal adhesion transduction pathways, and actin cytoskeleton dynamics. Interestingly, we showed that the FlnA mutations impair the activation status of two PTPN12 substrates, the focal adhesion associated kinase Src, and the RhoA specific activating protein p190RhoGAP. Together, these data point to PTPN12/FlnA interaction and its weakening by FlnA mutations as a mechanism potentially involved in the physiopathology of FlnA-associated MVP.
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28
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Seppälä J, Tossavainen H, Rodic N, Permi P, Pentikäinen U, Ylänne J. Flexible Structure of Peptide-Bound Filamin A Mechanosensor Domain Pair 20-21. PLoS One 2015; 10:e0136969. [PMID: 26322797 PMCID: PMC4554727 DOI: 10.1371/journal.pone.0136969] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 08/12/2015] [Indexed: 11/18/2022] Open
Abstract
Filamins (FLNs) are large, multidomain actin cross-linking proteins with diverse functions. Besides regulating the actin cytoskeleton, they serve as important links between the extracellular matrix and the cytoskeleton by binding cell surface receptors, functioning as scaffolds for signaling proteins, and binding several other cytoskeletal proteins that regulate cell adhesion dynamics. Structurally, FLNs are formed of an amino terminal actin-binding domain followed by 24 immunoglobulin-like domains (IgFLNs). Recent studies have demonstrated that myosin-mediated contractile forces can reveal hidden protein binding sites in the domain pairs IgFLNa18–19 and 20–21, enabling FLNs to transduce mechanical signals in cells. The atomic structures of these mechanosensor domain pairs in the resting state are known, as well as the structures of individual IgFLN21 with ligand peptides. However, little experimental data is available on how interacting protein binding deforms the domain pair structures. Here, using small-angle x-ray scattering-based modelling, x-ray crystallography, and NMR, we show that the adaptor protein migfilin-derived peptide-bound structure of IgFLNa20–21 is flexible and adopts distinctive conformations depending on the presence or absence of the interacting peptide. The conformational changes reported here may be common for all peptides and may play a role in the mechanosensor function of the site.
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Affiliation(s)
- Jonne Seppälä
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
- * E-mail:
| | - Helena Tossavainen
- Program in Structural Biology and Biophysics, Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Nebojsa Rodic
- Program in Structural Biology and Biophysics, Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Perttu Permi
- Program in Structural Biology and Biophysics, Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Ulla Pentikäinen
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
| | - Jari Ylänne
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
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29
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Liu J, Das M, Yang J, Ithychanda SS, Yakubenko VP, Plow EF, Qin J. Structural mechanism of integrin inactivation by filamin. Nat Struct Mol Biol 2015; 22:383-9. [PMID: 25849143 PMCID: PMC4424056 DOI: 10.1038/nsmb.2999] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 03/05/2015] [Indexed: 12/15/2022]
Abstract
Activation of heterodimeric (αβ) integrin is crucial for regulating cell adhesion. Binding of talin to the cytoplasmic face of integrin activates the receptor, but how integrin is maintained in a resting state to counterbalance its activation has remained obscure. Here, we report the structure of the cytoplasmic domain of human integrin αIIbβ3 bound to its inhibitor, the immunoglobin repeat 21 of filamin A (FLNa-Ig21). The structure reveals an unexpected ternary complex in which FLNa-Ig21 not only binds to the C terminus of the integrin β3 cytoplasmic tail (CT), as previously predicted, but also engages N-terminal helices of αIIb and β3 CTs to stabilize an inter-CT clasp that helps restrain the integrin in a resting state. Combined with functional data, the structure reveals a new mechanism of filamin-mediated retention of inactive integrin, suggesting a new framework for understanding regulation of integrin activation and adhesion.
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Affiliation(s)
| | | | - Jun Yang
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Ave., Cleveland, Ohio, USA
| | - Sujay Subbayya Ithychanda
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Ave., Cleveland, Ohio, USA
| | - Valentin P. Yakubenko
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Ave., Cleveland, Ohio, USA
| | - Edward F Plow
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Ave., Cleveland, Ohio, USA
| | - Jun Qin
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Ave., Cleveland, Ohio, USA
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30
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Ithychanda SS, Fang X, Mohan ML, Zhu L, Tirupula KC, Naga Prasad SV, Wang YX, Karnik SS, Qin J. A mechanism of global shape-dependent recognition and phosphorylation of filamin by protein kinase A. J Biol Chem 2015; 290:8527-38. [PMID: 25666618 PMCID: PMC4375502 DOI: 10.1074/jbc.m114.633446] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 01/27/2015] [Indexed: 12/23/2022] Open
Abstract
Protein phosphorylation mediates essentially all aspects of cellular life. In humans, this is achieved by ∼500 kinases, each recognizing a specific consensus motif (CM) in the substrates. The majority of CMs are surface-exposed and are thought to be accessible to kinases for phosphorylation. Here we investigated the archetypical protein kinase A (PKA)-mediated phosphorylation of filamin, a major cytoskeletal protein that can adopt an autoinhibited conformation. Surprisingly, autoinhibited filamin is refractory to phosphorylation by PKA on a known Ser(2152) site despite its CM being exposed and the corresponding isolated peptide being readily phosphorylated. Structural analysis revealed that although the CM fits into the PKA active site its surrounding regions sterically clash with the kinase. However, upon ligand binding, filamin undergoes a conformational adjustment, allowing rapid phosphorylation on Ser(2152). These data uncover a novel ligand-induced conformational switch to trigger filamin phosphorylation. They further suggest a substrate shape-dependent filtering mechanism that channels specific exposed CM/kinase recognition in diverse signaling responses.
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Affiliation(s)
- Sujay Subbayya Ithychanda
- From the Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Xianyang Fang
- Protein-Nucleic Acid Interaction Section, Structural Biophysics Laboratory, NCI, National Institutes of Health, Frederick, Maryland 21702, and
| | - Maradumane L Mohan
- From the Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Liang Zhu
- From the Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195, Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | - Kalyan C Tirupula
- From the Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Sathyamangla V Naga Prasad
- From the Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Yun-Xing Wang
- Protein-Nucleic Acid Interaction Section, Structural Biophysics Laboratory, NCI, National Institutes of Health, Frederick, Maryland 21702, and
| | - Sadashiva S Karnik
- From the Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Jun Qin
- From the Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195, Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
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31
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Truong T, Shams H, Mofrad MRK. Mechanisms of integrin and filamin binding and their interplay with talin during early focal adhesion formation. Integr Biol (Camb) 2015; 7:1285-96. [DOI: 10.1039/c5ib00133a] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Mechanisms of the interplay among filamin, integrin and talin during early focal adhesion formation were explored using molecular dynamics simulations.
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Affiliation(s)
- Tiffany Truong
- Molecular Cell Biomechanics Laboratory
- Departments of Bioengineering and Mechanical Engineering
- University of California Berkeley
- Berkeley
- USA
| | - Hengameh Shams
- Molecular Cell Biomechanics Laboratory
- Departments of Bioengineering and Mechanical Engineering
- University of California Berkeley
- Berkeley
- USA
| | - Mohammad R. K. Mofrad
- Molecular Cell Biomechanics Laboratory
- Departments of Bioengineering and Mechanical Engineering
- University of California Berkeley
- Berkeley
- USA
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32
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Sethi R, Ylänne J. Small-angle X-ray scattering reveals compact domain-domain interactions in the N-terminal region of filamin C. PLoS One 2014; 9:e107457. [PMID: 25243668 PMCID: PMC4170960 DOI: 10.1371/journal.pone.0107457] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 08/18/2014] [Indexed: 12/30/2022] Open
Abstract
Filamins are multi-domain, actin cross-linking, and scaffolding proteins. In addition to the actin cross-linking function, filamins have a role in mechanosensor signaling. The mechanosensor function is mediated by domain-domain interaction in the C-terminal region of filamins. Recently, we have shown that there is a three-domain interaction module in the N-terminal region of filamins, where the neighboring domains stabilize the structure of the middle domain and thereby regulate its interaction with ligands. In this study, we have used small-angle X-ray scattering as a tool to screen for potential domain-domain interactions in the N-terminal region. We found evidence of four domain-domain interactions with varying flexibility. These results confirm our previous study showing that domains 3, 4, and 5 exist as a compact three domain module. In addition, we report interactions between domains 11-12 and 14-15, which are thus new candidate sites for mechanical regulation.
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Affiliation(s)
- Ritika Sethi
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
| | - Jari Ylänne
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
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33
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Documentation and localization of force-mediated filamin A domain perturbations in moving cells. Nat Commun 2014; 5:4656. [PMID: 25120197 PMCID: PMC4139033 DOI: 10.1038/ncomms5656] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 07/10/2014] [Indexed: 12/15/2022] Open
Abstract
Endogenously and externally generated mechanical forces influence diverse cellular activities, a phenomenon defined as mechanotransduction. Deformation of protein domains by application of stress, previously documented to alter macromolecular interactions in vitro, could mediate these effects. We engineered a photon-emitting system responsive to unfolding of two repeat domains of the actin filament (F-actin) crosslinker protein filamin A (FLNA) that binds multiple partners involved in cell signalling reactions and validated the system using F-actin networks subjected to myosin-based contraction. Expressed in cultured cells, the sensor-containing FLNA construct reproducibly reported FLNA domain unfolding strikingly localized to dynamic, actively protruding, leading cell edges. The unfolding signal depends upon coherence of F-actin-FLNA networks and is enhanced by stimulating cell contractility. The results establish protein domain distortion as a bona fide mechanism for mechanotransduction in vivo.
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34
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He H, Ding F, Li S, Chen H, Liu Z. Expression of migfilin is increased in esophageal cancer and represses the Akt-β-catenin activation. Am J Cancer Res 2014; 4:270-278. [PMID: 24959381 PMCID: PMC4065407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 04/11/2014] [Indexed: 06/03/2023] Open
Abstract
Cell adhesion proteins that connect each cell to neighboring cells and the extracellular matrix are an important determinant of cell morphology and metastasis. Migfilin is a member of LIM-containing protein family, mediated the linkage between cytoskeleton and focal adhesion through interacting with other proteins and involved in cell adhesion and motility. The present study used immunohistochemistry and Western blot analysis of migfilin in clinical specimens of esophageal squamous cell carcinoma (ESCC) to identify that the expression of migfilin was significantly upregulated in ESCC in concomitance with a nuclear-cytoplasm translocation compared to normal adjacent tissue. Alternately, using the published datasets we identified that the expression of β-catenin was upregulated in esophageal cancer cells with focal invasion, while inversely correlated with migfilin in esophageal cancer cell lines. We demonstrated that the reduced expression of β-catenin by migfilin was through the inhibition of Akt activation. In conclusion, these results illustrated that migfilin upregulated in ESCCs and repressed β-catenin in an Akt-GSK3β signaling dependent manner.
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Affiliation(s)
- Huan He
- The State Key Laboratory of Molecular Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100021, China
| | - Fang Ding
- The State Key Laboratory of Molecular Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100021, China
| | - Sheng Li
- The State Key Laboratory of Molecular Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100021, China
| | - Hongyan Chen
- The State Key Laboratory of Molecular Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100021, China
| | - Zhihua Liu
- The State Key Laboratory of Molecular Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100021, China
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35
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Sethi R, Seppälä J, Tossavainen H, Ylilauri M, Ruskamo S, Pentikäinen OT, Pentikäinen U, Permi P, Ylänne J. A novel structural unit in the N-terminal region of filamins. J Biol Chem 2014; 289:8588-98. [PMID: 24469451 DOI: 10.1074/jbc.m113.537456] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Immunoglobulin-like (Ig) domains are a widely expanded superfamily that act as interaction motifs or as structural spacers in multidomain proteins. Vertebrate filamins (FLNs), which are multifunctional actin-binding proteins, consist of 24 Ig domains. We have recently discovered that in the C-terminal rod 2 region of FLN, Ig domains interact with each other forming functional domain pairs, where the interaction with signaling and transmembrane proteins is mechanically regulated by weak actomyosin contraction forces. Here, we investigated if there are similar inter-domain interactions around domain 4 in the N-terminal rod 1 region of FLN. Protein crystal structures revealed a new type of domain organization between domains 3, 4, and 5. In this module, domains 4 and 5 interact rather tightly, whereas domain 3 has a partially flexible interface with domain 4. NMR peptide titration experiments showed that within the three-domain module, domain 4 is capable for interaction with a peptide derived from platelet glycoprotein Ib. Crystal structures of FLN domains 4 and 5 in complex with the peptide revealed a typical β sheet augmentation interaction observed for many FLN ligands. Domain 5 was found to stabilize domain 4, and this could provide a mechanism for the regulation of domain 4 interactions.
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Affiliation(s)
- Ritika Sethi
- From the Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, P. O. Box 35, Survontie 9, 40014 Jyväskylä
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Jahed Z, Shams H, Mehrbod M, Mofrad MRK. Mechanotransduction pathways linking the extracellular matrix to the nucleus. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 310:171-220. [PMID: 24725427 DOI: 10.1016/b978-0-12-800180-6.00005-0] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Cells contain several mechanosensing components that transduce mechanical signals into biochemical cascades. During cell-ECM adhesion, a complex network of molecules mechanically couples the extracellular matrix (ECM), cytoskeleton, and nucleoskeleton. The network comprises transmembrane receptor proteins and focal adhesions, which link the ECM and cytoskeleton. Additionally, recently identified protein complexes extend this linkage to the nucleus by linking the cytoskeleton and the nucleoskeleton. Despite numerous studies in this field, due to the complexity of this network, our knowledge of the mechanisms of cell-ECM adhesion at the molecular level remains remarkably incomplete. Herein, we present a review of the structures of key molecules involved in cell-ECM adhesion, along with an evaluation of their predicted roles in mechanical sensing. Additionally, specific binding events prompted by force-induced conformational changes of each molecule are discussed. Finally, we propose a model for the biomechanical events prominent in cell-ECM adhesion.
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Affiliation(s)
- Zeinab Jahed
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California at Berkeley, Berkeley, California, USA
| | - Hengameh Shams
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California at Berkeley, Berkeley, California, USA
| | - Mehrdad Mehrbod
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California at Berkeley, Berkeley, California, USA
| | - Mohammad R K Mofrad
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California at Berkeley, Berkeley, California, USA.
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Valvular dystrophy associated filamin A mutations reveal a new role of its first repeats in small-GTPase regulation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1843:234-44. [PMID: 24200678 DOI: 10.1016/j.bbamcr.2013.10.022] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 10/26/2013] [Accepted: 10/28/2013] [Indexed: 11/23/2022]
Abstract
Filamin A (FlnA) is a ubiquitous actin binding protein which anchors various transmembrane proteins to the cell cytoskeleton and provides a scaffold to many cytoplasmic signaling proteins involved in actin cytoskeleton remodeling in response to mechanical stress and cytokines stimulation. Although the vast majority of FlnA binding partners interact with the carboxy-terminal immunoglobulin like (Igl) repeats of FlnA, little is known on the role of the amino-N-terminal repeats. Here, using cardiac mitral valvular dystrophy associated FlnA-G288R and P637Q mutations located in the N-terminal Igl repeat 1 and 4 respectively as a model, we identified a new role of FlnA N-terminal repeats in small Rho-GTPases regulation. Using FlnA-deficient melanoma and HT1080 cell lines as expression systems we showed that FlnA mutations reduce cell spreading and migration capacities. Furthermore, we defined a signaling network in which FlnA mutations alter the balance between RhoA and Rac1 GTPases activities in favor of RhoA and provided evidences for a role of the Rac1 specific GTPase activating protein FilGAP in this process. Together our work ascribed a new role to the N-terminal repeats of FlnA in Small GTPases regulation and supports a conceptual framework for the role of FlnA mutations in cardiac valve diseases centered around signaling molecules regulating cellular actin cytoskeleton in response to mechanical stress.
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Gupta N, Li W, Willard B, Silverstein RL, McIntyre TM. Proteasome proteolysis supports stimulated platelet function and thrombosis. Arterioscler Thromb Vasc Biol 2013; 34:160-8. [PMID: 24177323 DOI: 10.1161/atvbaha.113.302116] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE Proteasome inhibitors used in the treatment of hematologic cancers also reduce thrombosis. Whether the proteasome participates in platelet activation or function is unclear because little is known of the proteasome in these terminally differentiated cells. APPROACH AND RESULTS Platelets displayed all 3 primary proteasome protease activities, which MG132 and bortezomib (Velcade) inhibited. Proteasome substrates are marked by ubiquitin, and platelets contained a functional ubiquitination system that modified the proteome by monoubiquitination and polyubiquitination. Systemic MG132 strongly suppressed the formation of occlusive, platelet-rich thrombi in FeCl3-damaged carotid arteries. Transfusion of platelets treated ex vivo with MG132 and washed before transfusion into thrombocytopenic mice also reduced carotid artery thrombosis. Proteasome inhibition reduced platelet aggregation by low thrombin concentrations and ristocetin-stimulated agglutination through the glycoprotein Ib-IX-V complex. This receptor was not appropriately internalized after proteasome inhibition in stimulated platelets, and spreading and clot retraction after MG132 exposure also were decreased. The effects of proteasome inhibitors were not confined to a single receptor as MG132 suppressed thrombin-stimulated, ADP-stimulated, and lipopolysaccharide-stimulated microparticle shedding. Proteasome inhibition increased ubiquitin decoration of cytoplasmic proteins, including the cytoskeletal proteins Filamin A and Talin-1. Mass spectrometry revealed a single MG132-sensitive tryptic cleavage after R1745 in an extended Filamin A loop, which would separate its actin-binding domain from its carboxy terminal glycoprotein Ibα-binding domain. CONCLUSIONS Platelets contain a ubiquitin/proteasome system that marks cytoskeletal proteins for proteolytic modification to promote productive platelet-platelet and platelet-wall interactions.
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Affiliation(s)
- Nilaksh Gupta
- From the Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland, OH (N.G., W.L., B.W., R.L.S., T.M.M.); and Department of Biological Geological and Environmental Sciences, Cleveland State University, Cleveland, OH (N.G., T.M.M.)
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Zakaria R, Lamsoul I, Uttenweiler-Joseph S, Erard M, Monsarrat B, Burlet-Schiltz O, Moog-Lutz C, Lutz PG. Phosphorylation of serine 323 of ASB2α is pivotal for the targeting of filamin A to degradation. Cell Signal 2013; 25:2823-30. [PMID: 24044920 DOI: 10.1016/j.cellsig.2013.09.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Accepted: 09/06/2013] [Indexed: 10/26/2022]
Abstract
ASB proteins are the specificity subunits of cullin5-RING E3 ubiquitin ligases (CRL5) that play roles in ubiquitin-mediated protein degradation. However, how their activity is regulated remains poorly understood. Here, we unravel a novel mechanism of regulation of a CRL5 through phosphorylation of its specificity subunit ASB2α. Indeed, using mass spectrometry, we showed for the first time that ASB2α is phosphorylated and that phosphorylation of serine-323 (Ser-323) of ASB2α is crucial for the targeting of the actin-binding protein filamin A (FLNa) to degradation. Mutation of ASB2α Ser-323 to Ala had no effect on intrinsic E3 ubiquitin ligase activity of ASB2α but abolished the ability of ASB2α to induce degradation of FLNa. In contrast, the ASB2α Ser-323 to Asp phosphomimetic mutant induced acute degradation of FLNa. Moreover, inhibition of the extracellular signal-regulated kinases 1 and 2 (Erk1/2) activity reduced ASB2α-mediated FLNa degradation. We further showed that the subcellular localization of ASB2α to actin-rich structures is dependent on ASB2α Ser-323 phosphorylation and propose that the interaction with FLNa depends on the electrostatic potential redistribution induced by the Ser-323 phosphate group. Taken together, these data unravel an important mechanism by which ASB2α-mediated FLNa degradation can be regulated.
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Affiliation(s)
- Rim Zakaria
- CNRS; IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne BP 64182, F-31077 Toulouse, France; Université de Toulouse, UPS, IPBS, F-31077 Toulouse, France
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Ylilauri M, Pentikäinen OT. MMGBSA as a tool to understand the binding affinities of filamin-peptide interactions. J Chem Inf Model 2013; 53:2626-33. [PMID: 23988151 DOI: 10.1021/ci4002475] [Citation(s) in RCA: 192] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Filamins (FLN) are large dimeric proteins that cross-link actin and work as important scaffolds in human cells. FLNs consist of an N-terminal actin-binding domain followed by 24 immunoglobulin-like domains (FLN1-24). FLN domains are divided into four subgroups based on their amino acid sequences. One of these subgroups, including domains 4, 9, 12, 17, 19, 21, and 23, shares a similar ligand-binding site between the β strands C and D. Several proteins, such as integrins β2 and β7, glycoprotein Ibα (GPIbα), and migfilin, have been shown to bind to this site. Here, we computationally estimated the binding free energies of filamin A (FLNa) subunits with bound peptides using the molecular mechanics-generalized Born surface area (MMGBSA) method. The obtained computational results correlated well with the experimental data, and they ranked efficiently both the binding of one ligand to all used FLNa-domains and the binding of all used ligands to FLNa21. Furthermore, the steered molecular dynamics (SMD) simulations pinpointed the binding hot spots for these complexes. These results demonstrate that molecular dynamics combined with free energy calculations are applicable to estimating the energetics of protein-protein interactions and can be used to direct the development of novel FLN function modulators.
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Affiliation(s)
- Mikko Ylilauri
- Computational Bioscience Laboratory, Department of Biological and Environmental Science & Nanoscience Center, University of Jyväskylä , P.O. Box 35, Jyväskylä FI-40014, Finland
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Wang R, Bi J, Ampah KK, Zhang C, Li Z, Jiao Y, Wang X, Ba X, Zeng X. Lipid raft regulates the initial spreading of melanoma A375 cells by modulating β1 integrin clustering. Int J Biochem Cell Biol 2013; 45:1679-89. [PMID: 23665237 DOI: 10.1016/j.biocel.2013.04.031] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2012] [Revised: 04/28/2013] [Accepted: 04/29/2013] [Indexed: 01/16/2023]
Abstract
Cell adhesion and spreading require integrins-mediated cell-extracellular matrix interaction. Integrins function through binding to extracellular matrix and subsequent clustering to initiate focal adhesion formation and actin cytoskeleton rearrangement. Lipid raft, a liquid ordered plasma membrane microdomain, has been reported to play major roles in membrane motility by regulating cell surface receptor function. Here, we identified that lipid raft integrity was required for β1 integrin-mediated initial spreading of melanoma A375 cells on fibronectin. We found that lipid raft disruption with methyl-β-cyclodextrin led to the inability of focal adhesion formation and actin cytoskeleton rearrangement by preventing β1 integrin clustering. Furthermore, we explored the possible mechanism by which lipid raft regulates β1 integrin clustering and demonstrated that intact lipid raft could recruit and modify some adaptor proteins, such as talin, α-actinin, vinculin, paxillin and FAK. Lipid raft could regulate the location of these proteins in lipid raft fractions and facilitate their binding to β1 integrin, which may be crucial for β1 integrin clustering. We also showed that lipid raft disruption impaired A375 cell migration in both transwell and wound healing models. Together, these findings provide a new insight for the relationship between lipid raft and the regulation of integrins.
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Affiliation(s)
- Ruifei Wang
- Institute of Genetics and Cytology, Northeast Normal University, Changchun 130024, China
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Abstract
Integrins are heterodimeric cell adhesion molecules that are important in many biological functions, such as cell migration, proliferation, differentiation, and survival. They can transmit bi-directional signals across the plasma membrane. Inside-out activating signal from some cell surface receptors bound with soluble agonists triggers integrins conformational change leading to high affinity for extracellular ligands. Then binding of ligands to integrins results in outside-in signaling, leading to formation of focal adhesion complex at the integrin cytoplasmic tail and activation of downstream signal pathways. This bi-directional signaling is essential for rapid response of cell to surrounding environmental changes. During this process, the conformational change of integrin extracellular and transmembrane/cytoplasmic domains is particularly important. In this review, we will summarize recent progress in both inside-out and outside-in signaling with specific focus on the mechanism how integrins transmit bi-directional signals through transmembrane/cytoplasmic domains.
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Affiliation(s)
- Ping Hu
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803, USA
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43
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Dynamic force sensing of filamin revealed in single-molecule experiments. Proc Natl Acad Sci U S A 2012; 109:19679-84. [PMID: 23150587 DOI: 10.1073/pnas.1211274109] [Citation(s) in RCA: 124] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Mechanical forces are important signals for cell response and development, but detailed molecular mechanisms of force sensing are largely unexplored. The cytoskeletal protein filamin is a key connecting element between the cytoskeleton and transmembrane complexes such as integrins or the von Willebrand receptor glycoprotein Ib. Here, we show using single-molecule mechanical measurements that the recently reported Ig domain pair 20-21 of human filamin A acts as an autoinhibited force-activatable mechanosensor. We developed a mechanical single-molecule competition assay that allows online observation of binding events of target peptides in solution to the strained domain pair. We find that filamin force sensing is a highly dynamic process occurring in rapid equilibrium that increases the affinity to the target peptides by up to a factor of 17 between 2 and 5 pN. The equilibrium mechanism we find here can offer a general scheme for cellular force sensing.
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Peña E, Arderiu G, Badimon L. Subcellular localization of tissue factor and human coronary artery smooth muscle cell migration. J Thromb Haemost 2012; 10:2373-82. [PMID: 22938499 DOI: 10.1111/j.1538-7836.2012.04910.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND Tissue factor (TF) is the most relevant physiological trigger of thrombosis. Additionally TF is a transmembrane receptor with cell signaling functions. OBJECTIVES The aim of this study was to investigate TF subcellular localization, function and signaling in human coronary artery smooth muscle cell migration. METHODS Coronary arteries and primary cultures of vascular smooth muscle cells (HVSMC) were obtained from human explanted hearts. Wound repair and Boyden chamber assays were used to measure migration in vitro. TF-pro-coagulant activity (TF-PCA) was measured in extracted cellular membranes. Analysis of TF distribution was performed by confocal microscopy. A nucleofector device was used for TF and protease activated receptor 2 (PAR2) silencing. mRNA levels were analyzed by RT-PCR. RESULTS In migrating HVSMC TF translocates to the leading edge of the cells showing an intense patch-like staining in the lamellipodia. In the migrating front TF colocalizes with filamin (FLN) in the polarized lipid rafts. TF-PCA was increased in migrating cells. Silencing of the TF gene inhibits RSK-induced FLN-Ser-2152 phosphorylation, down-regulates CDC42, RhoA, and Rac1 protein expression and significantly inhibits cell migration. Silencing PAR2 also inhibits cell migration; however, silencing both TF and PAR2 induces a significantly higher effect on migration. Smooth muscle cells expressing TF have been identified in non-lipid-rich human coronary artery atherosclerotic plaques. CONCLUSIONS TF translocates to the cell front in association with cytoskeleton proteins and regulates HVSMC migration by mechanisms dependent and independent of factor (F)VIIa/PAR2. These results extend the functional role of TF to smooth muscle cell trafficking in vessel wall remodeling.
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Affiliation(s)
- E Peña
- Cardiovascular Research Center, CSIC-ICCC, Hospital de la Santa Creu i Sant Pau, IIB-Sant Pau, Barcelona CIBEROBN-Pathophysiology of Obesity and Nutrition, Barcelona Cardiovascular Research Chair, UAB, Barcelona, Spain
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Sawyer GM, Sutherland-Smith AJ. Crystal structure of the filamin N-terminal region reveals a hinge between the actin binding and first repeat domains. J Mol Biol 2012; 424:240-7. [PMID: 23036857 DOI: 10.1016/j.jmb.2012.09.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Accepted: 09/20/2012] [Indexed: 11/15/2022]
Abstract
The filamin proteins cross-link F-actin and interact with protein partners to integrate both extracellular and intracellular signalling events with the cytoskeleton and to provide mechanoprotection and sensing to cells. The filamins are large, flexible, multi-domain homodimers with the interactions between domains important for protein function. The crystal structure of the N-terminal region of filamin B, containing the actin binding domain (ABD) and the first filamin repeat (FR1) domain, reveals an extended two-domain conformation with no interaction between the ABD and FR1 other than the connecting linker region. The two FLNB347 structures in the crystallographic asymmetric unit exhibit differing relative domain orientations providing the first high-resolution structural characterisation of a filamin inter-domain conformational change. The structure reveals a new hinge in the linker region between ABD and FR1 that is ideally positioned to orient the ABD for actin binding and adds to the previously described hinge regions, hinge 1 (between repeats 15 and 16) and hinge 2 (repeats 23 and 24), providing an additional mechanism by which filamin can exhibit inter-domain flexibility. The extended structure, with the absence of interactions between the domains, implies that any conformational rearrangements required for actin binding by the ABD, as observed for homologous proteins, can freely occur without being influenced by FR1. The ABD retains its previously observed compact conformation. FR1 exhibits a filamin immunoglobulin-like domain fold with a closed C-D β-strand groove, in contrast to filamin repeats that bind protein partners with this region of the domain surface.
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Affiliation(s)
- Gregory M Sawyer
- Institute of Molecular Biosciences, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand
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Lee HJ, Hota PK, Chugha P, Guo H, Miao H, Zhang L, Kim SJ, Stetzik L, Wang BC, Buck M. NMR structure of a heterodimeric SAM:SAM complex: characterization and manipulation of EphA2 binding reveal new cellular functions of SHIP2. Structure 2012; 20:41-55. [PMID: 22244754 DOI: 10.1016/j.str.2011.11.013] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Revised: 11/08/2011] [Accepted: 11/10/2011] [Indexed: 02/06/2023]
Abstract
The sterile alpha motif (SAM) for protein-protein interactions is encountered in over 200 proteins, but the structural basis for its interactions is just becoming clear. Here we solved the structure of the EphA2-SHIP2 SAM:SAM heterodimeric complex by use of NMR restraints from chemical shift perturbations, NOE and RDC experiments. Specific contacts between the protein surfaces differ significantly from a previous model and other SAM:SAM complexes. Molecular dynamics and docking simulations indicate fluctuations in the complex toward alternate, higher energy conformations. The interface suggests that EphA family members bind to SHIP2 SAM, whereas EphB members may not; correspondingly, we demonstrate binding of EphA1, but not of EphB2, to SHIP2. A variant of EphB2 SAM was designed that binds SHIP2. Functional characterization of a mutant EphA2 compromised in SHIP2 binding reveals two previously unrecognized functions of SHIP2 in suppressing ligand-induced activation of EphA2 and in promoting receptor coordinated chemotactic cell migration.
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Affiliation(s)
- Hyeong J Lee
- Department of Physiology and Biophysics, MetroHealth, Cleveland, OH 44109, USA
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47
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Light S, Sagit R, Ithychanda SS, Qin J, Elofsson A. The evolution of filamin-a protein domain repeat perspective. J Struct Biol 2012; 179:289-98. [PMID: 22414427 DOI: 10.1016/j.jsb.2012.02.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Revised: 02/03/2012] [Accepted: 02/15/2012] [Indexed: 10/28/2022]
Abstract
Particularly in higher eukaryotes, some protein domains are found in tandem repeats, performing broad functions often related to cellular organization. For instance, the eukaryotic protein filamin interacts with many proteins and is crucial for the cytoskeleton. The functional properties of long repeat domains are governed by the specific properties of each individual domain as well as by the repeat copy number. To provide better understanding of the evolutionary and functional history of repeating domains, we investigated the mode of evolution of the filamin domain in some detail. Among the domains that are common in long repeat proteins, sushi and spectrin domains evolve primarily through cassette tandem duplications while scavenger and immunoglobulin repeats appear to evolve through clustered tandem duplications. Additionally, immunoglobulin and filamin repeats exhibit a unique pattern where every other domain shows high sequence similarity. This pattern may be the result of tandem duplications, serve to avert aggregation between adjacent domains or it is the result of functional constraints. In filamin, our studies confirm the presence of interspersed integrin binding domains in vertebrates, while invertebrates exhibit more varied patterns, including more clustered integrin binding domains. The most notable case is leech filamin, which contains a 20 repeat expansion and exhibits unique dimerization topology. Clearly, invertebrate filamins are varied and contain examples of similar adjacent integrin-binding domains. Given that invertebrate integrin shows more similarity to the weaker filamin binder, integrin β3, it is possible that the distance between integrin-binding domains is not as crucial for invertebrate filamins as for vertebrates.
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Affiliation(s)
- Sara Light
- Center for Biomembrane Research, Department of Biochemistry and Biophysics, Science for Life Laboratory, Bioinformatics Infrastructure for Life Sciences, Stockholm University, SE-17121 Solna, Sweden
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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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Burgess JK, Weckmann M. Matrikines and the lungs. Pharmacol Ther 2012; 134:317-37. [PMID: 22366287 DOI: 10.1016/j.pharmthera.2012.02.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Accepted: 02/03/2012] [Indexed: 01/09/2023]
Abstract
The extracellular matrix is a complex network of fibrous and nonfibrous molecules that not only provide structure to the lung but also interact with and regulate the behaviour of the cells which it surrounds. Recently it has been recognised that components of the extracellular matrix proteins are released, often through the action of endogenous proteases, and these fragments are termed matrikines. Matrikines have biological activities, independent of their role within the extracellular matrix structure, which may play important roles in the lung in health and disease pathology. Integrins are the primary cell surface receptors, characterised to date, which are used by the matrikines to exert their effects on cells. However, evidence is emerging for the need for co-factors and other receptors for the matrikines to exert their effects on cells. The potential for matrikines, and peptides derived from these extracellular matrix protein fragments, as therapeutic agents has recently been recognised. The natural role of these matrikines (including inhibitors of angiogenesis and possibly inflammation) make them ideal targets to mimic as therapies. A number of these peptides have been taken forward into clinical trials. The focus of this review will be to summarise our current understanding of the role, and potential for highly relevant actions, of matrikines in lung health and disease.
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Affiliation(s)
- Janette K Burgess
- Cell Biology, Woolcock Institute of Medical Research, Sydney, NSW, Australia.
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Adams M, Simms RJ, Abdelhamed Z, Dawe HR, Szymanska K, Logan CV, Wheway G, Pitt E, Gull K, Knowles MA, Blair E, Cross SH, Sayer JA, Johnson CA. A meckelin-filamin A interaction mediates ciliogenesis. Hum Mol Genet 2011; 21:1272-86. [PMID: 22121117 DOI: 10.1093/hmg/ddr557] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
MKS3, encoding the transmembrane receptor meckelin, is mutated in Meckel-Gruber syndrome (MKS), an autosomal-recessive ciliopathy. Meckelin localizes to the primary cilium, basal body and elsewhere within the cell. Here, we found that the cytoplasmic domain of meckelin directly interacts with the actin-binding protein filamin A, potentially at the apical cell surface associated with the basal body. Mutations in FLNA, the gene for filamin A, cause periventricular heterotopias. We identified a single consanguineous patient with an MKS-like ciliopathy that presented with both MKS and cerebellar heterotopia, caused by an unusual in-frame deletion mutation in the meckelin C-terminus at the region of interaction with filamin A. We modelled this mutation and found it to abrogate the meckelin-filamin A interaction. Furthermore, we found that loss of filamin A by siRNA knockdown, in patient cells, and in tissues from Flna(Dilp2) null mouse embryos results in cellular phenotypes identical to those caused by meckelin loss, namely basal body positioning and ciliogenesis defects. In addition, morpholino knockdown of flna in zebrafish embryos significantly increases the frequency of dysmorphology and severity of ciliopathy developmental defects caused by mks3 knockdown. Our results suggest that meckelin forms a functional complex with filamin A that is disrupted in MKS and causes defects in neuronal migration and Wnt signalling. Furthermore, filamin A has a crucial role in the normal processes of ciliogenesis and basal body positioning. Concurrent with these processes, the meckelin-filamin A signalling axis may be a key regulator in maintaining correct, normal levels of Wnt signalling.
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Affiliation(s)
- Matthew Adams
- Ciliopathy Research Group, Section of Ophthalmology and Neurosciences, Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, UK
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