Search results for "Filamins"
showing 10 items of 31 documents
Skeletal Dysplasia Mutations Effect on Human Filamins’ Structure and Mechanosensing
2016
AbstractCells’ 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 mo…
Association of Left Ventricular Systolic Dysfunction Among Carriers of Truncating Variants in Filamin C With Frequent Ventricular Arrhythmia and End-…
2021
Importance: Truncating variants in the gene encoding filamin C (FLNCtv) are associated with arrhythmogenic and dilated cardiomyopathies with a reportedly high risk of ventricular arrhythmia.Objective: To determine the frequency of and risk factors associated with adverse events among FLNCtv carriers compared with individuals carrying TTN truncating variants (TTNtv).Design, Setting, and Participants: This cohort study recruited 167 consecutive FLNCtv carriers and a control cohort of 244 patients with TTNtv matched for left ventricular ejection fraction (LVEF) from 19 European cardiomyopathy referral units between 1990 and 2018. Data analyses were conducted between June and October, 2020.Main…
Filopodia-like actin cables position nuclei in association with perinuclear actin in Drosophila nurse cells
2013
Summary Controlling the position of the nucleus is vital for a number of cellular processes from yeast to humans. In Drosophila nurse cells, nuclear positioning is crucial during dumping, when nurse cells contract and expel their contents into the oocyte. We provide evidence that in nurse cells, continuous filopodia-like actin cables, growing from the plasma membrane and extending to the nucleus, achieve nuclear positioning. These actin cables move nuclei away from ring canals. When nurse cells contract, actin cables associate laterally with the nuclei, in some cases inducing nuclear turning so that actin cables become partially wound around the nuclei. Our data suggest that a perinuclear a…
Atomic Structures of Two Novel Immunoglobulin-like Domain Pairs in the Actin Cross-linking Protein Filamin
2009
Filamins are actin filament cross-linking proteins composed of an N-terminal actin-binding domain and 24 immunoglobulin-like domains (IgFLNs). Filamins interact with numerous proteins, including the cytoplasmic domains of plasma membrane signaling and cell adhesion receptors. Thereby filamins mechanically and functionally link the cell membrane to the cytoskeleton. Most of the interactions have been mapped to the C-terminal IgFLNs 16–24. Similarly, as with the previously known compact domain pair of IgFLNa20–21, the two-domain fragments IgFLNa16–17 and IgFLNa18–19 were more compact in small angle x-ray scattering analysis than would be expected for two independent domains. Solution state NM…
RNA sequencing-based transcriptome profiling of cardiac tissue Implicados novela putative disease mechanisms in FLNC-associated arrhythmogenic cardio…
2020
Arrhythmogenic cardiomyopathy (ACM) encompasses a group of inherited cardiomyopathies including arrhythmogenic right ventricular cardiomyopathy (ARVC) whose molecular disease mechanism is associated with dysregulation of the canonical WNT signalling pathway. Recent evidence indicates that ARVC and ACM caused by pathogenic variants in the FLNC gene encoding filamin C, a major cardiac structural protein, may have different molecular mechanisms of pathogenesis. We sought to identify dysregulated biological pathways in FLNC-associated ACM. RNA was extracted from seven paraffin-embedded left ventricular tissue samples from deceased ACM patients carrying FLNC variants and sequenced. Transcript le…
Non-syndromic Mitral Valve Dysplasia Mutation Changes the Force Resilience and Interaction of Human Filamin A
2018
International audience; 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 signi…
Dynamic force sensing of filamin revealed in single-molecule experiments
2012
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 fi…
Model of a six immunoglobulin-like domain fragment of filamin A (16-21) built using residual dipolar couplings.
2012
Filamins are actin-binding proteins that participate in a wide range of cell functions, including cell morphology, locomotion, membrane protein localization, and intracellular signaling. The three filamin isoforms found in humans, filamins A, B, and C, are highly homologous, and their roles are partly complementary. In addition to actin, filamins interact with dozens of other proteins that have roles as membrane receptors and channels, enzymes, signaling intermediates, and transcription factors. Filamins are composed of an N-terminal actin-binding domain and 24 filamin-type immunoglobulin-like domains (FLN) that form tail-to-tail dimers with their C-terminal FLN domain. Many of the filamin …
Molecular basis of filamin a-filGAP interaction and its impairment in congenital disorders associated with filamin a mutations
2008
Background Mutations in filamin A (FLNa), an essential cytoskeletal protein with multiple binding partners, cause developmental anomalies in humans. Methodology/Principal Findings We determined the structure of the 23rd Ig repeat of FLNa (IgFLNa23) that interacts with FilGAP, a Rac-specific GTPase-activating protein and regulator of cell polarity and movement, and the effect of the three disease-related mutations on this interaction. A combination of NMR structural analysis and in silico modeling revealed the structural interface details between the C and D β-strands of the IgFLNa23 and the C-terminal 32 residues of FilGAP. Mutagenesis of the predicted key interface residues confirmed the b…
MMGBSA As a Tool To Understand the Binding Affinities of Filamin–Peptide Interactions
2013
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 mechan…