Search results for "Microfilament"
showing 10 items of 109 documents
The C-terminal rod 2 fragment of filamin A forms a compact structure that can be extended
2012
Filamins are large proteins that cross-link actin filaments and connect to other cellular components. The C-terminal rod 2 region of FLNa (filamin A) mediates dimerization and interacts with several transmembrane receptors and intracellular signalling adaptors. SAXS (small-angle X-ray scattering) experiments were used to make a model of a six immunoglobulin-like domain fragment of the FLNa rod 2 (domains 16–21). This fragment had a surprising three-branched structural arrangement, where each branch was made of a tightly packed two-domain pair. Peptides derived from transmembrane receptors and intracellular signalling proteins induced a more open structure of the six domain fragment. Mutagen…
FSHD muscular dystrophy region gene 1 binds Suv4-20h1 histone methyltransferase and impairs myogenesis.
2013
Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant myopathy with a strong epigenetic component. It is associated with deletion of a macrosatellite repeat leading to over-expression of the nearby genes. Among them, we focused on FSHD region gene 1 (FRG1) since its over-expression in mice, Xenopus laevis and Caenorhabditis elegans, leads to muscular dystrophy-like defects, suggesting that FRG1 plays a relevant role in muscle biology. Here we show that, when over-expressed, FRG1 binds and interferes with the activity of the histone methyltransferase Suv4-20h1 both in mammals and Drosophila. Accordingly, FRG1 over-expression or Suv4-20h1 knockdown inhibits myogenesis. Moreov…
Genome-wide association study identifies five loci associated with lung function
2009
Pulmonary function measures are heritable traits that predict morbidity and mortality and define chronic obstructive pulmonary disease (COPD). We tested genome-wide association with forced expiratory volume in 1 s (FEV(1)) and the ratio of FEV(1) to forced vital capacity (FVC) in the SpiroMeta consortium (n = 20,288 individuals of European ancestry). We conducted a meta-analysis of top signals with data from direct genotyping (n < or = 32,184 additional individuals) and in silico summary association data from the CHARGE Consortium (n = 21,209) and the Health 2000 survey (n < or = 883). We confirmed the reported locus at 4q31 and identified associations with FEV(1) or FEV(1)/FVC and co…
Synaptopodin regulates denervation-induced homeostatic synaptic plasticity
2013
Synaptopodin (SP) is a marker and essential component of the spine apparatus (SA), an enigmatic cellular organelle composed of stacked smooth endoplasmic reticulum that has been linked to synaptic plasticity. However, SP/SA-mediated synaptic plasticity remains incompletely understood. To study the role of SP/SA in homeostatic synaptic plasticity we here used denervation-induced synaptic scaling of mouse dentate granule cells as a model system. This form of plasticity is of considerable interest in the context of neurological diseases that are associated with the loss of neurons and subsequent denervation of connected brain regions. In entorhino-hippocampal slice cultures prepared from SP-de…
Immunohistochemical study of correlation between histologic subtype and expression of epithelial-mesenchymal transition-related proteins in synovial …
2011
Context.—Synovial sarcomas are mesenchymal tumors with epithelial nature and comprise biphasic and monophasic fibrous subtypes. However, factors determining epithelial or spindle cell differentiation are still unexplored. Aberrant epithelial-mesenchymal transition has been implicated in the pathogenesis of diverse human malignancies.Objective.—To analyze the correlation between cellular phenotype and expression of proteins associated with different epithelial-mesenchymal transition-related pathways.Design.—Immunohistochemical analysis of E-cadherin, Snail, Slug, and dysadherin, components of the Wnt/wingless and PI3K/Akt pathways, was performed on 14 biphasic and 27 monophasic fibrous tumor…
Villin: a cytoskeletal protein and a differentiation marker expressed in some human adenocarcinomas.
1987
We studied the expression of villin, a microfilament-associated, actin-binding protein typical of brush-border microvilli, in a variety of human carcinomas by applying immunofluorescence microscopy to frozen sections and immunoblotting methods to tissue extracts using a rabbit antiserum and a monoclonal antibody specific for villin. All of the 24 primary and metastatic colorectal adenocarcinomas tested were uniformly and strongly positive for villin, with the immunocytochemical labeling concentrated at the luminal cell margin. In poorly differentiated tumor areas, rudimentary tubules were stained. All of the six tubular adenocarcinomas of the stomach studied as well as two adenocarcinomas o…
Filamin C accumulation is a strong but nonspecific immunohistochemical marker of core formation in muscle.
2002
Filamin C is the muscle isoform of a group of large actin-crosslinking proteins. On the one hand, filamin C is associated with the Z-disk of the myofibrillar apparatus and binds to myotilin; on the other hand, it interacts with the sarcoglycan complex at the sarcolemma. Filamin C may be involved in reorganizing the cytoskeleton in response to signalling events and in muscle it may, in addition, fulfill structural functions at the Z-disk. An examination of biopsies from patients with multi-minicore myopathy, central core myopathy and neurogenic target fibers with core-like target formations (TF) revealed strong reactivity of all the cores and target formations with two different anti-filamin…
Cell Cycle in Potentially Dedifferentiating Cereal Mesophyll Protoplasts Cultured in vitro II. Behaviour of the Cytoskeleton
1993
Summary Following up on the recent finding that mesophyll protoplasts of wheat and oats were able to reenter the cell cycle when cultured in vitro , the behaviour of the cytoskeleton was studied. The aim was to elucidate whether changes in the cytoskeletal patterns correlate with the abnormal progression through the cycle observed previously. Protoplasts freshly isolated from mature mesophyll tissue (type B) exhibited very few, fragmented microtubules, whereas mesophyll protoplasts isolated from immature leaf tissue (type A) showed an abundant network fo microtubules. Type B protoplasts of wheat, which were able to reenter but recalcitrant to complete S-phase, failed to reestablish a microt…
Contribution of molecular analyses in diagnosing Marfan syndrome and type I fibrillinopathies: an international study of 1009 probands.
2008
International audience; BACKGROUND: The diagnosis of Marfan syndrome (MFS) is usually initially based on clinical criteria according to the number of major and minor systems affected following international nosology. The number of FBN1 mutation carriers, at risk of aortic complications who would not be properly diagnosed based only on clinical grounds, is of growing importance owing to the increased availability of molecular screening. The aim of the study was to identify patients who should be considered for FBN1 mutation screening. METHODS: Our international series included 1009 probands with a known FBN1 mutation. Patients were classified as either fulfilling or not fulfilling "clinical"…
B-Raf Acts via the ROCKII/LIMK/Cofilin Pathway To Maintain Actin Stress Fibers in Fibroblasts
2004
Members of the Raf family of serine/threonine protein kinases have been well studied in a variety of organisms ranging from Drosophila to humans. Three raf homologues (raf-1, B-raf, and A-raf) exist in mammals, while a single prototypic homologue exists in lower organisms. A wealth of genetic and biochemical data have indicated that Raf family members are signaling kinases that are integral components of the conserved Ras/Raf/MEK/ERK signaling cascade. Following activation by Ras-dependent mechanisms, Raf protein kinases act as mitogen-activated protein (MAP) kinase kinase kinases, which phosphorylate and activate the type 1/2 MAP kinase kinases, also known as MEK1/2. These dual-specificity…