scholarly journals Deimination, Intermediate Filaments and Associated Proteins

2020 ◽  
Vol 21 (22) ◽  
pp. 8746
Author(s):  
Julie Briot ◽  
Michel Simon ◽  
Marie-Claire Méchin
Keyword(s):  
Rheumatoid Arthritis ◽  
Multiple Sclerosis ◽  
Cell Differentiation ◽  
Intermediate Filaments ◽  
Cross Linking ◽  
Post Translational Modification ◽  
Innate And Adaptive Immunity ◽  
Calcium Dependent ◽  
Physiological Processes ◽  
Associated Proteins

Deimination (or citrullination) is a post-translational modification catalyzed by a calcium-dependent enzyme family of five peptidylarginine deiminases (PADs). Deimination is involved in physiological processes (cell differentiation, embryogenesis, innate and adaptive immunity, etc.) and in autoimmune diseases (rheumatoid arthritis, multiple sclerosis and lupus), cancers and neurodegenerative diseases. Intermediate filaments (IF) and associated proteins (IFAP) are major substrates of PADs. Here, we focus on the effects of deimination on the polymerization and solubility properties of IF proteins and on the proteolysis and cross-linking of IFAP, to finally expose some features of interest and some limitations of citrullinomes.

scholarly journals Citrullination – small change with a great consequence

2013 ◽  
Vol 9 ◽  
pp. 17-25 ◽  
Author(s):  
Mariusz Gogól
Keyword(s):  
Rheumatoid Arthritis ◽  
Gene Expression ◽  
Multiple Sclerosis ◽  
Positive Charge ◽  
Regulation Of Gene Expression ◽  
Slight Modification ◽  
Post Translational Modifications ◽  
Myelin Sheaths ◽  
Physiological Processes ◽  
Small Change

Citrullination is one of the possible post-translational modifications of proteins. It is based on a conversion of L-arginine residue (L-Arg) to L-citrulline residue (L-Cit). The reaction is catalyzed by peptidylarginine deiminases (PAD). The change of L-Arg imino moiety results in a loss of a positive charge. This slight modification can contribute to significant changes in physicochemical properties of proteins, which may also cause a change of their functions. Citrullination is the modification observed in physiological processes such as epidermal keratinization, regulation of gene expression and the reorganization of myelin sheaths. The changes in the efficacy of citrullination may contribute to the pathogenesis of many different diseases including: psoriasis, multiple sclerosis, rheumatoid arthritis and cancer.

scholarly journals Vitamin D, Inflammation and Osteoporosis in Rheumatoid Arthritis

2018 ◽  
Vol 12 (1) ◽  
pp. 300-312 ◽  
Author(s):  
Pier Paolo Sainaghi ◽  
Antonello Gibbin
Keyword(s):  
Rheumatoid Arthritis ◽  
Vitamin D ◽  
Parathyroid Hormone ◽  
Bone Loss ◽  
Adaptive Immunity ◽  
Bone Health ◽  
Fragility Fractures ◽  
Molecular Pathways ◽  
Innate And Adaptive Immunity ◽  
Physiological Processes

Patients with Rheumatoid Arthritis (RA) commonly develop osteoporosis and fragility fractures. This fact cannot be explained only with the use of glucocorticoids, known to be detrimental for bone health. RA is characterized by a chronic inflammation caused by the continuous activation of innate and adaptive immunity with proinflammatory cytokines overproduction. This process is detrimental for several organs and physiological processes, including the impairment of bone remodeling. We will briefly review the pathogenesis of inflammation-related bone loss in RA, describing well-known and new molecular pathways and focusing on vitamin D and Parathyroid Hormone role.

Filaments and membranes in the mitotic apparatus

1983 ◽  
Vol 41 ◽  
pp. 544-547
Author(s):  
Kent McDonald
Keyword(s):  
Intermediate Filaments ◽  
Mitotic Spindle ◽  
Mitotic Apparatus ◽  
Light Microscope Level ◽  
Microtubule Associated Proteins ◽  
Recent Developments ◽  
Associated Proteins ◽  
Force Generator ◽  
Spindle Function ◽  
Antibody Technology

At the light microscope level the recent developments and interest in antibody technology have permitted the localization of certain non-microtubule proteins within the mitotic spindle, e.g., calmodulin, actin, intermediate filaments, protein kinases and various microtubule associated proteins. Also, the use of fluorescent probes like chlorotetracycline suggest the presence of membranes in the spindle. Localization of non-microtubule structures in the spindle at the EM level has been less rewarding. Some mitosis researchers, e.g., Rarer, have maintained that actin is involved in mitosis movements though the bulk of evidence argues against this interpretation. Others suggest that a microtrabecular network such as found in chromatophore granule movement might be a possible force generator but there is little evidence for or against this view. At the level of regulation of spindle function, Harris and more recently Hepler have argued for the importance of studying spindle membranes. Hepler also believes that membranes might play a structural or mechanical role in moving chromosomes.

Mislocalization of Adherens Junction- Associated Proteins in a Patient with Darier Disease

2018 ◽  
Vol 2 (3) ◽  
pp. 184-201
Author(s):  
George D Glinos ◽  
Irena Pastar ◽  
Marjana Tomic-Canic ◽  
Rivka C Stone
Keyword(s):  
Adherens Junction ◽  
Cellular Adhesion ◽  
Calcium Flux ◽  
Keratinocyte Differentiation ◽  
Calcium Dependent ◽  
Endoplasmic Reticulum Calcium ◽  
Darier Disease ◽  
Associated Proteins ◽  
Attachment Proteins ◽  
E Cadherin

Darier disease (DD) is an autosomal dominant keratinizing genodermatosis that manifests clinically with red-brown pruritic papules in a seborrheic distribution often in association with palmoplantar pits and dystrophic nail changes. It is caused by mutation in ATP2A2 which encodes a sarco/endoplasmic reticulum calcium ATPase isoform 2 (SERCA2) pump that regulates calcium flux. Consequent alteration of intracellular calcium homeostasis is thought to impair trafficking of cellular adhesion proteins and to lead to aberrant keratinocyte differentiation, contributing to the characteristic histopathologic features of acantholysis and dyskeratosis in DD, though the precise mechanisms are incompletely understood. Previous studies have identified defective localization of desmosomal attachment proteins in skin biopsies and cultured keratinocytes from DD patients, but reports of effects on adherens junction proteins (including calcium-dependent E-cadherin) are conflicting. Here we describe a case of DD presenting with characteristic clinical and histologic features in which we performed immunofluorescence staining of four adherens junction-associated proteins (E-cadherin, α-catenin, β-catenin, and vinculin). In lesional (acantholytic) DD skin, we identified loss of distinctive bright membranous staining that was present at the periphery of keratinocytes throughout the epidermis in the healthy skin of a matched donor. Perilesional (non-acantholytic) portions of DD skin partially recapitulated the normal phenotype. Our findings support a role for SERCA2 dysfunction in impaired assembly of adherens junctions, which together with defective desmosomes contribute to acantholysis in DD.

Cell-based Tolerogenic Therapy, Experience from Animal Models of Multiple Sclerosis, Type 1 Diabetes and Rheumatoid Arthritis

2017 ◽  
Vol 23 (18) ◽  
Author(s):  
Ivana Stojanovic ◽  
Mirjana Dimitrijevic ◽  
Marta Vives-Pi ◽  
Maria Jose Mansilla ◽  
Irma Pujol-Autonell ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Multiple Sclerosis ◽  
Type 1 Diabetes ◽  
Animal Models

scholarly journals Solar Radiation and Vitamin D: Mitigating Environmental Factors in Autoimmune Disease

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Gerry K. Schwalfenberg
Keyword(s):  
Rheumatoid Arthritis ◽  
Multiple Sclerosis ◽  
Inflammatory Bowel Disease ◽  
Vitamin D ◽  
Type 1 Diabetes ◽  
Autoimmune Disease ◽  
Solar Radiation ◽  
Inflammatory Bowel

This paper looks at the environmental role of vitamin D and solar radiation as risk reduction factors in autoimmune disease. Five diseases are considered: multiple sclerosis, type 1 diabetes, rheumatoid arthritis, autoimmune disease of the thyroid, and inflammatory bowel disease. Clinical relevant studies and factors that may indicate evidence that autoimmune disease is a vitamin D-sensitive disease are presented. Studies that have resulted in prevention or amelioration of some autoimmune disease are discussed. An example of the utility of supplementing vitamin D in an unusual autoimmune disease, idiopathic thrombocytic purpura, is presented.

The Molecular basis of Lactose Intolerance

2005 ◽  
Vol 88 (3) ◽  
pp. 157-202 ◽  
Author(s):  
Anthony K. Campbell ◽  
Jonathan P. Waud ◽  
Stephanie B. Matthews
Keyword(s):  
Rheumatoid Arthritis ◽  
Multiple Sclerosis ◽  
Molecular Basis ◽  
Charles Darwin ◽  
Lactose Intolerance ◽  
Anaerobic Bacteria ◽  
Bacterial Toxins ◽  
Systemic Symptoms ◽  
Lactase Gene ◽  
Over 40 Years

A staggering 4000 million people cannot digest lactose, the sugar in milk, properly. All mammals, apart from white Northern Europeans and few tribes in Africa and Asia, lose most of their lactase, the enzyme that cleaves lactose into galactose and glucose, after weaning. Lactose intolerance causes gut and a range of systemic symptoms, though the threshold to lactose varies considerably between ethnic groups and individuals within a group. The molecular basis of inherited hypolactasia has yet to be identified, though two polymorphisms in the introns of a helicase upstream from the lactase gene correlate closely with hypolactasia, and thus lactose intolerance. The symptoms of lactose intolerance are caused by gases and toxins produced by anaerobic bacteria in the large intestine. Bacterial toxins may play a key role in several other diseases, such as diabetes, rheumatoid arthritis, multiple sclerosis and some cancers. The problem of lactose intolerance has been exacerbated because of the addition of products containing lactose to various foods and drinks without being on the label. Lactose intolerance fits exactly the illness that Charles Darwin suffered from for over 40 years, and yet was never diagnosed. Darwin missed something else – the key to our own evolution – the Rubicon some 300 million years ago that produced lactose and lactase in sufficient amounts to be susceptible to natural selection.

Tetrins: polypeptides that form bundled filaments in Tetrahymena

1990 ◽  
Vol 96 (2) ◽  
pp. 293-302
Author(s):  
J.E. Honts ◽  
N.E. Williams
Keyword(s):  
Intermediate Filaments ◽  
Tetrahymena Pyriformis ◽  
Ciliated Protozoan ◽  
Microtubule Associated Proteins ◽  
Fine Filament ◽  
Helical Content ◽  
In Vitro Assembly ◽  
Associated Proteins ◽  
Filament Bundles

The cortex of the ciliated protozoan Tetrahymena contains a number of fibrous elements, including a network of filaments that pervades the feeding organelle of this organism. The cluster of polypeptides (79–89K; K = 10(3) Mr) in Tetrahymena pyriformis GL-C that constitute these filaments has been purified by in vitro assembly after solubilization in 1.0 M KI. Four distinct sets of these polypeptides, designated ‘tetrins’, have been shown to be distinguishable from each other by immunochemical and biochemical criteria. The smallest filaments reassembled in vitro were 3–4 nm in diameter and these fine filaments were seen to be bundled together into thicker strands of varying diameters, similar to those within the cell. The thicker filament bundles were clearly distinguishable from intermediate filaments, but fine filaments in these bundles were superficially similar to the 2–5 nm filaments described as microtubule-associated proteins in other organisms. The ultrastructure of the tetrin filaments localized within the feeding organelle reveals a substantial presence of these filaments apart from microtubules. In addition, circular dichroism measurements indicate a relatively low alpha-helical content for these filaments and suggest that the tetrins may be substantially different from other fine filament proteins such as the tektins and giardins.

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