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The Journal of Biological Chemistry Dec 1982Axenic cultures of Paramecium tetraurelia take up 32Pi and phosphorylate a number of polypeptides as determined by autoradiography following sodium dodecyl... (Comparative Study)
Comparative Study
Axenic cultures of Paramecium tetraurelia take up 32Pi and phosphorylate a number of polypeptides as determined by autoradiography following sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The most heavily labeled polypeptide has an apparent Mr of approximately 65,000. Wild type cells stimulated to secrete with picric acid, the standard secretagogue for these cells, show a marked reduction in labeling of the 65,000 Mr polypeptide. There is no change in the Coomassic blue staining protein pattern after addition of picric acid. Addition of picric acid to cells solubilized in sample buffer containing 10% sodium dodecyl sulfate, significantly lowers the pH but does not induce dephosphorylation of the 65,000 Mr polypeptide. Dephosphorylation of the 65,000 Mr polypeptide is further correlated with secretion in two types of experiments. 1) Preincubation of cells in Mg2+ (no added Ca2+) inhibits both secretion and dephosphorylation in response to picric acid. 2) A temperature-sensitive mutant, nd 9, when grown at 18 degrees C (permissive temperature) has the normal intramembrane particle array (rosette) at the secretory site and secretes and dephosphorylates the 65,000 Mr polypeptide in response to picric acid, but when grown at 27 degrees C (nonpermissive temperature) does not have assembled rosettes at the secretory site, and does not secrete nor dephosphorylate the 65,000 Mr polypeptide in response to picric acid. This represents the first correlation between a phosphoprotein and a physiological activity (secretion) in Paramecium. Our results show the presence of an in vivo stimulus-sensitive phosphoprotein of Mr 65,000 which appears related to Ca2+-mediated exocytosis. Inhibition of dephosphorylation occurs when secretion is blocked, either by Mg2+ or by a mutation affecting an intramembrane particle array, the rosette.
Topics: Animals; Magnesium; Molecular Weight; Mutation; Paramecium; Phosphoproteins; Phosphorylation; Proteins; Species Specificity; Temperature
PubMed: 7142183
DOI: No ID Found -
Microbiology Spectrum Jan 2019Members of the phylum have many unique features, including gliding motility and the type IX protein secretion system (T9SS). gliding and T9SSs are common in, but...
Members of the phylum have many unique features, including gliding motility and the type IX protein secretion system (T9SS). gliding and T9SSs are common in, but apparently confined to, this phylum. Most, but not all, members of the phylum secrete proteins using the T9SS, and most also exhibit gliding motility. T9SSs secrete cell surface components of the gliding motility machinery and also secrete many extracellular or cell surface enzymes, adhesins, and virulence factors. The components of the T9SS are novel and are unrelated to those of other bacterial secretion systems. Proteins secreted by the T9SS rely on the Sec system to cross the cytoplasmic membrane, and they use the T9SS for delivery across the outer membrane. Secreted proteins typically have conserved C-terminal domains that target them to the T9SS. Some of the T9SS components were initially identified as proteins required for gliding motility. Gliding does not involve flagella or pili and instead relies on the rapid movement of motility adhesins, such as SprB, along the cell surface by the gliding motor. Contact of the adhesins with the substratum provides the traction that results in cell movement. SprB and other motility adhesins are delivered to the cell surface by the T9SS. Gliding and the T9SS appear to be intertwined, and components of the T9SS that span the cytoplasmic membrane may energize both gliding and protein secretion. The functions of the individual proteins in each process are the subject of ongoing investigations.
Topics: Adhesins, Bacterial; Bacterial Secretion Systems; Bacteroidetes; Locomotion; Protein Transport
PubMed: 30767845
DOI: 10.1128/microbiolspec.PSIB-0002-2018 -
Basic & Clinical Pharmacology &... Mar 2015Viscoelastic mucus lines all mucosal surfaces of the body and forms a potential barrier to mucosal drug delivery. Mucus is mainly composed of water and mucins; high... (Review)
Review
Viscoelastic mucus lines all mucosal surfaces of the body and forms a potential barrier to mucosal drug delivery. Mucus is mainly composed of water and mucins; high molecular weight glycoproteins forming an entangled network. Consequently, mucus forms a steric barrier, and due to its negative charge and hydrophobic domains, the overall hydrophilic mucus also presents an interactive barrier limiting the free diffusion of components within and through the mucus. Furthermore, mucus is a dynamic barrier due to its continuous secretion and shedding from the mucosal surfaces. Mucus is thus a highly complex gel barrier to drug delivery. Current knowledge of mucus characteristics and barrier properties, as achieved by state-of-the-art methodologies, is the topic of this MiniReview emphasizing the gastrointestinal mucus and an overall focus on oral drug delivery. Cell culture-based in vitro models are well-established as essential tools in drug research and development, but traditionally, mucus-containing models have only rarely been applied. However, a number of mucus-containing in vitro models have recently been described in the literature, and their properties and applications will be reviewed and discussed. Finally, studies of peptide and protein drug diffusion in and through mucus and studies of mucus-penetrating nanoparticles are included to illustrate the mucus as a potentially important barrier to obtain sufficient bioavailability of orally administered drugs, and thus an important parameter to address in the development of future oral drug delivery systems.
Topics: Administration, Oral; Animals; Biological Availability; Drug Delivery Systems; Drug Design; Humans; Models, Biological; Mucins; Mucus; Nanoparticles; Peptides; Proteins
PubMed: 25349046
DOI: 10.1111/bcpt.12342 -
Clinical and Experimental Immunology Nov 2018Dipeptidyl peptidase 4 (DPP4, CD26) is a serine protease that is expressed constitutively by many haematopoietic and non-haematopoietic tissues. It exists as a... (Review)
Review
Dipeptidyl peptidase 4 (DPP4, CD26) is a serine protease that is expressed constitutively by many haematopoietic and non-haematopoietic tissues. It exists as a membrane-associated protein, as well as in an active, soluble form (herein called sDPP4), present at high concentrations in bodily fluids. Despite the proposed use of sDPP4 as a biomarker for multiple diseases, its cellular sources are not well defined. Here, we report that individuals with congenital lymphocyte immunodeficiency had markedly lower serum concentrations of sDPP4, which were restored upon successful treatment and restoration of lymphocyte haematopoiesis. Using irradiated lymphopenic mice and wild-type to Dpp4 reciprocal bone marrow chimeric animals, we found that haematopoietic cells were a major source of circulating sDPP4. Furthermore, activation of human and mouse T lymphocytes resulted in increased sDPP4, providing a mechanistic link between immune system activation and sDPP4 concentration. Finally, we observed that acute viral infection induced a transient increase in sDPP4, which correlated with the expansion of antigen-specific CD8 T cell responses. Our study demonstrates that sDPP4 concentrations are determined by the frequency and activation state of lymphocyte populations. Insights from these studies will support the use of sDPP4 concentration as a biomarker for inflammatory and infectious diseases.
Topics: Animals; Biomarkers; Bodily Secretions; Dipeptidyl Peptidase 4; Disease Models, Animal; Hematopoiesis; Humans; Influenza A virus; Membrane Proteins; Mice; Mice, Inbred C57BL; Mice, Knockout; Orthomyxoviridae Infections; Severe Combined Immunodeficiency; Solubility; T-Lymphocytes; Transplantation Chimera
PubMed: 30251416
DOI: 10.1111/cei.13163 -
Biological & Pharmaceutical Bulletin 2011Gastric proton pump (H⁺, K⁺-ATPase) secretes H⁺ of acid (HCl) via the luminal membrane of parietal cells. For the HCl secretion, Cl⁻- and K⁺-transporting... (Review)
Review
Gastric proton pump (H⁺, K⁺-ATPase) secretes H⁺ of acid (HCl) via the luminal membrane of parietal cells. For the HCl secretion, Cl⁻- and K⁺-transporting proteins are required. Recent our studies have demonstrated that K⁺-Cl⁻ cotransporters (KCC3a and KCC4) are expressed in gastric parietal cells. KCC3a is associated with Na⁺, K⁺-ATPase in the basolateral membrane, and KCC4 is associated with H⁺, K⁺-ATPase in the apical canalicular membrane. This paper summarizes the functional association between KCCs and P-type ATPases and the contribution of these complexes to acid secretion in gastric parietal cells.
Topics: Animals; Cell Polarity; Gastric Acid; Humans; Membrane Microdomains; Parietal Cells, Gastric; Protein Isoforms; Proton Pumps; Secretory Pathway; Sodium-Potassium-Exchanging ATPase; Symporters
PubMed: 21628876
DOI: 10.1248/bpb.34.810 -
The Journal of Allergy and Clinical... Oct 2014I review how diverse inherited and acquired abnormalities in epidermal structural and enzymatic proteins converge to produce defective permeability barrier function and... (Review)
Review
I review how diverse inherited and acquired abnormalities in epidermal structural and enzymatic proteins converge to produce defective permeability barrier function and antimicrobial defense in patients with atopic dermatitis (AD). Although best known are mutations in filaggrin (FLG), mutations in other member of the fused S-100 family of proteins (ie, hornerin [hrn] and filaggrin 2 [flg-2]); the cornified envelope precursor (ie, SPRR3); mattrin, which is encoded by TMEM79 and regulates the assembly of lamellar bodies; SPINK5, which encodes the serine protease inhibitor lymphoepithelial Kazal-type trypsin inhibitor type 1; and the fatty acid transporter fatty acid transport protein 4 have all been linked to AD. Yet these abnormalities often only predispose to AD; additional acquired stressors that further compromise barrier function, such as psychological stress, low ambient humidity, or high-pH surfactants, often are required to trigger disease. T(H)2 cytokines can also compromise barrier function by downregulating expression of multiple epidermal structural proteins, lipid synthetic enzymes, and antimicrobial peptides. All of these inherited and acquired abnormalities converge on the lamellar body secretory system, producing abnormalities in lipid composition, secretion, and/or extracellular lamellar membrane organization, as well as antimicrobial defense. Finally, I briefly review therapeutic options that address this new pathogenic paradigm.
Topics: Animals; Bodily Secretions; Dermatitis, Atopic; Fatty Acid Transport Proteins; Filaggrin Proteins; Gene-Environment Interaction; Humans; Immunity, Innate; Inclusion Bodies; Intermediate Filament Proteins; Lipid Metabolism; Membrane Proteins; Proteinase Inhibitory Proteins, Secretory; Proteolysis; Serine Peptidase Inhibitor Kazal-Type 5; Skin
PubMed: 25131691
DOI: 10.1016/j.jaci.2014.05.048 -
World Journal of Gastroenterology Nov 2013This review considers the physiological and molecular biochemical mechanisms of bile formation. The composition of bile and structure of a bile canaliculus, biosynthesis... (Review)
Review
This review considers the physiological and molecular biochemical mechanisms of bile formation. The composition of bile and structure of a bile canaliculus, biosynthesis and conjugation of bile acids, bile phospholipids, formation of bile micellar structures, and enterohepatic circulation of bile acids are described. In general, the review focuses on the molecular physiology of the transporting systems of the hepatocyte sinusoidal and apical membranes. Knowledge of physiological and biochemical basis of bile formation has implications for understanding the mechanisms of development of pathological processes, associated with diseases of the liver and biliary tract.
Topics: Animals; Bile; Bile Pigments; Biliary Tract; Biological Transport; Carrier Proteins; Cellulose, Oxidized; Enterohepatic Circulation; Humans; Liver; Membrane Glycoproteins; Micelles; Phospholipids
PubMed: 24259965
DOI: 10.3748/wjg.v19.i42.7341 -
Journal of Separation Science Oct 2021Human whole saliva is a bodily fluid that can be obtained easily by noninvasive techniques. Specimens can be collected by the patient also at home in order to monitor... (Review)
Review
Human whole saliva is a bodily fluid that can be obtained easily by noninvasive techniques. Specimens can be collected by the patient also at home in order to monitor health status and variations of several analytes of clinical interest. The contributions to whole saliva include secretions from salivary glands and, among others, from the gingival crevicular fluid that derives from the epithelial mucosa. Therefore, saliva is currently a relevant diagnostic fluid for many substances, including steroids, nonpeptide hormones, therapeutic drugs, and drugs of abuse. This review at first briefly describes the different contributions to whole saliva. A section illustrates the procedures for the collection, handling, and storage of salivary specimens. Another section describes the present use of whole saliva for diagnostic purposes and its specific utilization for the diagnosis of several local and systemic diseases. The final sections illustrate the future opportunities offered by various not conventional techniques with a focus on the most recent -omic investigations. It describes the various issues that have to be taken into account to avoid false positives and negatives, such as the strength of the experimental plan, the adequacy of the number of samples under study, and the proper choice of controls.
Topics: Biomarkers; Humans; Proteome; Proteomics; Saliva
PubMed: 34350708
DOI: 10.1002/jssc.202100384 -
Digestive Diseases (Basel, Switzerland) 2021Mucus protects the epithelium against invaders and toxic materials. Sticky and thick mucus is characteristic of CF.
BACKGROUND
Mucus protects the epithelium against invaders and toxic materials. Sticky and thick mucus is characteristic of CF.
OBJECTIVE
The aim of this systematic review is to characterize the specific mucins secreted in the lung and intestinal tract of CF patients.
METHODS
A systematic literature search was conducted up to December 31, 2019. The following terms were used: "cystic fibrosis" AND "mucin." Case-control studies comparing mucin expression in CF patients to healthy controls were included.
RESULTS
We found 741 eligible studies, 694 studies were rejected because they were performed in animals and not in full text, and 32 studies were excluded being editorials, duplications, review articles, meta-analysis, or not in English. Fifteen studies were eligible for our study, including 150 CF patients compared to 82 healthy controls, all fulfilled the inclusion criteria. The main mucin types expressed in the sinus submucosal glands, sputum, tracheobronchial surface epithelium, and lung submucosal glands were MUC5AC and MUC5B. Increase in the number of sinusoidal submucosal glands and expression of MUC5B was found in CF patients, but no such difference from healthy controls was found for the number of goblet cells in the surface epithelium nor in the expression of -MUC5AC. The opposite was found in the tracheobronchial surface epithelium and in the lungs.
CONCLUSIONS
Increased expression of MUC5AC in the surface epithelium and of MUC5B in the subepithelial glands may be the result of higher secretion rate of mucin into the lumen of the respiratory tract, causing mucus plaque, infection, and inflammation.
Topics: Animals; Bodily Secretions; Case-Control Studies; Cystic Fibrosis; Gastrointestinal Tract; Humans; Lung; Mucin 5AC; Mucin-5B; Mucins
PubMed: 33049746
DOI: 10.1159/000512268 -
Current Allergy and Asthma Reports Oct 2018IgE is a key player in multiple inflammatory airway diseases. Ample literature demonstrates its presence in mucosa of patients with allergic rhinitis (AR), local... (Review)
Review
PURPOSE OF REVIEW
IgE is a key player in multiple inflammatory airway diseases. Ample literature demonstrates its presence in mucosa of patients with allergic rhinitis (AR), local allergic rhinitis (LAR), asthma, or chronic rhinosinusitis with nasal polyposis (CRSwNP).
RECENT FINDINGS
Current evidence shows that high-affinity IgE in blood stream of allergic individuals derives mainly from the mucosae. Also, mucosal synthesis of IgE can occur in the absence of systemic atopy, and may be relevant in atopic and non-atopic phenotypes of rhinitis as demonstrated in LAR. Specific IgE (sIgE) detection varies depending on technique used for sample collection and its measurement. sIgE detection is highly specific for diagnosis of LAR. Moreover, measurement of sIgE in secretions could be useful in monitoring response to allergen-specific immunotherapy in both AR and LAR phenotypes. This review will focus on recent developments in the role of IgE in respiratory diseases, and the clinical implications of its measurement in secretions.
Topics: Bodily Secretions; Diagnostic Techniques and Procedures; Humans; Immunoglobulin E; Respiratory Mucosa; Rhinitis, Allergic
PubMed: 30317418
DOI: 10.1007/s11882-018-0821-7