Apical enzyme

The transition from active growth to dormancy is critical for the survival of perennial plants. We identified a DEMETER-like (CsDML) cDNA from a winter-enriched cDNA subtractive library in chestnut (Castanea sativa Mill.), an economically and ecologically important species. Next, we characterized this DNA demethylase and its putative orthologue in the more experimentally tractable hybrid poplar (Populus tremula x alba), under the signals that trigger bud dormancy in trees. We performed phylogenetic and protein sequence analysis, gene expression profiling and 5mC immunodetection studies to evaluate the role of CsDML and its homologue in poplar, PtaDML6...

Development of neural progenitors depends upon the coordination of appropriate intrinsic responses to extrinsic signalling pathways. Here we show the deubiquitylating enzyme, Usp9x regulates components of both intrinsic and extrinsic fate determinants. Nestin-cre mediated ablation of Usp9x from embryonic neural progenitors in vivo resulted in a transient disruption of cell adhesion and apical-basal polarity and, an increased number and ectopic localisation of intermediate neural progenitors. In contrast to other adhesion and polarity proteins, levels of β-catenin protein, especially S33/S37/T41 phospho-β-catenin, were markedly increased in Usp9x (-/Y) embryonic cortices...

Many landraces of cowpea [Vigna unguiculata (L.) Walp.] are adapted to particular geographical and climatic conditions. Here we describe two landraces grown respectively in arid and temperate areas of Algeria and assess their physiological and molecular responses to drought stress. As expected, when deprived of water cowpea plants lose water over time with a gradual reduction in transpiration rate. The landraces differed in their relative water content (RWC) and whole plant transpiration rate. The landrace from Menia, an arid area, retained more water in adult leaves...

The potato (Solanum tuberosum L.) tuber is a swollen underground stem that can sprout in an apical dominance (AD) pattern. Bromoethane (BE) induces loss of AD and the accumulation of vegetative vacuolar processing enzyme (StVPE) in the tuber apical meristem (TAM). VPE activity, induced by BE, is followed by programmed cell death in the TAM. In this study, we found that the mature StVPE1 protein (mVPE) exhibits specific activity for caspase-1, but not caspase-3 substrates. Optimal activity of mVPE was achieved at acidic pH, consistent with localization of StVPE1 to the vacuole, at the edge of the TAM...

Ecto-5' -nucleotidase (CD73) is expressed abundantly on the apical surface of intestinal epithelial cells (IEC) and functions as the terminal enzyme in the generation of extracellular adenosine. Previous work has demonstrated that adenosine signaling in IECs results in a number of tissue-protective effects during inflammation; however, a rationale for its apical expression has been lacking. We hypothesized that the highly polarized expression of CD73 is indicative of an important role for extracellular adenosine as a mediator of host-microbe interactions...

Phosphatidylinositol 3-kinase (PI3K) is a key enzyme that phosphorylates phosphatidylinositol at 3'-hydroxyl position of the inositol head group initiating the generation of several phosphorylated phosphatidylinositols, collectively referred to as phosphoinositides. The function of PI3K in plant senescence and ethylene signal transduction process was studied by expression of Solanum lycopersicum PI3K in transgenic Nicotiana tabacum, and delineating its effect on flower senescence. Detached flowers of transgenic tobacco plants with overexpressed Sl-PI3K (OX) displayed accelerated senescence and reduced longevity, when compared to the flowers of wild type plants...

CX3CL1 has been implicated in allergen-induced airway CD4(+) T-lymphocyte recruitment in asthma. As epidemiological evidence supports a viral infection-allergen synergy in asthma exacerbations, we postulated that rhinovirus (RV) infection in the presence of allergen augments epithelial CX3CL1 release. Fully differentiated primary bronchial epithelial cultures were pretreated apically with house dust mite (HDM) extract and infected with rhinovirus-16 (RV16). CX3CL1 was measured by enzyme-linked immunosorbent assay and western blotting, and shedding mechanisms assessed using inhibitors, protease-activated receptor-2 (PAR-2) agonist, and recombinant CX3CL1-expressing HEK293T cells...

Leptin, a highly conserved adipocyte-derived hormone, plays important roles in a variety of physiological processes, including the control of fat storage and metabolic status which are linked to food intake, energy homeostasis, and reproduction in all vertebrates. In the present study, we hypothesize that leptin is also present in various organs of the fresh water prawns, Macrobrachium rosenbergii. The existence and distribution of a leptin-like peptide in prawn tissues were verified by using Western blotting (WB) and immunohistochemical detection (ID) using primary antibody against human leptin...

The primary hepatocytes culture is still one of the main challenges in toxicology studies in the drug discovery process, development of in vitro models to study liver function, and cell-based therapies. Isolated hepatocytes display a rapid decline in viability and liver-specific functions including albumin production, conversion of ammonia to urea, and activity of the drug metabolizing enzymes. A number of methods have been developed in order to maintain hepatocytes in their highly differentiated state in vitro...

In plants and protists, dihydrofolate reductase (DHFR) and thymidylate synthase (TS) are part of a bifunctional enzyme (DRTS) that allows efficient recycling of the dihydrofolate resulting from TS activity. Arabidopsis thaliana possesses three DRTS genes, called AtDRTS1, AtDRTS2 and AtDRTS3, that are located downstream of three members of the sec14-like SFH gene family. In this study, a characterization of the AtDRTS genes identified alternatively spliced transcripts coding for AtDRTS isoforms which may account for monofunctional DHFR enzymes supporting pathways unrelated to DNA synthesis...

An emerging vision for toxicity testing in the 21st century foresees in vitro assays assuming the leading role in testing for chemical hazards, including testing for carcinogenicity. Toxicity will be determined by monitoring key steps in functionally validated molecular pathways, using tests designed to reveal chemically-induced perturbations that lead to adverse phenotypic endpoints in cultured human cells. Risk assessments would subsequently be derived from the causal in vitro endpoints and concentration vs...

INTRODUCTION: MicroRNA-335-5p has been reported to regulate osteogenic and chondrogenic differentiations of mesenchymal stem cells. The aim of this study was to explore the function and regulation mechanism of miR-335-5p in apical periodontitis (AP). METHODS: Total RNAs were extracted from human periodontal ligament fibroblasts (HPDLFs), 10 AP tissues, and 6 healthy periodontal ligament tissues using lysis buffer. Gene expression was detected using real-time polymerase chain reaction...

Plants are known for their capacity to regenerate the whole body through de novo formation of apical meristems from a mass of proliferating cells named callus. Exogenous cytokinin and auxin determine cell fate for the establishment of the stem cell niche, which is the vital step of shoot regeneration, but the underlying mechanisms remain unclear. Here, we show that type-B ARABIDOPSIS RESPONSE REGULATORs (ARRs), critical components of cytokinin signaling, activate the transcription of WUSCHEL (WUS), which encodes a key regulator for maintaining stem cells...

Ceramides (Cers) and complex sphingolipids with defined acyl chain lengths play important roles in numerous cell processes. Six Cer synthase (CerS) isoenzymes (CerS1-6) are the key enzymes responsible for the production of the diversity of molecular species. In this study, we investigated the changes in sphingolipid metabolism during the differentiation of Madin-Darby canine kidney (MDCK) cells. By MALDI TOF TOF MS, we analyzed the molecular species of Cer, glucosylceramide (GlcCer), lactosylceramide (LacCer), and SM in nondifferentiated and differentiated cells (cultured under hypertonicity)...

PURPOSE: We have shown previously that non-enzymatic nitration (NEN) of the extracellular matrix (ECM), which serves as a model of Bruch's membrane (BM) aging, has a profound effect on the behavior of the overlying retinal pigment epithelial (RPE) cells, including altered phagocytic ability, reduced cell adhesion, and inhibition of proliferation. We know that transplanted RPE monolayers will encounter a hostile sub-RPE environment, including age-related alterations in BM that may compromise cell function and survival...

The mechanisms that power the physiological events occurring in cilia, flagella, and microvilli are of fundamental importance for the functions of these important and ubicuous organelles. The olfactory epithelium is mostly populated by ciliated olfactory sensory neurons (OSNs) and surrounding sustentacular cells (SCs) with apical microvilli. The only OSN dendrite extends to the surface forming a knob projecting several chemosensory cilia of ∼50 × 0.2 μm, devoid of inner membranes embedded in a mucus layer...

SUMMARY: Takotsubo cardiomyopathy (TC) is an atypical, severe but reversible form of acute heart insufficiency. It typically presents with left ventricular failure, transient apical and mid-segments hypokinesis, absence of significant coronary stenosis and new electrographic abnormalities and/or elevation in serum cardiac enzymes. Although TC ('broken heart syndrome') has classically been associated with emotional trauma, evidence suggests that other precipitants might exist, including iatrogenic and thyroid-mediated forms...

Objectives: The early phase of orthodontic tooth movement involves acute inflammatory response that may induce bone resorption. The aim of this study was to localize and quantify cells in the periodontium expressing proinflammatory mediators during orthodontically induced periapical root resorption of the rat mandibular molars. Materials and methods: The levels of proinflammatory cytokines interleukin-1 (IL-1) α and β, tumor necrosis factor-α (TNF-α), inflammatory enzymes cyclooxygenase (COX) 1 and 2, and their product prostaglandin E2 (PGE2) in the root resorption site were compared to those in the corresponding area of the untreated periodontal ligament (PDL) of physiologically drifting teeth...

Aspartic proteases (Aps, EC3.4.23) are one of the 4 major mechanistic classes of proteolytic enzymes with the conserved motifs Asp-Thr/Ser-Gly (DT/SG) at the active site and are activated at acidic pH. In Arabidopsis, 69 genes were identified as coding putative aspartic proteinases. However, little is known about most of these enzymes. Recently, we characterized 2 novel Arabidopsis Aps genes, A36 and A39, which encode 2 putative GPI-anchored pollen-high-expressed Aps. a36 a39 mutants display significant abortion...

INTRODUCTION: This study was conducted to observe the immunohistochemical localization of high-mobility group box 1 (HMGB1) and its receptor, Toll-like receptor 4 (TRL4), in the development of periapical lesions induced in rats. The possible role of these molecules in the pathogenesis of periapical lesions was also explored. METHODS: Periapical lesions developed within 35 days after mandibular first molar pulp exposure in Wistar rats. The animals were randomly killed at 0, 7, 14, 21, 28, and 35 days after pulp exposure...