A novel protein derived from the MUC1 gene by alternative splicing and frameshifting

Genes that have been designated the name "MUC" code for proteins comprising mucin domains. These proteins may be involved in barrier and protective functions. The first such gene to be characterized and sequenced is the MUC1 gene. Here we report a novel small protein derived from the MUC1 gene by alternative splicing that does not contain the hallmark of mucin proteins, the mucin domain. This protein termed MUC1/ZD retains the same N-terminal MUC1 sequences as all of the other known MUC1 protein isoforms. The common N-terminal sequences comprise the signal peptide and a subsequent stretch of 30 amino acids. In contrast, the MUC1/ZD C-terminal 43 amino acids are novel and result from a reading frameshift engendered by a splicing event that forms MUC1/ZD. The expression of MUC1/ZD at the protein level in human tissues is demonstrated by Western blotting, immunohistochemistry, immunoprecipitation, and an ELISA. Utilization was made of affinity-purified MUC1/ZD-specific polyclonal antibodies as well as two different monoclonal antibodies that are monospecific for the MUC1/ZD protein. The MUC1/ZD protein is expressed in tissues as an oligomeric complex composed of monomers linked by disulfide bonds contributed by MUC1/ZD cysteine residues. MUC1/ZD protein expression did not parallel that of the tandem-repeat array-containing MUC1 protein. Results presented here demonstrate for the first time the expression of a novel MUC1 protein isoform MUC1/ZD, which is generated by an alternative splicing event that both deletes the tandem-repeat array and leads to a C-terminal reading frameshift.     

Woodstoich III: Integrating tools of nutritional geometry and ecological stoichiometry to advance nutrient budgeting and the prediction of consumer‐driven nutrient recycling

Within the last two decades, ecological stoichiometry (ES) and nutritional geometry (NG, also known as geometric framework for nutrition) have delivered novel insights into core questions of nutritional ecology. These two nutritionally explicit frameworks differ in the ‘nutrient currency’ used and the focus of their past research; behavioural feeding strategies in NG, mainly investigating terrestrial organisms, and trophic ecology in ES, mainly in aquatic settings. However, both NG and ES have developed in explaining patterns across various scales of biological organization. Integrating specific tools of these frameworks could advance the field of nutritional ecology by unifying theoretical and empirical approaches from the organismal to ecosystem level processes. Toward this integration, we identified 1) nutrient/element budgets as a shared concept of both frameworks that encompass nutrient intake, retention, and release, 2) response surface plots of NG as powerful tools to illustrate processes at the organismal level and 3) the concept of consumer‐driven nutrient recycling (CNR) of ES as a useful tool bridging organism and ecosystem scales. We applied response surface plots to element budget data from an ES study to show how this approach can deliver new insights at the organismal level, e.g. by showing the interplay between egestion and excretion depending simultaneously on the consumed amount of carbon and phosphorus based on variation across individuals. By integrating concepts of ES and NG to model microbial uptake and mineralization of nitrogenous wastes reported in a NG study, we also demonstrate that considering biochemically explicit mineralization rates of organic wastes can improve predictions of CNR by reducing over‐ or underestimation of mineralization depending on the quality of the consumer's diet. Our presented tools and approaches can help to bridge the organismal and ecosystem level, advancing the predictive power of studies in nutritional ecology at multiple ecological scales.     

Artemisinin-derived dimer phosphate esters as potent anti-cytomegalovirus (anti-CMV) and anti-cancer agents: A structure–activity study

We recently reported the anti-cancer and anti-cytomegalovirus (CMV) activity of artemisinin-derived trioxane diphenylphosphate dimer 838. To probe the relationship between chemical structure and anti-CMV and anti-cancer activities, we now report synthesis and evaluation of a series of eight new dimer phosphate ester analogs of 838. This series of novel molecules was screened against human foreskin fibroblasts (HFFs) infected with CMV and against the human Jurkat T cell acute lymphoblastic leukemia cell line. This SAR study confirms the very high anti-CMV and anti-cancer potencies of dimer diphenyl phosphate ester 838 without its being toxic to normal cells.     

Neurons controlling Aplysia feeding inhibit themselves by continuous NO production

Background

Neural activity can be affected by nitric oxide (NO) produced by spiking neurons. Can neural activity also be affected by NO produced in neurons in the absence of spiking?

Methodology/Principal Findings

Applying an NO scavenger to quiescent Aplysia buccal ganglia initiated fictive feeding, indicating that NO production at rest inhibits feeding. The inhibition is in part via effects on neurons B31/B32, neurons initiating food consumption. Applying NO scavengers or nitric oxide synthase (NOS) blockers to B31/B32 neurons cultured in isolation caused inactive neurons to depolarize and fire, indicating that B31/B32 produce NO tonically without action potentials, and tonic NO production contributes to the B31/B32 resting potentials. Guanylyl cyclase blockers also caused depolarization and firing, indicating that the cGMP second messenger cascade, presumably activated by the tonic presence of NO, contributes to the B31/B32 resting potential. Blocking NO while voltage-clamping revealed an inward leak current, indicating that NO prevents this current from depolarizing the neuron. Blocking nitrergic transmission had no effect on a number of other cultured, isolated neurons. However, treatment with NO blockers did excite cerebral ganglion neuron C-PR, a command-like neuron initiating food-finding behavior, both in situ, and when the neuron was cultured in isolation, indicating that this neuron also inhibits itself by producing NO at rest.

Conclusion/Significance

Self-inhibitory, tonic NO production is a novel mechanism for the modulation of neural activity. Localization of this mechanism to critical neurons in different ganglia controlling different aspects of a behavior provides a mechanism by which a humeral signal affecting background NO production, such as the NO precursor L-arginine, could control multiple aspects of the behavior.     

Intraspecific variation of Chiliadenus iphionoides essential oil in Israel

Chiliadenus iphionoides (Asteraceae), a shrub endemic to the Mediterranean region and widespread throughout Israel, is used in the traditional eastern Mediterranean medicine. Although recent research confirmed its pharmacological potential, C. iphionoides essential oil has not been adequately characterized chemically. Essential-oil samples were collected from representative wild populations throughout Israel and characterized by GC/MS analysis. Considerable interpopulation variation was found for the composition of the essential oils. Multivariate analysis showed a significant correlation between the chemical composition and the geographic location, with three main chemotypes identified.     

Leaf mechanics and herbivory defence: How tough tissue along the leaf body deters growing insect herbivores

Research on herbivory defence often focuses on leaf chemistry but less on how plant mechanical properties like leaf veins deter herbivores. Herbivores often eat tough, complex plant tissue, yet how mechanical properties affect feeding performance as the consumer grows is unclear. We measured the toughness and strength of five types of leaf tissue – the midrib, the secondary and marginal veins and the lamina inside (inner) and outside (outer) the marginal vein – in mature Eucalyptus viminalis and Eucalyptus ovata leaves with punch tests. Leaf veins were, on average, 6.2 times tougher than lamina. Marginal veins were uniformly strong and tough along the leaf body, while midribs were less strong and secondary veins less tough toward leaf tips. We correlated the force required to puncture leaf tissue with the feeding performance of a chewing insect herbivore (the spiny leaf insect, Extatosoma tiaratum (Phasmida)) across four instar stages to explore the role of tough leaf veins as potential feeding barriers. Larvae more often ate less tough leaf tips and tougher tissue as they grew. However, younger larvae were capable of penetrating the tough marginal vein when starved. We suggest tough leaf veins and consumer position along the leaf body influence insect herbivore feeding performance over their lifetime.     

Genetic Relationship in Cicer Sp. Expose Evidence for Geneflow between the Cultigen and Its Wild Progenitor

There is a debate concerning mono- or poly-phyletic origins of the Near Eastern crops. In parallel, some authors claim that domestication was not possible within the natural range of the wild progenitors due to wild alleles flow into the nascent crops. Here we address both, the mono- or poly-phyletic origins and the domestications within or without the natural range of the progenitor, debates in order to understand the relationship between domesticated chickpea (Cicer arietinum L.) and its wild progenitor (C. reticulatum Ladizinsky) with special emphasis on its domestication centre in southeastern Turkey. A set of 103 chickpea cultivars and landraces from the major growing regions alongside wild accessions (C. reticulatum, C. echinospermum P.H Davis and C. bijugum K.H. Rech) sampled across the natural distribution range in eastern Turkey were genotyped with 194 SNPs markers. The genetic affinities between and within the studied taxa were assessed. The analysis suggests a mono-phyletic origin of the cultigen, with several wild accession as likely members of the wild stock of the cultigen. Clear separation between the wild and domesticated germplasm was apparent, with negligible level of admixture. A single C. reticulatum accession shows morphological and allelic signatures of admixture, a likely result of introgression. No evidence of geneflow from the wild into domesticated germplasm was found. The traditional farming systems of southeaster Turkey are characterized by occurrence of sympatric wild progenitor—domesticated forms of chickpea (and likewise cereals and other grain legumes). Therefore, both the authentic crop landraces and the wild populations native to the area are a unique genetic resource. Our results grant support to the notion of domestication within the natural distribution range of the wild progenitor, suggesting that the Neolithic domesticators were fully capable of selecting the desired phenotypes even when facing rare wild-domesticated introgression events.     

Does day-3 LH/FSH ratio influence in vitro fertilization outcome in PCOS patients undergoing controlled ovarian hyperstimulation with different GnRH-analogue?

In an attempt to evaluate whether high basal day-3 luteinizing hormone/follicle-stimulating hormone (LH/FSH) ratio affects IVF cycle outcome in polycystic ovary syndrome (PCOS) patients undergoing ovarian stimulation with either GnRH-agonist (n = 47) or antagonist (n = 104), we studied 151 IVF cycles: 119 in patients with basal LH/FSH <2 and 32 in patients with LH/FSH ≥ 2. The PCOS with high LH/FSH ratio achieved a non-significantly higher pregnancy rate using the GnRH-agonist (50% vs 17.9%, p = 0.2; respectively), as compared to the GnRH-antagonist protocols, probably due to the ability of the long GnRH-agonist protocol to induce a prolong and sustained reduction of the high basal LH milieu and avert its detrimental effect on oocyte quality and implantation potential.     

Cell proliferation and cooperation of v-mil and v-myc oncogenes

Retroviruses which possess the property to recombine with genetic material from the cell, have cloned and activated some oncogenes and hence are a privileged source for the study of these genes. Cellular oncogene activation can occur following two non mutually exclusive ways: (i) by over-expression of their products; (ii) by modifications of their products through mutations. Retroviruses can combine these two ways of activation leading to the over-expression of a modified product. In this paper, we present results obtained in the study of MH2, a retrovirus containing two oncogenes. We have shown that the two oncogenes of MH2 (v-mil and v-myc) cooperate in vitro to transform neuroretina cells from chicken embryos. These cells which normally do not grow in a defined medium, are induced to proliferate and become transformed upon infection by MH2. Our data enabled us to show that in MH2 v-mil was responsible for the induction of proliferation and v-myc for the transformation of the proliferating cells. Using in vitro constructs we located two regions in the protein encoded by v-mil which are important for its mitogenic property. We have also cloned the cellular counterpart of v-mil and the study of its biological activity on neuroretina cells enabled us to propose a mechanism of activation of the cellular gene by truncation of its 5' part.