Transmembrane and Coiled-Coil Domain Family 1 Is a Novel Protein of the Endoplasmic Reticulum

The endoplasmic reticulum (ER) is a continuous membrane network in eukaryotic cells comprising the nuclear envelope, the rough ER, and the smooth ER. The ER has multiple critical functions and a characteristic structure. In this study, we identified a new protein of the ER, TMCC1 (transmembrane and coiled-coil domain family 1). The TMCC family consists of at least 3 putative proteins (TMCC1–3) that are conserved from nematode to human. We show that TMCC1 is an ER protein that is expressed in diverse human cell lines. TMCC1 contains 2 adjacent transmembrane domains near the C-terminus, in addition to coiled-coil domains. TMCC1 was targeted to the rough ER through the transmembrane domains, whereas the N-terminal region and C-terminal tail of TMCC1 were found to reside in the cytoplasm. Moreover, the cytosolic region of TMCC1 formed homo- or hetero-dimers or oligomers with other TMCC proteins and interacted with ribosomal proteins. Notably, overexpression of TMCC1 or its transmembrane domains caused defects in ER morphology. Our results suggest roles of TMCC1 in ER organization.     

On the specificity of caffeine effects

Summary Caffeine in 0.1% or higher concentration reversibly inhibits E. coli and yeast growth. It inhibits RNA and protein synthesis (Tables 1+3) within a few minutes after being added to the incubation medium (Fig. 2). The suggestion is made that these effects of caffeine, as well as its synergism with some mutagens, are due to its ability to costack with free purines and to form complexes with single-stranded nucleic acids.     

Threshold levels of maternal nicotine impairing protective responses of newborn rats to intermittent hypoxia.

Experiments were carried out to determine the threshold level of maternal nicotine that impairs protective responses of rat pups to hypoxia. From days 6 or 7 of gestation, pregnant rats received either vehicle or nicotine (1.50, 3.00, or 6.00 mg of nicotine tartrate. kg body wt(-1).day(-1)) or vehicle continuously via a subcutaneous osmotic minipump. On postnatal days 5 or 6, pups were exposed to a single period of hypoxia produced by breathing an anoxic gas mixture (97% N(2) or 3% CO(2)) and their time to last gasp was determined, or they were exposed to intermittent hypoxia and their ability to autoresuscitate from hypoxic-induced primary apnea was determined. Perinatal exposure to nicotine did not alter the time to last gasp or the total number of gasps when the pups were exposed to a single period of hypoxia. The number of successful autoresuscitations on repeated exposure to hypoxia was, however, decreased in pups whose dams had received either 3.00 or 6.00 mg of nicotine tartrate/kg body wt; these dosage regimens produced maternal serum nicotine concentrations of 19 +/- 6 and 35 +/- 8 ng/ml, respectively. Thus our experiments define the threshold level of maternal nicotine that significantly impairs protective responses of 5- to 6-day-old rat pups to intermittent hypoxia such as may occur in human infants during episodes of prolonged sleep apnea or positional asphyxia.     

Plasmidome Interchange between Clostridium botulinum,Clostridium novyi and Clostridium haemolyticum Converts Strains of Independent Lineages into Distinctly Different Pathogens

Clostridium botulinum (group III), Clostridium novyi and Clostridium haemolyticum are well-known pathogens causing animal botulism, gas gangrene/black disease, and bacillary hemoglobinuria, respectively. A close genetic relationship exists between the species, which has resulted in the collective term C. novyi sensu lato. The pathogenic traits in these species, e.g., the botulinum neurotoxin and the novyi alpha toxin, are mainly linked to a large plasmidome consisting of plasmids and circular prophages. The plasmidome of C. novyi sensu lato has so far been poorly characterized. In this study we explored the genomic relationship of a wide range of strains of C. novyi sensu lato with a special focus on the dynamics of the plasmidome. Twenty-four genomes were sequenced from strains selected to represent as much as possible the genetic diversity in C. novyi sensu lato. Sixty-one plasmids were identified in these genomes and 28 of them were completed. The genomic comparisons revealed four separate lineages, which did not strictly correlate with the species designations. The plasmids were categorized into 13 different plasmid groups on the basis of their similarity and conservation of plasmid replication or partitioning genes. The plasmid groups, lineages and species were to a large extent entwined because plasmids and toxin genes had moved across the lineage boundaries. This dynamic process appears to be primarily driven by phages. We here present a comprehensive characterization of the complex species group C. novyi sensu lato, explaining the intermixed genetic properties. This study also provides examples how the reorganization of the botulinum toxin and the novyi alpha toxin genes within the plasmidome has affected the pathogenesis of the strains.     

Pharmacological studies on the pulmonary vein of the horse. I. Effects of selected spasmogens.

Horses suffer from a respiratory condition, similar to human allergic asthma, that is characterized by severe dyspnea, wheezing, coughing, and mucus production. Mediator substances released during the allergic reaction may contract airways and pulmonary vasculature. Nothing is known of the effects of autacoids and other vasoactive substances on equine pulmonary vessels. Therefore, spiral strips of equine pulmonary vein were prepared in vitro and the effects of histamine (H), 5-hydroxytryptamine (5HT), bradykinin (BK), carbachol (Carb), and phenylephrine (phen) were studied. The order of contractile effectiveness for the agonists on the vein was found to be 5HT greater than H greater than Bk greater than Phen greater than Carb, although H consistently produced the greatest maximal effects. H1-receptors appeared to mediate H contractions while H2-receptors had no measurable effect. 5HT responses were mediated directly by 'D-type' smooth muscle receptors. Bk produced contractions but of a lesser magnitude than either H or 5HT. Varying degrees of tachyphylaxis were observed for each agent. alpha-Adrenergic receptor stimulation by Phen initiated low-magnitude contractions whereas Carb exhibited virtually no activity on the pulmonary vein. Contractile responses of pulmonary veins to various spasmogens may contribute to the equine asthmatic response by raising vascular hydrostatic pressure, thereby enhancing edema formation.     

Effect of specific trifluoroacetylation of individual cytochrome c lysines on the reaction with cytochrome oxidase.

We have prepared three different cytochrome c derivatives, each containing a single specifically trifluoroacetylated lysine at residues 13, 55, and 99, respectively. The only modification that affected cytochrome c oxidase (EC 1.9.3.1) activity was that of lysine-13 at the top of the heme crevice. Trifluoroacetylation of lysine-13 increased the apparent Michaelis constant fivefold compared to that of native cytochrome c, but did not affect the maximum velocity. Trifluoroacetylation of lysine-55 at the left side of the cytochrome c molecule did not affect cytochrome oxidase activity in any way, nor did trifluoroacetylation of lysine-99 at the rear of the cytochrome c molecule. This indicates that the cytochrome oxidase binding site on cytochrome c involved only the front of the cytochrome c molecule and those lysines immediately surrounding the heme crevice.     

Chemotactic response of wild-type and aggregation-defective mutants of Polysphondylium violaceum

Abstract. The aggregation-specific chemoattractant for Polysphondylium violaceum is N-propionyl-γ-L-glutamyl-L-ornithine-δ-lactam ethyl ester, or glorin. Wild-type amoebae allowed to develop in liquid culture acquire increased ability to respond to glorin shortly after starvation, i.e., just prior to the time they become aggregation competent. Similarly, as development proceeds, the amoebae show decreased sensitivity to folic acid, but they show almost no response to cyclic AMP at any time during their development in liquid culture. The optimum concentrations for the chemotactic response are 10^-8 M for glorin and 10^-5–10^-6 M for folic acid. A class of aggregation-defective mutants, aggA , will not aggregate in the absence of an excreted pheromone, D factor. During development in liquid culture in the presence or absence of D factor, these aggA mutants show a chemotactic response similar to that of wild-type amoebae to folic acid and glorin. However, D factor does enhance the chemotactic response of aggA mutants to glorin. In the absence of D factor, mutant amoebae will form fruiting bodies if exposed to a chemotactic gradient of either folic acid or glorin. Under these conditions, the mutant amoebae circumvent the requirement for D factor in order to develop.     

Immuno-electron-microscopic localization of types III pN-collagen and IV collagen,laminin and tenascin in developing and adult human spleen

The distribution of the extracellular matrix proteins types III pN-collagen and IV collagen, laminin and tenascin was investigated in fetal, infant, and adult human spleens by using immuno-electron microscopy. The presence of type III pN-collagen was assessed by using an antibody against the aminoterminal propeptide of type III procollagen. All the proteins other than type III pN-collagen were found in reticular fibers throughout development. In the white pulp of the fetus aged 16 gestational weeks, only an occasional type III pN-collagen-containing fibril was present, although type III pN-collagen was abundant in the reticular fibers of the red pulp. Conversely, in adults, most of the reticular fibers of the white pulp, but not of the red pulp, were immunoreactive for type III pN-collagen. Ring fibers, the basement membranes of venous sinuses, were well developed in both infant and adult spleens. The first signs of their formation could be seen as a discontinuous basement membrane, which was immunoreactive for type IV collagen, laminin, and tenascin in the fetus aged 20 gestational weeks. Intracytoplasmic immunoreactivity for all the proteins studied was visible in the mesenchymal cells of the fetus aged 16 gestational weeks and in the reticular cells of the older fetuses, which also showed labeling for type IV collagen and laminin in the endothelial cells. The results suggest that proteins of the extracellular matrix are produced by these stationary cells.     

Nutrients Limiting Soybean (glycine max l) Growth in Acrisols and Ferralsols of Western Kenya

Low soybean yields in western Kenya have been attributed to low soil fertility despite much work done on nitrogen (N) and phosphorus (P) nutrition leading to suspicion of other nutrient limitations. To investigate this, a nutrient omission trial was set up in the greenhouse at the University of Eldoret-Kenya to diagnose the nutrients limiting soybean production in Acrisols from Masaba central and Butere sub-Counties, and Ferralsols from Kakamega (Shikhulu and Khwisero sub-locations) and Butula sub-Counties and to assess the effect of liming on soil pH and soybean growth. The experiment was laid out in a completely randomized design with ten treatments viz; positive control (complete), negative control (distilled water), complete with lime, complete with N, minus macronutrients P, potassium (K), calcium (Ca), magnesium (Mg) and sulphur (S) and with, micro-nutrients boron (B), molybdenum (Mo), manganese (Mn), copper (Cu) and zinc (Zn) omitted. Visual deficiency symptoms observed included interveinal leaf yellowing in Mg omission and N addition and dark green leaves in P omission. Nutrients omission resulted in their significantly low concentration in plant tissues than the complete treatment. Significantly (P≤ 0.05) lower shoot dry weights (SDWs) than the complete treatment were obtained in different treatments; omission of K and Mg in Masaba and Shikhulu, Mg in Khwisero, K in Butere and, P, Mg and K in Butula. Nitrogen significantly improved SDWs in soils from Kakamega and Butula. Liming significantly raised soil pH by 9, 13 and 11% from 4.65, 4.91 and 4.99 in soils from Masaba, Butere and Butula respectively and soybean SDWs in soils from Butere. The results show that, poor soybean growth was due to K, Mg and P limitation and low pH in some soils. The results also signify necessity of application of small quantities of N for initial soybean use.