Characterization of Arthrobacter nicotinovorans HIM, an atrazine-degrading bacterium, from agricultural soil New Zealand

Arthrobacter nicotinovorans HIM was isolated directly from an agricultural sandy dune soil 6 months after a single application of atrazine. It grew in minimal medium with atrazine as sole nitrogen source but was unable to mineralize 14C-ring-labelled atrazine. Atrazine was degraded to cyanuric acid. In addition to atrazine the bacterium degraded simazine, terbuthylazine, propazine, cyanazine and prometryn but was unable to grow on terbumeton. When added to soil, A. nicotinovorans HIM did enhance mineralization of 14C-ring-labelled atrazine and simazine, in combination with naturally occurring cyanuric acid degrading microbes resident in the soil. Using PCR, the atrazine-degradation genes atzABC were identified in A. nicotinovorans HIM. Cloning of the atzABC genes revealed significant homology (>99%) with the atrazine degradation genes of Pseudomonas sp. strain ADP. The atrazine degradation genes were held on a 96 kbp plasmid.     

A preliminary study of the metabolic stability of a series of benzoxazinone derivatives as potent neuropeptide Y5 antagonists

The metabolic stability of benzoxazinone derivatives, a potent series of NPY Y5 antagonists, has been investigated. This study resulted in the identification of the structural moieties prone to metabolic transformations and which strongly influenced the in vitro half-life. This provides opportunities to optimize the structure of this new class of NPY Y5 antagonists.     

Global trends in world fisheries: impacts on marine ecosystems and food security

This contribution, which reviews some broad trends in human history and in the history of fishing, argues that sustainability, however defined, rarely if ever occurred as a result of an explicit policy, but as result of our inability to access a major part of exploited stocks. With the development of industrial fishing, and the resulting invasion of the refuges previously provided by distance and depth, our interactions with fisheries resources have come to resemble the wars of extermination that newly arrived hunters conducted 40,000-50,000 years ago in Australia, and 11,000-13,000 years ago against large terrestrial mammals arrived in North America. These broad trends are documented here through a map of change in fish sizes, which displays characteristic declines, first in the nearshore waters of industrialized countries of the Northern Hemisphere, then spread offshore and to the Southern Hemisphere. This geographical extension met its natural limit in the late 1980s, when the catches from newly accessed stocks ceased to compensate for the collapse in areas accessed earlier, hence leading to a gradual decline of global landing. These trends affect developing countries more than the developed world, which have been able to meet the shortfall by increasing imports from developing countries. These trends, however, together with the rapid growth of farming of carnivorous fishes, which consumes other fishes suited for human consumption, have led to serious food security issues. This promotes urgency to the implementation of the remedies traditionally proposed to alleviate overfishing (reduction of overcapacity, enforcement of conservative total allowable catches, etc.), and to the implementation of non-conventional approaches, notably the re-establishment of the refuges (also known as marine reserves), which made possible the apparent sustainability of pre-industrial fisheries.     

The immunomodulatory protein B7-H4 is overexpressed in breast and ovarian cancers and promotes epithelial cell transformation

B7-H4 protein is expressed on the surface of a variety of immune cells and functions as a negative regulator of T cell responses. We independently identified B7-H4 (DD-O110) through a genomic effort to discover genes upregulated in tumors and here we describe a new functional role for B7-H4 protein in cancer. We show that B7-H4 mRNA and protein are overexpressed in human serous ovarian cancers and breast cancers with relatively little or no expression in normal tissues. B7-H4 protein is extensively glycosylated and displayed on the surface of tumor cells and we provide the first demonstration of a direct role for B7-H4 in promoting malignant transformation of epithelial cells. Overexpression of B7-H4 in a human ovarian cancer cell line with little endogenous B7-H4 expression increased tumor formation in SCID mice. Whereas overexpression of B7-H4 protected epithelial cells from anoikis, siRNA-mediated knockdown of B7-H4 mRNA and protein expression in a breast cancer cell line increased caspase activity and apoptosis. The restricted normal tissue distribution of B7-H4, its overexpression in a majority of breast and ovarian cancers and functional activity in transformation validate this cell surface protein as a new target for therapeutic intervention. A therapeutic antibody strategy aimed at B7-H4 could offer an exciting opportunity to inhibit the growth and progression of human ovarian and breast cancers.     

C-terminal sequencing by mass spectrometry: application to gelatine-derived proline-rich peptides

Protonated peptides derived from proline‐rich proteins (PRP) are often difficult to sequence by standard collision‐induced dissociation (CID) mass spectrometry (MS) due to preferential amide bond cleavage N‐terminal to proline. In connection with bovine spongiform encephalopathy regulations, proteolytic products derived from the PRP collagen have been suggested as markers for contamination of animal feedstuffs with processed animal protein (Fernandez Ocaña, M. et al., Analyst 2004, 129, 111–115). Herein, we report the identification of these marker peptides using the strategy of C‐terminal sequencing by CID MS from their sodium and lithium adducts. Upon fragmentation a new cationized peptide was produced that is one C‐terminal amino acid shorter in length. This dissociation pathway allowed for the facile identification of the C‐terminal residue by matrix‐assisted laser desorption/ionization tandem time‐of‐flight mass spectrometry. Each newly formed cationized peptide was further fragmented by up to seven stages of electrospray ionization ion trap MS. Proline‐rich C‐terminal sequence tags were established which permitted successful database identification of collagen alpha type I proteins.     

A novel phosphatidylinositol manno-oligosaccharide (dPIM-8) from Gordonia sputi

The deacylated phosphatidylinositol manno-oligosaccharides (dPIMs) from the glycosyl phosphatidylinositol (GPI) carbohydrate antigen anchor of Gordonia sputi were the known 2,6-di-O-alpha-mannopyranosyl-myo-inositol glycerophosphate (dPIM-2) and the illustrated novel compound (dPIM-8), which could not be separated from dPIM-7 and dPIM-6, these three compounds being present in the mixture in the molar ratios 1.0:0.65:0.4. dPIM-8 is an analogue of dPIM-2 (and also of dPIM-7 and dPIM-6) in having alpha-mannopyranose and an alpha-mannopyranosyl linked heptasaccharide bonded to O-2 and O-6, respectively, of the inositol. The dPIM-8 species has not been found previously. [structure: see text]     

An alternative splicing product of the murine trpv1 gene dominant negatively modulates the activity of TRPV1 channels

Transient receptor potential vanilloid 1 (TRPV1), or vanilloid receptor 1, is the founding member of the vanilloid type of TRP superfamily of nonselective cation channels. TRPV1 is activated by noxious heat, acid, and alkaloid irritants as well as several endogenous ligands and is sensitized by inflammatory factors, thereby serving important functions in detecting noxious stimuli in the sensory system and pathological states in different parts of the body. Whereas numerous studies have been carried out using the rat and human TRPV1 cDNA, the mouse TRPV1 cDNA has not been characterized. Here, we report molecular cloning of two TRPV1 cDNA variants from dorsal root ganglia of C57BL/6 mice. The deduced proteins are designated TRPV1alpha and TRPV1beta and contain 839 and 829 amino acids, respectively. TRPV1beta arises from an alternative intron recognition signal within exon 7 of the trpv1 gene. We found a predominant expression of TRPV1alpha in many tissues and significant expression of TRPV1beta in dorsal root ganglia, skin, stomach, and tongue. When expressed in HEK 293 cells or Xenopus oocytes, TRPV1alpha formed a Ca(2+)-permeable channel activated by ligands known to stimulate TRPV1. TRPV1beta was not functional by itself but its co-expression inhibited the function of TRPV1alpha. Furthermore, although both isoforms were synthesized at a similar rate, less TRPV1beta than TRPV1alpha protein was found in cells and on the cell surface, indicating that the beta isoform is highly unstable. Our data suggest that TRPV1beta is a naturally occurring dominant-negative regulator of the responses of sensory neurons to noxious stimuli.