High-molecular-weight penicillin-binding proteins from membranes of bacilli

Mixtures of high-molecular-weight, cephalosporin-sensitive penicillin-binding proteins (PBPs) can be purified from Bacillus subtilis membranes by cephalosporin affinity chromatography (G. Kleppe and J. L. Strominger, J. Biol. Chem. 254:4856-4862, 1979). By appropriate modification of this technique, B. subtilis PBP 1 was purified to homogeneity, and a mixture of Bacillus stearothermophilus PBPs 1, 2, and 4 was isolated. [14C]penicillin-PBP complexes of high-molecular-weight PBPs purified from membranes of these two bacilli, after denaturation, were found to have chemical reactivities typical of the penicilloyl-serine derivative formed by D-alanine carboxypeptidase from B. stearothermophilus. Although enzymatic activity catalyzed by these and several other high-molecular-weight PBPs from gram-positive organisms has not been detected with cell wall-related substrates, a slow, enzymatic acylation of B. subtilis PBPs 1, 2ab, and 4 by [14C]-diacetyl-L-lysyl-D-alanyl-D-lactate was demonstrated. Further study is necessary to clarify the physiological relevance of the slow acylation by this analog of a natural cell wall biosynthetic intermediate.     

Genetic control of the glp system in Bacillus subtilis.

In pleiotropic negative glycerol utilization mutants (GlpPI mutants) of Bacillus subitilis, glycerol kinase and sn-glycerol 3-phosphate (G3P) dehydrogenase are noninducible. GlpPI mutants also fail to take up exogenous [14C]G3P. To study the regulation of the glp system in B. subtilis phenotypically, Glp+ revertants were isolated from GlpPI mutants. Four classes of revertants were identified: phenotypically, wild type; R1 type, which contains an informational suppressor, R2 type, which produced G3P dehydrogenase constitutively; and R3 type, with a temperature-sensitive Glp phenotype producing G3P dehydrogenase constitutively at permissive temperature (32 degrees C). The properties of the revertants indicate that the glpPI locus codes for a protein with a positive regulatory function.     

snoRNPs Regulate Telomerase Activity in Neuroblastoma and Are Associated with Poor Prognosis

Amplification of the MYCN oncogene is strongly associated with poor prognosis in neuroblastoma (NB). In addition to MYCN amplification, many studies have focused on identifying patients with a poor prognosis based on gene expression profiling. The majority of prognostic signatures today are comprised of large gene lists limiting their clinical application. In addition, although of prognostic significance,most of these signatures fail to identify cellular processes that can explain their relation to prognosis. Here, we determined prognostically predictive genes in a data set containing 251 NBs. Gene Ontology analysis was performed on significant genes with a positive hazard ratio to search for cellular processes associated with poor prognosis. An enrichment in ribonucleoproteins (RNPs) was found. Genes involved in the stabilization and formation of the central small nucleolar RNP (snoRNP) complex were scrutinized using a backward conditional Cox regression resulting in an snoRNP signature consisting of three genes: DKC1, NHP2, and GAR1. The snoRNP signature significantly and independently predicted prognosis when compared to the established clinical risk factors. Association of snoRNP protein expression and prognosis was confirmed using tissue microarrays. Knockdown of snoRNP expression in NB cell lines resulted in reduced telomerase activity and an increase in anaphase bridge frequency. In addition, in patient material, expression of the snoRNP complex was significantly associated with telomerase activity, occurrence of segmental aberrations, and expression-based measurements of chromosomal instability. Together, these results underscore the prognostic value of snoRNP complex expression in NB and suggest a role for snoRNPs in telomere maintenance and genomic stability.     

Functional diversity decreases with temperature in high elevation ant fauna

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Hepatopancreas and ovary are sites of vitellogenin synthesis as determined from partial cDNA encoding of vitellogenin in the marine shrimp,Penaeus vannamei

Summary

The site of yolk protein synthesis in crustaceans has long been a subject of controversy. A portion of the vitellogenin gene structure was reported recently in a freshwater giant prawn (Macrobrachium rosenbergii) and black tiger shrimp (Penaeus monodori), in which the hepatopancreas was confirmed to be the extraovarian site of vitellogenin synthesis. The ovary is also frequently reported to be the site of yolk protein synthesis in penaeid shrimp. The same PCR product was obtained using cDNA from the hepatopancreas or the ovary as a template. The deduced amino acid sequence of Vg in P. vannamei showed high identities of 57% and 78% with those from M. rosenbergii and P. monodon, respectively. The same location of the intron in the sequenced region of genomic DNA was also found between these three species. We therefore concluded that the hepatopancreas and ovary are sites of vitellogenin synthesis in P. vannamei. The partial structure of the vitellogenin gene is further presented.     

Oxygen-depleted surfaces: a new antifouling technology

A novel, non-toxic strategy to combat marine biofouling is presented. The technology is paint with additions of up to 43% of industrial protein. Through microbial degradation of the protein component, an oxygen-depleted layer rapidly forms in a 0.2 mm layer close to the paint surface. With the present paint formulations, a stable, O₂-depleted layer can persist for 16 weeks. Barnacle larvae (cyprids) did not settle on panels where oxygen saturation was <20%, and cyprids were killed when exposed to O₂-free water for more than 1 h. It is also shown that the O₂-depleted layer will rapidly reform (within 15 min) after exposure to turbulent flow. Field exposure of panels for 16 weeks showed that paint with protein reduced fouling by barnacles and bryozoans by 80% and close to 100%, respectively. The results suggest that this novel technology may be developed into a non-toxic alternative to copper-based antifouling paints, especially for pleasure boats in sensitive environments. There is clearly potential for further development of the paint formulation, and a full-scale test on a boat-hull suggested that service-life under realistic operations needs to be improved.     

Mass mortality of an asteriid starfish (Forcipulatida,Asteroidea, Echinodermata) from the late Maastrichtian (Late Cretaceous) of Morocco

Abstract: A mass occurrence, numbering tens of thousands of individuals in a single lens, belonging to a single species of asteroid, is described from the late Maastrichtian (Late Cetaceous) of Morocco. The lens of partially silicified asteroidal limestone is made up largely of fully articulated specimens of similar size and probably represents the mass mortality of a single recruitment. By comparison with mass strandings of the present‐day species Asterias rubens (Linnaeus), it can be inferred that a feeding swarm of individuals was swept into a submarine channel by either a storm or an exceptionally strong tidal current, and permanently buried. The genus and species are herein described as Cretasterias reticulatus gen. et sp. nov. The exceptional preservation of the material enables the identification of wreath organs (clusters of crossed pedicellariae set in a dermal pad around spines) for the first time in the fossil record. Comparison between extant Asteriidae, putative fossil asteriids and C. reticulatus provides ambiguous evidence of its affinities; it appears to display a combination of plesiomorphic and derived characters. It is shown that all Mesozoic forcipulatid asteroids described so far share a very simple arm construction (single row of adradial ossicles) unknown in adult extant Forcipulatida.     

Discovery of XEN445: A potent and selective endothelial lipase inhibitor raises plasma HDL-cholesterol concentration in mice

Endothelial lipase (EL) activity has been implicated in HDL metabolism and in atherosclerotic plaque development; inhibitors are proposed to be efficacious in the treatment of dyslipidemia related cardiovascular disease. We describe here the discovery of a novel class of anthranilic acids EL inhibitors. XEN445 (compound 13) was identified as a potent and selective EL inhibitor, that showed good ADME and PK properties, and demonstrated in vivo efficacy in raising plasma HDLc concentrations in mice.