O-glycosylation of protein subpopulations in alcohol-extracted rice proteins

Mucin-type O-glycosylation has been well characterized in mammalian systems but not in plants. In this study, the purified alcohol-soluble, non-reduced protein (prolamin) fraction from rice seed was investigated for the occurrence of O-linked oligosaccharides. As storage prolamins are unlikely to be O-glycosylated, any O-glycosylation found was likely to belong to co-extracted proteins, whether because of association with the protein body or solubility. SDS-PAGE and MS analyses revealed 14 and 16kDa protein families in fractions that bound to the lectins peanut agglutinin (PNA), Vicia villosa lectin (VVL) and Jacalin, indicative of the presence of O-linked saccharides. Enzymatic cleavage, fluorescent labeling and high-performance liquid chromatography (HPLC) analysis demonstrated a peak consistent with Gal-beta-(1-->3)-GalNAc, with similar MS/MS fragmentation. Additionally, upon chemical analysis, a GlcNAc-containing O-linked carbohydrate moiety was discovered. Protein blotting with anti-O-GlcNAc antibody (clone CTD110.6) was positive in a subpopulation of the 14kDa alcohol-soluble protein fraction, but a hot capping experiment was negative. Therefore, the GlcNAc residue in this case is unlikely to be terminal. Additionally, a positive reaction with CTD110.6mAb cannot be taken as absolute proof of O-GlcNAc modification and further confirmatory experiments should be employed. We hypothesize that O-glycosylation may contribute to protein functionality or regulation. Further investigation is required to identify the specific proteins with these modifications. This 'reverse' approach could lead to the identification of proteins involved in mRNA targeting, signaling, translation, anchoring or maintenance of translational quiescence and may be applied to germinating rice seed extracts for further elucidation of protein function and regulation.     

A novel cell immunoassay to measure survival of motor neurons protein in blood cells

Background  

The motor neuron degenerative disease spinal muscular atrophy (SMA) is the leading genetic cause of infant mortality and is caused by mutations in the survival of motor neurons (SMN) gene that reduce the expression levels of the SMN protein. A major goal of current therapeutic approaches is to increase SMN levels in SMA patients. The purpose of this study was to develop a reliable assay to measure SMN protein levels from peripheral blood samples.     

Operationalizing niche construction theory with stone tools

One of the greatest difficulties with evolutionary approaches in the study of stone tools (lithics) has been finding a mechanism for tying culture and biology in a way that preserves human agency and operates at scales that are visible in the archaeological record. The concept of niche construction, whereby organisms actively construct their environments and change the conditions for selection, could provide a solution to this problem. In this review, we evaluate the utility of niche construction theory (NCT) for stone tool archaeology. We apply NCT to lithics both as part of the “extended phenotype” and as residuals or precipitates of other niche‐constructing activities, suggesting ways in which archaeologists can employ niche construction feedbacks to generate testable hypotheses about stone tool use. Finally, we conclude that, as far as its applicability to lithic archaeology, NCT compares favorably to other prominent evolutionary approaches, such as human behavioral ecology and dual‐inheritance theory.     

Synthesis of insect pheromones: Improved method for the preparation of queen substance and royal jelly of honeybees Apis mellifera

The biological activity of pheromones stems from various applications, especially in the area of pest control and insect monitoring; however, the quantity of pure pheromones available from natural sources is often extremely limited, because individual insects contain only minute amounts of pheromone. As our contribution to the field of pheromone synthesis, here we present a novel approach for the preparation of two known pheromones, namely queen substance and royal jelly of honeybees Apis mellifera. Our method is based on the original applications of lithiated α-alkenylphosphoramido anions as excellent synthetic equivalents of homoenolate anions.     

Book Reviews

PALAEOBIOLOGY: A SYNTHESIS, Editors: D. E. G. Briggs and P. R. Crowther. Blackwell Scientific Publications, Oxford 1990.608 pp. ISBN 0 632 025255. £89.50.

EVOLUTION AND THE FOSSIL RECORD, by K. Allen and D. Briggs (Eds). 265 pp. Belhaven Press, London 1989. £25.

THE EMERGENCE OF ANIMALS: THE CAMBRIAN BREAKTHROUGH, by M.A.S. McMenamin and D.L.S. McMenamin, Columbia University Press, ISBN 0–231–06646–5‐ISBN 0–231–06647–3 (paperback). $35 Hardback, $17 paperback.

ORIGINS AND EVOLUTION OF THE ANTARCTIC BIOTA, by JA. Crame (Ed.), Geological Soc. special publication n° 47, 322 pp. London. Price: £58.     

Advances in understanding the peptide neurotransmitter NAAG and appearance of a new member of the NAAG neuropeptide family

A substantial body of data was reported between 1984 and 2000 demonstrating that the neuropeptide N-acetylaspartylglutamate (NAAG) not only functions as a neurotransmitter but also is the third most prevalent transmitter in the mammalian nervous system behind glutamate and GABA. By 2005, this conclusion was validated further through a series of studies in vivo and in vitro. The primary enzyme responsible for the inactivation of NAAG following its synaptic release had been cloned, characterized and knocked out. Potent inhibitors of this enzyme were developed and their efficacy has been extensively studied in a series of animal models of clinical conditions, including stroke, peripheral neuropathy, traumatic brain injury, inflammatory and neuropathic pain, cocaine addiction, and schizophrenia. Considerable progress also has been made in defining further the mechanism of action of these peptidase inhibitors in elevating synaptic levels of NAAG with the consequent inhibition of transmitter release via the activation of pre-synaptic metabotropic glutamate receptor 3 by this peptide. Very recent discoveries include identification of two different nervous system enzymes that mediate the synthesis of NAAG from N-acetylaspartate and glutamate and the finding that one of these enzymes also mediates the synthesis of a second member of the NAAG family of neuropeptides, N-acetylaspartylglutamylglutamate.     

<Emphasis Type="Italic">O</Emphasis>-GlcNAcylation of the <Emphasis Type="Italic">Plum pox virus</Emphasis> capsid protein catalyzed by SECRET AGENT: characterization of <Emphasis Type="Italic">O</Emphasis>-GlcNAc sites by electron transfer dissociation mass spectrometry

The capsid protein of Plum pox virus (PPV-CP) is modified with O-linked β-N-acetylglucosamine (O-GlcNAc). In Arabidopsis thaliana this modification is made by an O-GlcNAc transferase named SECRET AGENT (SEC). Modification of PPV-CP by SEC is hypothesized to have a direct role in the infection process, because virus titer and rate of spread are reduced in SEC mutants. Previous studies used deletion mapping and site-directed mutagenesis to identify four O-GlcNAc sites on the capsid protein that are modified by Escherichia coli-expressed SEC. The infection process was not affected when two of these sites were mutated suggesting that O-GlcNAcylation of these sites does not have a significant role in the infection process or that a subset of the modifications is sufficient. Since it is possible that the mutational mapping approach missed or incorrectly identified O-GlcNAc sites, the modifications produced by E. coli-expressed SEC were characterized using mass spectrometry. O-GlcNAcylated peptides were enzymatically tagged with galactose, the products were enriched on immobilized Ricinus communis agglutinin I and sequenced by electron transfer dissociation (ETD) mass spectrometry. Five O-GlcNAc sites on PPV-CP were identified. Two of these sites were not identified in by the previous mutational mapping. In addition, one site previously predicted by mutation mapping was not detected, but modification of this site was not supported when the mutation mapping was repeated. This study suggests that mapping modification sites by ETD mass spectrometry is more comprehensive and accurate than mutational mapping.     

Dr. Auzoux's botanical teaching models and medical education at the universities of Glasgow and Aberdeen

In the 1860s, Dr. Louis Thomas Jérôme Auzoux introduced a set of papier-mâché teaching models intended for use in the botanical classroom. These botanical models quickly made their way into the educational curricula of institutions around the world. Within these institutions, Auzoux’s models were principally used to fulfil educational goals, but their incorporation into diverse curricula also suggests they were used to implement agendas beyond botanical instruction. This essay examines the various uses and meanings of Dr. Auzoux’s botanical teaching models at the universities of Glasgow and Aberdeen in the nineteenth century. The two main conclusions of this analysis are: (1) investing in prestigious scientific collections was a way for these universities to attract fee-paying students so that better medical accommodation could be provided and (2) models were used to transmit different kinds of botanical knowledge at both universities. The style of botany at the University of Glasgow was offensive and the department there actively embraced and incorporated ideas of the emerging new botany. At Aberdeen, the style of botany was defensive and there was some hesitancy when confronting new botanical ideas.     

Evaluation of DNA double strand breaks repair efficiency in head and neck cancer

Head and neck cancers (head and neck squamous cell carcinomas [HNSCC]) are a heterogeneous group of neoplasms with varying presenting symptoms, treatment, and expected outcome. There is a need to find an effective way of its treatment at the molecular level. Thus, we should identify the mechanism of cancer cell response to damaging agents' activity, especially at DNA level. Our major goal was to evaluate the efficacy of DNA double strand breaks (DSBs) repair in HTB-43 and SCC-25 cancer cell lines as well as lymphocytes taken from HNSCC patients and healthy donors. The DNA repair efficiency was measured by neutral comet assay as well as extrachromosomal assay for DNA DSBs repair (TAK assay). We determined the levels of two main pathways of DNA DSBs-nonhomologous end joining (NHEJ) and homologous recombination repair (HRR). Neutral comet assay was used for evaluation of DNA DSBs repair after treatment with genotoxic agents. DNA DSBs induced by gamma radiation were repaired slower in lymphocytes from HNSCC patients than in lymphocytes from healthy controls. HTB-43 and SCC-25 cancer cell lines have higher efficacy of NHEJ and HRR than lymphocytes taken from patients as well as control subjects. Our results confirm the necessity of further studies on the mechanisms of DNA DSBs repair to provide insight into the molecular basis of head and neck cancer, which will allow us to improve methods of HNSCC treatment.