Study of cholinesterases of different origin by the method of inhibitor analysis (variation of structure of phosphoryl and leaving parts of dialkoxyphosphates)

Analytical review is performed of literature data on inhibitor analysis of structure of cholinesterases from different animals (vertebrates, insects, molluscs) by studying rate of their interaction with 190 dialkoxyphosphates of 54 homologous series with regularly changed structure of their phosphoryl group. The presented data are discussed from the point of view of comparative biochemistry and in the light of current concepts of structure of cholinesterase active center in animals at different levels of evolutionary development.     

The carboxylesterase/cholinesterase gene family in invertebrate deuterostomes

Carboxylesterase/cholinesterase family members are responsible for controlling the nerve impulse, detoxification and various developmental functions, and are a major target of pesticides and chemical warfare agents. Comparative structural analysis of these enzymes is thus important. The invertebrate deuterostomes (phyla Echinodermata and Hemichordata and subphyla Urochordata and Cephalochordata) lie in the transition zone between invertebrates and vertebrates, and are thus of interest to the study of evolution. Here we have investigated the carboxylesterase/cholinesterase gene family in the sequenced genomes of Strongylocentrotus purpuratus (Echinodermata), Saccoglossus kowalevskii (Hemichordata), Ciona intestinalis (Urochordata) and Branchiostoma floridae (Cephalochordata), using sequence analysis of the catalytic apparatus and oligomerisation domains, and phylogenetic analysis. All four genomes show blurring of structural boundaries between cholinesterases and carboxylesterases, with many intermediate enzymes. Non-enzymatic proteins are well represented. The Saccoglossus and Branchiostoma genomes show evidence of extensive gene duplication and retention. There is also evidence of domain shuffling, resulting in multidomain proteins consisting either of multiple carboxylesterase domains, or of carboxylesterase/cholinesterase domains linked to other domains, including RING finger, chitin-binding, immunoglobulin, fibronectin type 3, CUB, cysteine-rich-Frizzled, caspase activation and 7tm-1, amongst others. Such gene duplication and domain shuffling in the carboxylesterase/cholinesterase family appears to be unique to the invertebrate deuterostomes, and we hypothesise that these factors may have contributed to the evolution of the morphological complexity, particularly of the nervous system and neural crest, of the vertebrates.     

Biotope prioritisation in the Central Apennines (Italy): species rarity and cross-taxon congruence

The conservation status of invertebrates is usually lesser known than that of vertebrates, and strategies to identify biotopes to preserve invertebrate diversity are typically based on a single surrogate taxon, or even on the use of vertebrates as surrogates. Aim of this research is to illustrate a method for biotope prioritisation that can be easily adapted to different animal groups and geographical contexts. A two-step protocol for biotope prioritisation is proposed on the basis of a multidimensional characterisation of species vulnerability. Firstly, species vulnerability is estimated from rarity measures which include geographical range, abundance and biotope specialisation. Then, these values of vulnerability are used to rank biotopes. The method was applied here to the tenebrionid beetles, the butterflies, the birds and the mammals of the Central Apennines, a montane area of high conservation concern for South Europe. This study provides evidence for the importance of including insects in conservation decisions, because vertebrates are poor surrogates for insects. Conservation efforts in the reserves included in the study area are mostly focused on vertebrates, for which woodlands are considered particularly important. However high altitude open biotopes are crucial for both tenebrionids and butterflies, and preservation of such kind of biotopes would be beneficial also for vertebrates. The approach applied here demonstrates that (1) vertebrates are poor surrogates for insects, and (2) measures of species rarity, typically used in vertebrate conservation, can be obtained also for insects, for which a veritable amount of data are hidden in specialised literature and museum collections.     

Sterols and their transport in animal development

The cellular content of different sterols in invertebrates and vertebrates as well as their origin (endogenous and food sources) and significance for the life cycle are comparatively reviewed. The initial signaling role of sterols in the vital activity (in all multicellular animals) and later obligatory incorporation of certain sterols in cell membranes as a plastic components (in vertebrates) are proposed based on the presented data.     

Sterols and their transport in animal development

The cellular content of different sterols in invertebrates and vertebrates as well as their origin (endogenous and food sources) and significance for the life cycle are comparatively reviewed. The initial signaling role of sterols in the vital activity (in all multicellular animals) and later obligatory incorporation of certain sterols in cell membranes as a plastic components (in vertebrates) are proposed based on the presented data.     

Inhibitor Analysis of Cholinesterases of Different Origin (Variation of Structure of Leaving Group of Organophosphorus Inhibitors)

There is presented an analytic review of literature data on inhibitory analysis of structure of cholinesterases of different animals (vertebrates, insects, and molluscs) performed by studying rate of their interaction with 64 organophosphorus compounds of 13 series with different structure of leaving group. The presented data are considered from the point of view of comparative biochemistry and in the light of current data on structure of the cholinesterase active center.__________Translated from Zhurnal Evolyutsionnoi Biokhimii i Fiziologii, Vol. 41, No. 3, 2005, pp. 201–216.Original Russian Text Copyright © 2005 by Moralev, Rozengart.     

Mannose-6-phosphate receptors (MPR 300 and 46) from the highly evolved invertebrate <Emphasis Type="Italic">Asterias rubens</Emphasis> (Echinodermate): biochemical and functional characterization of MPR 46 protein

Mammalian mannose 6-phosphate receptors (MPR 300 and 46) mediate transport of lysosomal enzymes to lysosomes. Recent studies established that the receptors are conserved throughout vertebrates. Although we purified the mollusc receptors and identified only a lysosomal enzyme receptor protein (LERP) in the Drosophila melanogaster, little is known about their structure and functional roles in the invertebrates. In the present study, we purified the putative receptors from the highly evolved invertebrate, starfish, cloned the cDNA for the MPR 46, and expressed it in mpr^(−/−) mouse embryonic fibroblast cells. Structural comparison of starfish receptor sequences with other vertebrate receptors gave valuable information on its extensive structural homology with the vertebrate MPR 46 proteins. The expressed protein efficiently sorts lysosomal enzymes within the cells establishing a functional role for this protein. This first report on the invertebrate MPR 46 further confirms the structural and functional conservation of the receptor not only in the vertebrates but also in the invertebrates.     

Ubiquitous presence of calciferin-like and cathepsin D-like activities in the sera (vertebrates) and humoral fluids (invertebrates)

1. Sera (or humoral fluids) from various animals (vertebrates and invertebrates) were assayed for calciferin-like and cathepsin D-like activities, indicating the ubiquitous presence of the latter and the former (with a few exceptions). Animals other than the mammals appeared to contain an organophilic calciferin-like activity in addition to a hydrophilic component (calciferin). 2. A correlation was found between the levels of calciferin and acid protease in most of the mammalian sera. An age-dependent decrease in calciferin (but not acid protease) was found in human sera. The possible presence of an acid protease-inhibitor was suggested.     

Different sensitivity of Ca(2+)-ATPase and cholinesterase to pure and commercial pesticides in nervous ganglia of Phyllocaulis soleiformis (Mollusca)

We measured the effects in vitro of pure and commercial pesticides on Ca(2+)-activated ATPase and cholinesterase (ChE) activities in the nervous system of the slug Phyllocaulis soleiformis. The pesticides used in this study included carbamate and organophosphates, which acts as reversible and irreversible anticholinesterases, respectively. Both enzymes were insensitive to pure carbofuran (1 mM), glyphosate (1 mM) and malathion (120 microM). However, the carbamate carbofuran, in the commercial formulation Furandan 350S, inhibited ATPase and ChE activities. The organophosphate glyphosate used in the commercial preparation of Gliz 480CS inhibited ATPase activity and increased cholinesterase activity. These effects are likely due to the action of adjuvant substances of the chemical formulation. The commercial formulation (Malatol 500CE) did not alter enzymes activities. Our results suggest that cholinesterase present in the slug nervous tissue has a different behavior to those identified in vertebrate nervous tissue, since it was insensitive to pure compounds, known as anticholinesterases in vertebrates. Considering the insensitivity of the Ca(2+)-activated ATPase, we suggested that the purinergic neurotransmission and other roles of ATP might not be affected by the pure pesticides tested.     

Emergence of Eucalyptus marginata (jarrah) from seed in Mediterranean-climate forest in response to overstorey,site, seedbed and seed harvesting

Abstract The effects of overstorey, type of site, seedbed, seeding date and seed harvesting by vertebrates and invertebrates on the emergence of Eucalyptus marginata (jarrah) seedlings were studied experimentally in the northern jarrah forest of Western Australia. Seed harvesting by small vertebrates substantially reduced emergence, whereas invertebrates only slightly reduced emergence. Ninety per cent of seed was removed within 1 day when it was on the soil surface and in the open, whereas seed removal was insignificant when the seed was covered by soil. Vertebrates harvested seed more effectively when the understorey and litter were removed and the seed was more visible on the soil surface. Seed harvesting by small vertebrates had less impact on a site where there had been bauxite mining, possibly because the surrounding area was being revegetated with large numbers of seed and the area afforded poor cover for vertebrates. Emergence was less where the overstorey was removed compared to where it was retained, and on the rehabilitated bauxite mined site compared to the forest sites. There was no difference in emergence between the low and high quality forest sites and so the emergence phase could not fully explain the variation in abundance off. marginata seedlings on different quality sites. Post emergence events are likely to be important in explaining this difference between low and high quality sites.     

Predator impacts on stream benthic prey

The impact that predators have on benthic, macroinvertebrate prey density in streams is unclear. While some studies show a strong effect of predators on prey density, others show little or no effect. Two factors appear to influence the detection of predator impact on prey density in streams. First, many field studies have small sample sizes and thus might be unable to detect treatment effects. Second, streams contain two broad classes of predators, invertebrates and vertebrates, which might have different impacts on prey density for a variety of reasons, including availability of refuge for prey and prey emigration responses to the two types of predators. In addition, predatory vertebrates have more complex prey communities than predatory invertebrates; this complexity might reduce the impact that predatory vertebrates have on prey because of indirect effects. I conducted a meta-analysis on the results of field studies that manipulate predator density in enclosures to determine (1) if predators have a significant impact on benthic prey density in streams, (2) if the impacts that predatory invertebrates and vertebrates have differ, and (3) if predatory vertebrates have different impacts on predatory prey versus herbivorous prey. The results of the meta-analysis suggest that on average predators have a significant negative effect on prey density, predatory invertebrates have a significantly stronger impact than predatory vertebrates, and predatory vertebrates do not differ in their impact on predatory versus herbivorous invertebrate prey. Three methodological variables (mesh size of enclosures, size of enclosures, and experimental duration) were examined to determine if cross correlations exist that may explain the differences in impact between predatory invertebrates and vertebrates. No correlation exists between mesh size and predator impact. Over all predators, no correlation exists between experimental duration and predator impact; however, within predatory invertebrates a correlation does exist between these variables. Also, a correlation was found between enclosure size and predator impact. This correlation potentially explains the difference in impact between predatory invertebrates and predatory vertebrates. Results of the meta-analysis suggest two important areas for future research: (1) manipulate both types of predators within the same system, and (2) examine their impacts on the same spatial scale.     

Numerous peptidoglycan recognition protein genes expressed in the bacteriome of the green rice leafhopper Nephotettix cincticeps (Hemiptera,Cicadellidae)

Applied Entomology and Zoology - Peptidoglycan recognition proteins (PGRPs) contribute to the immune response of vertebrates and higher invertebrates. Animals have a varying number of PGRP genes: 4...     

Anophthalmia and elongation of body appendages in cave scale worms (Annelida: Aphroditiformia)

This study addresses whether cave dwelling annelids exhibited similar reductive and constructive traits equally as strong as those of arthropods and vertebrates inhabiting caves. Known as troglomorphism, these adaptations bring about striking morphologies across invertebrates and vertebrates from both aquatic and terrestrial cave habitats, and include varying degrees of eye and pigmentation loss, as well as hypertrophy of body appendages and sensorial structures. Employing phylogenetic comparative methods and ancestral character reconstructions on a worldwide data set of a group of annelids, the scale worms (Aphroditiformia), we investigate the behavioural and morphological traits of species living in marine caves in comparison with those species living outside caves. Our work demonstrated that cave scale worms respond similar to arthropods in cave environments, showing a significant elongation of sensory parapodial cirri, while lacking eyes and pigmentation. However, whereas elongation of sensory appendages likely occurred in correlation to cave colonization, eyes were plausibly lost in correlation with specialization and colonization of deep‐sea habitats.     

Mites of the family Cheyletidae (Acari: Prostigmata): phylogeny, distribution, evolution and analysis of parasite-host relationship

A modern system, phylogeny, distribution and host parasite relationships of cheyletid mites (Acari: Prostigmatal Cheyletidae) is shortly discussed. According to the phylogenetic hypothesis proposed by Bochkov and Fain (2001), the family Cheyletidae includes now 15 tribes: Acaropsellini, Bakini, Cheletogenini, Cheletosomatini, Chelonotini, Cheyletiini, Cheyletiellini, Cheyletini, Cheletomorphini, Criokerontini, Metacheyletiini, Niheliini, Ornithocheyletiini, Teinocheylini and one unnamed tribe including the genera Caudacheles and Alliea. The parasitic Cheyletidae were primarily free-living predators, frequently associated with nests of vertebrates. These mites, being predators, have numerous preadaptations to the parasitic mode of life and they possess high ecological plasticity. Therefore it was quite easy for these mites to adapt to parasitism on the vertebrates. According to our phylogenetical hypothesis, the parasitism on vertebrates has arisen independently in several phylogenetic lines of the cheyletids associated with nests of vertebrates. Such transition from nest predation to true parasitism probably occurred repeatedly and at different times. The cheyletid mites are more widely represented on birds than on mammals. Possibly, it is in relation with a more early origin of parasitism in the cheyletids associated with bird nests than in the cheyletids associated with mammal nests. An independent origin of the parasitism in many different cheyletid phyletic lines, arisen significantly later than the origin of such a parasitic group as myobiid mites, is probably the main reason, which could explain the recent mosaic distribution of the Cheyletidae among the mammalian taxa. Parasitic associations between cheyletids and vertebrates are more common than the associations between these mites and the invertebrates. In the invertebrates, these associations are generally restricted to a phoresy. The zoogeographical analysis showed that this family as whole is characterised by the extremely low endemisms. The most part of the free-living cheyletid mites are associated with Holarctic region (87%) and, therefore, this family, probably, originated there.     

Endocrine disruptors in marine organisms: approaches and perspectives

Organic pollutants exhibiting endocrine disrupting activity (Endocrine Disruptors--EDs) are prevalent over a wide range in the aquatic ecosystems; most EDs are resistant to environmental degradation and are considered ubiquitous contaminants. The actual potency of EDs is low compared to that of natural hormones, but environmental concentrations may still be sufficiently high to produce detrimental biological effects. Most information on the biological effects and mechanisms of action of EDs has been focused on vertebrates. Here we summarize recent progress in studies on selected aspects of endocrine disruption in marine organisms that are still poorly understood and that certainly deserve further research in the near future. This review, divided in four sections, focuses mainly on invertebrates (effects of EDs and mechanisms of action) and presents data on top predators (large pelagic fish and cetaceans), a group of vertebrates that are particularly at risk due to their position in the food chain. The first section deals with basic pathways of steroid biosynthesis and metabolism as a target for endocrine disruption in invertebrates. In the second section, data on the effects and alternative mechanisms of action of estrogenic compounds in mussel immunocytes are presented, addressing to the importance of investigating full range responses to estrogenic chemicals in ecologically relevant invertebrate species. In the third section we review the potential use of vitellogenin (Vtg)-like proteins as a biomarker of endocrine disruption in marine bivalve molluscs, used worldwide as sentinels in marine biomonitoring programmes. Finally, we summarize the results of a recent survey on ED accumulation and effects on marine fish and mammals, utilizing both classical biomarkers of endocrine disruption in vertebrates and non-lethal techniques, such as non-destructive biomarkers, indicating the toxicological risk for top predator species in the Mediterranean. Overall, the reviewed data underline the potential to identify specific types of responses to specific groups of chemicals such as EDs in order to develop suitable biomarkers that could be useful as diagnostic tools for endocrine disruption in marine invertebrates and vertebrates.     

Evidence for a molecular polymorphis of cholinesterase in Sepia officinalis (cephalopoda: decapoda)

• 1.1. Three forms of cholinesterase were sequentially extracted from head and tentacles of Sepia officinalis and noted as low-salt (LSS), detergent (DS) and high-salt (HSS) soluble. They represent about 24, 30 and 46% of total activity.
• 2.2. All enzyme forms seem to be amphiphilic proteins with hydrophobic domains interacting with non-ionic detergent (Triton X-100) and giving self-aggregation (LSS form).
• 3.3. The DS form is membrane-anchored by a phosphatidylinositol, while the HSS form is likely linked to some proteoglycan molecule of the extracellular matrix by ionic interactions.
• 4.4. According to V_max/K_m values, all the enzymes are acetylcholinesterases, even if hydrolyze propionylthiocoline at the highest rate.
• 5.5. Some kinetic and molecular properties of the studied enzymes are compared with those of other cholinesterases from vertebrates and invertebrates. Possible phylogenic and adaptive features are discussed.

     

Three rounds (1R/2R/3R) of genome duplications and the evolution of the glycolytic pathway in vertebrates

Background  

Evolution of the deuterostome lineage was accompanied by an increase in systematic complexity especially with regard to highly specialized tissues and organs. Based on the observation of an increased number of paralogous genes in vertebrates compared with invertebrates, two entire genome duplications (2R) were proposed during the early evolution of vertebrates. Most glycolytic enzymes occur as several copies in vertebrate genomes, which are specifically expressed in certain tissues. Therefore, the glycolytic pathway is particularly suitable for testing theories of the involvement of gene/genome duplications in enzyme evolution.     

Evolutionary History of the GABA Transporter (GAT) Group Revealed by Marine Invertebrate GAT-1

The GABA transporter (GAT) group is one of the major subgroups in the solute career 6 (SLC6) family of transmembrane proteins. The GAT group, which has been well studied in mammals, has 6 known members, i.e., a taurine transporter (TAUT), four GABA transporters (GAT-1, -2, -3, - 4), and a creatine transporter (CT1), which have important roles in maintaining physiological homeostasis. However, the GAT group has not been extensively investigated in invertebrates; only TAUT has been reported in marine invertebrates such as bivalves and krills, and GAT-1 has been reported in several insect species and nematodes. Thus, it is unknown how transporters in the GAT group arose during the course of animal evolution. In this study, we cloned GAT-1 cDNAs from the deep-sea mussel, Bathymodiolus septemdierum, and the Antarctic krill, Euphausia superba, whose TAUT cDNA has already been cloned. To understand the evolutionary history of the GAT group, we conducted phylogenetic and synteny analyses on the GAT group transporters of vertebrates and invertebrates. Our findings suggest that transporters of the GAT group evolved through the following processes. First, GAT-1 and CT1 arose by tandem duplication of an ancestral transporter gene before the divergence of Deuterostomia and Protostomia; next, the TAUT gene arose and GAT-3 was formed by the tandem duplication of the TAUT gene; and finally, GAT-2 and GAT-4 evolved from a GAT-3 gene by chromosomal duplication in the ancestral vertebrates. Based on synteny and phylogenetic evidence, the present naming of the GAT group members does not accurately reflect the evolutionary relationships.     

Role of gangliosides in the processes of calcium ion transport across the membranes of nerve cells

It has been demonstrated that the content of extracellular Ca in the nervous system is inversely related to the content of gangliosides. The results obtained on invertebrates, lower and higher vertebrates indicate that the highest content of extracellular Ca is typical of the nervous tissue of invertebrates, whereas the lower one--of the nervous tissue of higher vertebrates (mammals). Ganglioside content, on the contrary, is the highest in the brain tissue of the higher vertebrates (mammals and birds), being significantly lower in lower vertebrates; no gangliosides was found at all in the nervous tissue of protostomian invertebrates. The highest ganglioside content in the organism of vertebrates is characteristic to the surface membranes of the nervous cells, especially in the region of synapses. Functional significance of the inverse relationship between the content of extracellular Ca and gangliosides is discussed from the standpoint of one of the authors (R. Veh) who postulated the existence of calcium--ganglioside buffer in the vicinity of the surface of the nervous cells.