Using DNA barcodes to test the association of sexes and morphs in Calodesma spp. (Lepidoptera, Erebidae, Arctiinae, Arctiini, Pericopina) of Trinidad, West Indies, with an overview of the genus, taxonomic changes and a new species.

Phalaena militta Stoll, [1781], currently in the combination Thyrgis militta, is transferred to the new combination Calodesma militta. Phalaena militta is the type species of Thyrgis Walker, 1854, and so Thyrgis is a junior synonym of Calodesma Hübner, [1820]. The reinstated genus Seileria Dognin, 1923 is the next available name for the genus previously known as Thyrgis, and the remaining eight species and their subspecies currently in Thyrgis are transferred to new combinations as species of Seileria: S. angustifascia (Hering, 1925), S. basipunctata (Hering, 1926), S. constrictifascia (Dognin, 1919), S. flavonigra (Dognin, 1910), S. investigatorum (Toulgoët, 1988), S. marginata (Butler, 1875), S. meres (Druce, 1911), S. phlegon (Druce, 1885), S. phlegon ruscia (Druce, 1895), S. tenuifascia (Hering, 1930) and S. tenuifascia daguana (Hering, 1930). Eucyanoides Toulgoët, 1988, currently a synonym of Thyrgis, is made a new subjective synonym of Seileria. Based on DNA barcodes, we recognise three very similar, sexually dimorphic and in two cases polymorphic South American species of Calodesma with some phenotypes in common but very similar male genitalia: C. militta (BOLD:AAK1660), C. sp. cf. collaris (BOLD:ABZ2392) and C. pseudocollaris Cock new species (BOLD:AEI2170). Calodesma militta is widespread in South America, with two male morphs (collaris and dioptis) and two female morphs with variable markings (white and orange morphs). Centronia plorator Kaye, [1923] and Thyrgis lacryma Dognin, 1919 are variants of the white female morph and are new synonyms of Calodesma militta. A third female morph with red markings was not sequenced and could not be allocated to a species. Calodesma sp. cf. collaris (BOLD:ABZ2392) occurs in southern South America with both male morphs but only a white female morph. Calodesma pseudocollaris new species (BOLD:AEI2170) is only known from Trinidad, with one male morph (collaris) and the white female morph. Although more than ten morphs relating to this complex have been described as species, they cannot be synonymised without more data on distribution of the different species or DNA barcodes from the type specimens. Collated life history information indicates species of this group are split between Malpighiaceae feeders and Bromeliaceae feeders, but more work is needed to define these differences. The morphism patterns observed are discussed in terms of Müllerian mimicry and mimicry rings, and we suggest that in Trinidad (and elsewhere) there is a loose mimicry ring of diurnal black species with white spots or transparent patches on the wings which are most conspicuous and frequently observed when feeding on white Asteraceae flowers.

More winners than losers over 12 years of monitoring tiger moths (Erebidae: Arctiinae) on Barro Colorado Island, Panama.

Understanding the causes and consequences of insect declines has become an important goal in ecology, particularly in the tropics, where most terrestrial diversity exists. Over the past 12 years, the ForestGEO Arthropod Initiative has systematically monitored multiple insect groups on Barro Colorado Island (BCI), Panama, providing baseline data for assessing long-term population trends. Here, we estimate the rates of change in abundance among 96 tiger moth species on BCI. Population trends of most species were stable (n = 20) or increasing (n = 62), with few (n = 14) declining species. Our analysis of morphological and climatic sensitivity traits associated with population trends shows that species-specific responses to climate were most strongly linked with trends. Specifically, tiger moth species that are more abundant in warmer and wetter years are more likely to show population increases. Our study contrasts with recent findings indicating insect decline in tropical and temperate regions. These results highlight the significant role of biotic responses to climate in determining long-term population trends and suggest that future climate changes are likely to impact tropical insect communities.

Taxonomic changes in the Neotropical wasp moths, Euchromiina and Ctenuchina (Lepidoptera, Erebidae, Arctiinae, Arctiini) relating to the fauna of Trinidad & Tobago, with descriptions of new species.

The following new species are described: Calonotos flemingi new species from Trinidad; Valvaminor jacerda new species from Trinidad and Venezuela. The following species are made subspecies new status: Calonotos tripunctata Druce, 1898 of C. aterrima (Sepp, 1847); Calonotos craneae Fleming, 1957 of Calonotos helymus (Cramer, 1775). The following subspecies is raised to species new status: Cosmosoma bolivarensis Klages, 1906 (formerly Cosmosoma achemon var. bolivarensis). The following are new combinations: Myrmecopsis kenedyae (Fleming, 1957) (Euchromiina) (formerly Pseudosphex kenedyae Ctenuchina); Valvaminor endoleuca (Druce, 1905) (formerly Mesothen endoleuca); Xanthyda beebei (Fleming, 1957) (formerly Pheia beebei); Eucerioides obliquifascia (Rothschild, 1912) (formerly Eucereon obliquifascia); Uranophora andrei (Rothschild, 1912) (formerly Ctenucha andrei). A lectotype is designated for Calonotos tiburtus trinidadensis Strand, 1915, which is a new synonym of Calonotos aterrima (Sepp, 1847). Aethria jacksoni Kaye 1925 is a new synonym of Aethria aner Hampson 1905.

Taxonomic changes in the Neotropical Arctiinae, Arctiini (Lepidoptera, Erebidae) relating to the fauna of Trinidad and Tobago.

In preparation for a general account of the Trinidad and Tobago Arctiini, the following taxonomic changes are made and justification provided. A lectotype is designated for Castrica sordidior Rothschild, 1909. Castrica oweni Schaus, 1896, stat rev. is returned to species rank. The following new synonyms are established: Castrica sordidior Rothschild, 1909 syn. nov. of Castrica oweni Schaus, 1896; Automolis nigroapicalis Gaede, 1923, Automolis semicostalis Rothschild, 1909, Automolis alboatra Rothschild, 1909, Automolis alboatra borussica Seitz, 1922, Sallaea unifascia Druce, 1899, Automolis hamifera Dognin, 1907, and Automolis apicata Schaus, 1905 syn. nov. of Pryteria costata Mschler, 1883; and Sphinx Adfeit. psamas Cramer, [1779] syn. nov. of Phalaena Noctua onytes Cramer, [1777]. Virbia birchi Druce, 1911 is confirmed to be a synonym of Phalaena medarda Stoll, [1781]. Pryteria tenuis (Rothschild, 1935) stat. nov. and P. intensa (Rothschild, 1935) stat. nov. are raised to species level pending clarification of the genus Pryteria in Central America.

Partial revision of the genus Robinsonia Grote 1866: description of five new species for the Neotropical fauna (Lepidoptera, Erebidae, Arctiinae, Phaegopterina).

The genus Robinsonia Grote, 1866 is partially reviewed following a large DNA barcode campaign. In the Robinsonia praphoea Dognin, 1906 group three new species are described: R. simulans sp. n. from French Guiana, up to now confused with R. praphoea itself and then R. decaensi sp. n. and R. maranhensis sp. n. both from the lower Amazon. R. drechseli sp. n. is described from Paraguay and R. inexpectata sp. n., a species close to R. mera (Schaus, 1910) from Costa Rica, is described as new from Peru and Bolivia. Finally the full species status is confirmed for R. flavicorpus Dognin, 1910 which is found to be differentiable from R. marginata Rothschild, 1909. All types are figured along with the male genitalia for most and some female genitalia for all studied species.

Pairing of two highly sexually dimorphic species within the genus Lophocampa Harris, 1841 (Lepidoptera: Erebidae: Arctiini).

Two Lophocampa species previously known only by females are paired with morphologically highly different male specimens. This pairing was initiated after the discovery of a mosaic gynandromorph specimen and then confirmed using the mitochondrial COI gene (the so-called DNA barcode). Following the discovery of a labeling error by Rothschild during the original description of two species, two recombinations are proposed. Pairs for each species are illustrated and the male specimens are described for the first time.

Gloora gen. nov. (Lepidoptera: Erebidae: Arctiinae: Arctiini: Ctenuchina) for several Agylla-like Arctiinae.

Gloora gen. nov. is established for Eucereon alba (Druce, 1894), Hyaleucerea mundula (Berg, 1882), Agaraea sericeum (Zerny, 1931), and Gloora canae sp. nov. These species are (re­)described considering male genitalia in particular and, in case, barcodes. Further species which might fit into Gloora gen. nov. are discussed.

A Central Small Amino Acid in the VAMP2 Transmembrane Domain Regulates the Fusion Pore in Exocytosis.

Exocytosis depends on cytosolic domains of SNARE proteins but the function of the transmembrane domains (TMDs) in membrane fusion remains controversial. The TMD of the SNARE protein synaptobrevin2/VAMP2 contains two highly conserved small amino acids, G100 and C103, in its central portion. Substituting G100 and/or C103 with the ß-branched amino acid valine impairs the structural flexibility of the TMD in terms of α-helix/ß-sheet transitions in model membranes (measured by infrared reflection-absorption or evanescent wave spectroscopy) during increase in protein/lipid ratios, a parameter expected to be altered by recruitment of SNAREs at fusion sites. This structural change is accompanied by reduced membrane fluidity (measured by infrared ellipsometry). The G100V/C103V mutation nearly abolishes depolarization-evoked exocytosis (measured by membrane capacitance) and hormone secretion (measured biochemically). Single-vesicle optical (by TIRF microscopy) and biophysical measurements of ATP release indicate that G100V/C103V retards initial fusion-pore opening, hinders its expansion and leads to premature closure in most instances. We conclude that the TMD of VAMP2 plays a critical role in membrane fusion and that the structural mobility provided by the central small amino acids is crucial for exocytosis by influencing the molecular re-arrangements of the lipid membrane that are necessary for fusion pore opening and expansion.

Fast Census of Moth Diversity in the Neotropics: A Comparison of Field-Assigned Morphospecies and DNA Barcoding in Tiger Moths.

The morphological species delimitations (i.e. morphospecies) have long been the best way to avoid the taxonomic impediment and compare insect taxa biodiversity in highly diverse tropical and subtropical regions. The development of DNA barcoding, however, has shown great potential to replace (or at least complement) the morphospecies approach, with the advantage of relying on automated methods implemented in computer programs or even online rather than in often subjective morphological features. We sampled moths extensively for two years using light traps in a patch of the highly endangered Atlantic Forest of Brazil to produce a nearly complete census of arctiines (Noctuoidea: Erebidae), whose species richness was compared using different morphological and molecular approaches (DNA barcoding). A total of 1,075 barcode sequences of 286 morphospecies were analyzed. Based on the clustering method Barcode Index Number (BIN) we found a taxonomic bias of approximately 30% in our initial morphological assessment. However, a morphological reassessment revealed that the correspondence between morphospecies and molecular operational taxonomic units (MOTUs) can be up to 94% if differences in genitalia morphology are evaluated in individuals of different MOTUs originated from the same morphospecies (putative cases of cryptic species), and by recording if individuals of different genders in different morphospecies merge together in the same MOTU (putative cases of sexual dimorphism). The results of two other clustering methods (i.e. Automatic Barcode Gap Discovery and 2% threshold) were very similar to those of the BIN approach. Using empirical data we have shown that DNA barcoding performed substantially better than the morphospecies approach, based on superficial morphology, to delimit species of a highly diverse moth taxon, and thus should be used in species inventories.

Monitoring the Interactions of a Ternary Complex Using NMR Spectroscopy: The Case of Sugars, Polyphenols, and Proteins.

Gaining insight into intermolecular interactions between multiple species is possible at an atomic level by looking at different parameters using different NMR techniques. In the specific case of the astringency sensation, in which at least three molecular species are involved, different NMR techniques combined with dynamic light scattering and molecular modeling contribute to decipher the role of each component in the interaction mode and to assess the thermodynamic parameters governing this complex interaction. The binding process between a saliva peptide, a polyphenol, and polysaccharides was monitored by following 1H chemical shift variations, changes in NMR peak areas, and size of the formed complex. These NMR experiments deliver a complete picture of the association pathway, assessed by dynamic light scattering and molecular dynamics simulations: all of the data collected converge toward a comprehensive mode of interaction in which sugars indirectly play a role in astringency by sequestering part of the polyphenols, reducing their effective concentration to bind saliva proteins.

Iterative design of a helically folded aromatic oligoamide sequence for the selective encapsulation of fructose.

The ab initio design of synthetic molecular receptors for a specific biomolecular guest remains an elusive objective, particularly for targets such as monosaccharides, which have very close structural analogues. Here we report a powerful approach to produce receptors with very high selectivity for specific monosaccharides and, as a demonstration, we develop a foldamer that selectively encapsulates fructose. The approach uses an iterative design process that exploits the modular structure of folded synthetic oligomer sequences in conjunction with molecular modelling and structural characterization to inform subsequent refinements. Starting from a first-principles design taking size, shape and hydrogen-bonding ability into account and using the high predictability of aromatic oligoamide foldamer conformations and their propensity to crystallize, a sequence that binds to ß-D-fructopyranose in organic solvents with atomic-scale complementarity was obtained in just a few iterative modifications. This scheme, which mimics the adaptable construction of biopolymers from a limited number of monomer units, provides a general protocol for the development of selective receptors.

Acute regulation of PDK1 by a complex interplay of molecular switches.

Phosphoinositide-dependent kinase 1 (PDK1) is the master regulator of at least 23 other AGC kinases whose downstream signalling has often been implicated in various diseases and in particular in cancer. Therefore there has been great interest in determining how PDK1 is controlled and how it regulates its substrates spatially and temporally. The understanding of these mechanisms could offer new possibilities for therapeutic intervention. Over the years, a more comprehensive view of the mechanisms involved in the regulation of PDK1 has emerged and these comprise serine/threonine as well as tyrosine phosphorylation, subcellular localization, regulator binding and conformation status. In the present review, we discuss how various molecular mechanisms are together responsible for the conformational regulation behind the activation of PDK1 in cells.

Design, synthesis and biological evaluation of Pontin ATPase inhibitors through a molecular docking approach.

A virtual screening strategy, through molecular docking, for the elaboration of an electronic library of Pontin inhibitors has resulted in the identification of two original scaffolds. The chemical synthesis of four candidates allowed extensive biological evaluations for their anticancer activity. Two compounds displayed an effect on Pontin ATPase activity, and one of them also exhibited a noticeable effect on cell growth. Further biological studies revealed that the most active compound induced apoptotic cell death together with necrosis, this latter effect being likely related to the cellular balance of ATP regulation.

Structure of a complex formed by a protein and a helical aromatic oligoamide foldamer at 2.1 Å resolution.

In the search of molecules that could recognize sizeable areas of protein surfaces, a series of ten helical aromatic oligoamide foldamers was synthesized on solid phase. The foldamers comprise three to five monomers carrying various proteinogenic side chains, and exist as racemic mixtures of interconverting right-handed and left-handed helices. Functionalization of the foldamers by a nanomolar ligand of human carbonic anhydrase II (HCA) ensured that they would be held in close proximity to the protein surface. Foldamer-protein interactions were screened by circular dichroism (CD). One foldamer displayed intense CD bands indicating that a preferred helix handedness is induced upon interacting with the protein surface. The crystal structure of the complex between this foldamer and HCA could be resolved at 2.1 Å resolution and revealed a number of unanticipated protein-foldamer, foldamer-foldamer, and protein-protein interactions.

Molecular dynamics analysis of a novel ß3 Pro189Ser mutation in a patient with glanzmann thrombasthenia differentially affecting αIIbß3 and αvß3 expression.

Mutations in ITGA2B and ITGB3 cause Glanzmann thrombasthenia, an inherited bleeding disorder in which platelets fail to aggregate when stimulated. Whereas an absence of expression or qualitative defects of αIIbß3 mainly affect platelets and megakaryocytes, αvß3 has a widespread tissue distribution. Little is known of how amino acid substitutions of ß3 comparatively affect the expression and structure of both integrins. We now report computer modelling including molecular dynamics simulations of extracellular head domains of αIIbß3 and αvß3 to determine the role of a novel ß3 Pro189Ser (P163S in the mature protein) substitution that abrogates αIIbß3 expression in platelets while allowing synthesis of αvß3. Transfection of wild-type and mutated integrins in CHO cells confirmed that only αvß3 surface expression was maintained. Modeling initially confirmed that replacement of αIIb by αv in the dimer results in a significant decrease in surface contacts at the subunit interface. For αIIbß3, the presence of ß3S163 specifically displaces an α-helix starting at position 259 and interacting with ß3R261 while there is a moderate 11% increase in intra-subunit H-bonds and a very weak decrease in the global H-bond network. In contrast, for αvß3, S163 has different effects with ß3R261 coming deeper into the propeller with a 43% increase in intra-subunit H-bonds but with little effect on the global H-bond network. Compared to the WT integrins, the P163S mutation induces a small increase in the inter-subunit fluctuations for αIIbß3 but a more rigid structure for αvß3. Overall, this mutation stabilizes αvß3 despite preventing αIIbß3 expression.

Four new Neotropical Lophocampa species with a redescription of Lophocampa atriceps (Hampson) (Lepidoptera, Erebidae, Arctiinae).

Four new species of Lophocampa Harris, are described and illustrated: Lophocampa flavodorsata sp. n., Lophocampa griseidorsata sp. n., Lophocampa herbini sp. n. and Lophocampa sullivani sp. n. Lophocampa atriceps (Hampson) is redescribed, illustrated and compared to the new species.

RésuméQuatre nouvelles espèces de Lophocampa Harris sont décrites et illustrées, Lophocampa flavodorsatasp. n., Lophocampa griseidorsatasp. n., Lophocampa herbinisp. n. et Lophocampa sullivanisp. n.Lophocampa atriceps Hampson, est redécrite illustrée, et compareé avec les especies nouvelles.

Helix-forming propensity of aliphatic urea oligomers incorporating noncanonical residue substitution patterns.

Aliphatic N,N'-linked oligoureas are peptidomimetic foldamers that adopt a well-defined helical secondary structure stabilized by a collection of remote three-center H-bonds closing 12- and 14-membered pseudorings. Delineating the rules that govern helix formation depending on the nature of constituent units is of practical utility if one aims to utilize this helical fold to place side chains in a given arrangement and elaborate functional helices. In this work, we tested whether the helix geometry is compatible with alternative substitution patterns. The central -NH-CH(R)-CH2-NH-CO- residue in a model oligourea pentamer sequence was replaced by guest units bearing various substitution patterns [e.g., -NH-CH2-CH2-NH-CO-, -NH-CH2-CH(R)-NH-CO-, and -NH-CH(R(1))-CH(R(2))-NH-CO-], levels of preorganization (cyclic vs acyclic residues), and stereochemistries, and the helix formation was systematically assessed. The extent of helix perturbation or stabilization was primarily monitored in solution by Fourier transform IR, NMR, and electronic circular dichroism spectroscopies. Our results indicate that although three new substitution patterns were accommodated in the 2.5-helix, the helical urea backbone in short oligomers is particularly sensitive to variations in the residue substitution pattern (position and stereochemistry). For example, the trans-1,2-diaminocyclohexane unit was experimentally found to break the helix nucleation, but the corresponding cis unit did not. Theoretical calculations helped to rationalize these results. The conformational preferences in this series of oligoureas were also studied at high resolution by X-ray structure analyses of a representative set of modified oligomers.

A novel small-molecule screening strategy identifies mitoxantrone as a RhoGTPase inhibitor.

RhoGTPases are GDP/GTP molecular switches that control a wide variety of cellular processes, thereby contributing to many diseases, including cancer. As a consequence, there is great interest in the identification of small-molecule inhibitors of RhoGTPases. In the present paper, using the property of GTP-loaded RhoGTPases to bind to their effectors, we describe a miniaturized and robust assay to monitor Rac1 GTPase activation that is suitable for large-scale high-throughput screening. A pilot compound library screen revealed that the topoisomerase II poison MTX (mitoxantrone) is an inhibitor of Rac1, and also inhibits RhoA and Cdc42 in vitro. We show that MTX prevents GTP binding to RhoA/Rac1/Cdc42 in vitro. Furthermore, MTX strongly inhibits RhoGTPase-mediated F-actin (filamentous actin) reorganization and cell migration. Hence, we report a novel biochemical assay yielding the identification of RhoGTPase inhibitors and we present a proof-of-concept validation with the identification of MTX as a novel pan-RhoGTPase inhibitor.

The colloidal state of tannins impacts the nature of their interaction with proteins: the case of salivary proline-rich protein/procyanidins binding.

While the definition of tannins has been historically associated with its propensity to bind proteins in a nonspecific way, it is now admitted that specific interaction also occurs. The case of the astringency perception is a good example to illustrate this phenomenon: astringency is commonly described as a tactile sensation induced by the precipitation of a complex composed of proline-rich proteins present in the human saliva and tannins present in beverages such as tea or red wines. In the present work, the interactions between a human saliva protein segment and three different procyanidins (B1, B3, and C2) were investigated at the atomic level by NMR and molecular dynamics. The data provided evidence for (i) an increase in affinity compared to shortest human saliva peptides, which is accounted for by protein "wraping around" the tannin, (ii) a specificity in the interaction below tannin critical micelle concentration (CMC) of ca. 10 mM, with an affinity scale such that C2 > B1 > B3, and (iii) a nonspecific binding above tannin CMC that conducts irremediably to the precipitation of the tannins/protein complex. Such physicochemical findings describe in accurate terms saliva protein-tannin interactions and provide support for a more subtle description by oenologists of wine astringency perception in the mouth.