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Insect Proteins (insect + protein)
Selected AbstractsConstruction of a cDNA library of Bemisia tabaci for use in the ,yeast two-hybrid screen' methodEPPO BULLETIN, Issue 1 2002S. Ohnesorge The molecular mechanisms involved in the circulative, non-propagative transmission pathway of TYLCV through its vector the whitefly Bemisia tabaci have hardly been studied. Points requiring investigation include the specific adhesion of virus coat protein to insect structures, the proteins involved in membrane passage in the insect and the possibility of replication of the virus in the vector. To isolate the insect proteins which are involved in transmission by interaction with viral proteins, we propose to use the ,yeast two-hybrid screen' genetic method. For this method, it is indispensable to have a ,cDNA library' of the organism concerned, cloned in plasmids, and our first step has been to develop this. A new method was developed for isolating whitefly mRNA. From this mRNA, cDNA was synthesized, ligated in the plasmid pGADT7 (Clontech) and transformed in bacteria to amplify the plasmid DNA. The number of independent clones and average insert size of the plasmids were determined. [source] Cloning and molecular characterization of two invertebrate-type lysozymes from Anopheles gambiaeINSECT MOLECULAR BIOLOGY, Issue 3 2008S. M. Paskewitz Abstract We sequenced and characterized two novel invertebrate-type lysozymes from the mosquito Anopheles gambiae. Alignment and phylogenetic analysis of these and a number of related insect proteins identified through bioinformatics strategies showed a high degree of conservation of this protein family throughout the Class Insecta. Expression profiles were examined for the two mosquito genes through semiquantitative and real-time PCR analysis. Lys i-1 transcripts were found in adult females in the fat body and Malpighian tubules, whereas Lys i-2 was detected only in fat bodies. Blood-feeding resulted in significantly increased transcript abundance for both genes in the midguts. Neither gene was upregulated following bacterial challenge. [source] Molecular characterization of a novel patched-related protein in Apis mellifera and Drosophila melanogasterARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 3 2008Luis Pastenes Abstract The molecular identification and characterization of the patched-related (ptr) gene and protein in Apis mellifera and Drosophila melanogaster are reported. Ptr proteins are closely related in predicted topology and domain organization to the protein encoded by the Drosophila segment polarity gene patched. Ptrs have 12 potential transmembrane domains arranged in two sets of 1+5 membrane-spanning segments containing a conserved sterol-sensing domain (SSD) and functional GxxxD and PPXY motifs. Phylogenetic analysis showed that Ptrs belong to a previously uncharacterized class of insect proteins that share a high level of sequence identity. Analysis using quantitative real-time polymerase chain reaction (qPCR) indicates that ptr gene is preferentially expressed during embryo stages of A. mellifera development; interestingly, this pattern of temporal expression was also observed for the D. melanogaster homologue, suggesting that these proteins might be involved in embryo morphogenesis. To understand Ptr function at the molecular level, we investigated the subcellular distribution of DmPtr. We have shown by biochemical analysis that DmPtr protein is tightly associated with membranes. Consistently, Ptr immunoreactivity appears to be localized at the sites of membrane furrow formation during cellularization of D. melanogaster embryos. These studies indicated that Ptrs belong to a previously uncharacterized class of insect transmembrane proteins that share a high level of sequence identity. Our analysis of ptr gene expression and protein localization suggest that Ptr might fulfil a developmental role by participating in processes that require growth and stabilization of plasma membrane. Arch. Insect Biochem. Physiol. 68:156,170, 2008. © 2008 Wiley-Liss, Inc. [source] Bracovirus gene products are highly divergent from insect proteinsARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 4 2008Annie Bézier Abstract Recently, several polydnavirus (PDV) genomes have been completely sequenced. The dsDNA circles enclosed in virus particles and injected by wasps into caterpillars appear to mainly encode virulence factors potentially involved in altering host immunity and/or development, thereby allowing the survival of the parasitoid larvae within the host tissues. Parasitoid wasps generally inject virulence factors produced in the venom gland. As PDV genomes are inherited vertically by wasps through a proviral form, wasp virulence genes may have been transferred to this chromosomal form, leading to their incorporation into virus particles. Indeed, many gene products from Cotesia congregata bracovirus (CcBV), such as PTPs, I,B-like, and cystatins, contain protein domains conserved in metazoans. Surprisingly however, CcBV virulence gene products are not more closely related to insect proteins than to human proteins. To determine whether the distance between CcBV and insect proteins is a specific feature of BV proteins or simply reflects a general high divergence of parasitoid wasp products, which might be due to parasitic lifestyle, we have analyzed the sequences of wasp genes obtained from a cDNA library. Wasp sequences having a high similarity with Apis mellifera genes involved in a variety of biological functions could be identified indicating that the high level of divergence observed for BV products is a hallmark of these viral proteins. We discuss how this divergence might be explained in the context of the current hypotheses on the origin and evolution of wasp-bracovirus associations. Arch. Insect Biochem. Physiol. 67:172,187, 2008. © 2008 Wiley-Liss, Inc. [source] | ||||||||||