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PubMed1991

Cloning of genomic and complementary DNA encoding insect pheromone binding proteins: evidence for microdiversity.

Genomic DNA from the silk moth Antheraea pernyi bearing the gene of a pheromone binding protein has been isolated from a partial genomic library using specific cDNA probes. The DNA spans 3.5 kilobases, contains three exons and two intervening sequences that interrupt the protein coding region of the gene. A DNA fragment of a second gene was isolated and the complete primary structure of a corresponding cDNA clone was unravelled. The expression of two different genes, giving rise to different pheromone binding proteins, implies a more specific function of these proteins than was hitherto assumed.

Amino Acid Sequence↗
PubMed1991

Purification of a stage-specific and sequence-specific DNA-binding protein for the arylphorin gene of Sarcophaga peregrina.

A protein that binds specifically to the nucleotide sequence ACCACAACA located at residues -247 to -255 upstream of the +1 site of the arylphorin gene of Sarcophaga peregrina was purified to homogeneity from fat body nuclei of third instar larvae. This DNA-binding protein consisted of two subunits with molecular masses of 40 kDa and 42 kDa, respectively. Accurate transcription initiation of a truncated arylphorin gene in a nuclear extract of NIH-Sape-4 cells, an embryonic cell line of Sarcophaga, was significantly enhanced in the presence of the purified DNA-binding protein.

Animals↗
PubMed1992

Isolation and nucleotide sequence of cecropin B cDNA clones from the silkworm, Bombyx mori.

Two cDNA clones encoding cecropin B, an antibacterial protein, were isolated from a fat body cDNA library of the silkworm, Bombyx mori. Amino acid sequences of these clones, deduced from nucleotide sequences, were identical, including signal peptide regions. However, the nucleotide sequences were different at 30 positions. Deduced amino acid sequences of Bombyx mori cecropin B showed higher homology with cecropins from Lepidoptera than with those from Diptera.

Amino Acid Sequence↗
PubMedDate not supplied

Ribonucleoparticle-independent import of proteins into mammalian microsomes involves a membrane protein which is sensitive to chemical alkylation.

Import of the small precursor protein preprocecropin A (ppcec A) into dog pancreas microsomes under post-translational conditions does not involve the ribonucleoparticles, signal recognition particle and ribosome, and their receptors on the microsomal surface, docking protein and ribosome receptor. In this study, we attempted to obtain direct evidence for the involvement of proteinaceous membrane components in this alternative import mechanism by utilizing various sulfhydryl-modifying reagents (N-ethylmaleimide (NEM), N-iodoacetylaminoethyl-5-naphthylamine-1- sulphonic acid (AEDANS) and iodoacetamide (IAA]. As a result of observing the inhibitory effect of 2 reagents (NEM and AEDANS) on the microsomes with respect to ppcec A-import, we concluded that there is at least one membrane protein with a cytoplasmically exposed sulfhydryl involved in ppcep A-import. This membrane protein(s) is (are) distinct from membrane proteins which are known to be involved in protein import, such as the signal peptidase and the so-called signal sequence receptor.

Alkylating Agents↗
PubMed1995

Locustamyoinhibin-like (Lom-MIH) immunoreactivity in the head ganglia of the insects Neobellieria bullata, Mamestra brassicae, Leptinotarsa decemlineata and Leucophaea maderae.

A polyclonal antibody raised against locustamyoinhibin (Lom-MIH), a myoinhibiting neuropeptide of the locust Locusta migratoria, was used to search for locustamyoinhibin-like immunoreactivity in the central nervous system of the gray fleshfly, Neobellieria bullata, the Colorado potato beetle, Leptinotarsa decemlineata, the cabbage moth, Mamestra brassicae and the cockroach, Leucophaea maderae. In L. maderea, immunoreactive cells are present in the pars intercerebralis (PI), in nerve fibers leading to the corpus cardiacum (CC) and in the CC themselves. In N. bullata, three groups of cells are positive: one in the PI, one in the pars lateralis and one in the suboesophageal ganglion. In M. brassicae, there are only positive cells in the PI. No immunoreactivity was found in L. decemlineata. These results indicate that the presence of Lom-MIH immuno-like molecules is not restricted to the orthopterans, and that they can be localized in different parts of the head ganglia.

Amino Acid Sequence↗
PubMed1986

Antibacterial hemolymph proteins of Manduca sexta.

Exclusion column fractionated immune hemolymph of the M. sexta larva contains five peaks of anti-E. coli activity with molecular weights of greater than 140 kD and approximately 91, 54, 14 and 4 kD, plus one peak of lysozyme activity with a molecular weight of 17 kD. Purification of the 54 kD peak showed that this peak consists of the previously described M18 proteins which have monomeric weights of approximately 20 kD and had antibacterial activity against certain gram negative bacteria. Approximately 80% of the total hemolymph antibacterial activity was detected in the 14 and 4 kD peaks. These proteins, which kill both gram negative and gram positive bacteria, appeared to be directly analogous to the cecropins of H. cecropia. The greater than 140 and 91 kD peaks constituted only a minor part of the total antibacterial activity.

Animals↗
PubMed1990

Balbiani ring 3 in Chironomus tentans encodes a 185-kDa secretory protein which is synthesized throughout the fourth larval instar.

We have continued to map and identify genes encoding a family of secretory proteins. These proteins are synthesized in larval salivary glands of the midge, Chironomus tentans, and assemble in vivo into insoluble silk-like threads. The genes for several secretory proteins exist in Balbiani rings (BRs) on salivary-gland polytene chromosomes. A randomly primed cDNA clone, designated pCt185, hybridized in situ to BR3 and was shown on Northern blots to originate from a salivary gland-specific 6-kb poly(A) + RNA. The partial cDNA sequence contained 483 nucleotides including one open reading frame (ORF) encoding 160 amino acids (aa). A striking feature of the ORF was the periodic distribution of cysteine residues (Cys-X-Cys-X-Cys-X6-Cys) which occurred approximately every 22 aa. A cDNA-encoded 18-aa sequence was selected for chemical peptide synthesis. When affinity-purified antipeptide antibodies were incubated with a Western blot containing salivary-gland proteins they reacted specifically with a 185-kDa secretory protein (sp185). Developmental studies showed that sp185 and its mRNA were present in salivary glands throughout the fourth larval instar. Thus sp185 and a family of 1000-kDa secretory proteins are encoded by a class of genes that are expressed throughout the fourth instar. This contrasts with the developmentally regulated expression of the sp140 and sp195 genes whose expression is maximal during the prepupal stages of larval development.

Amino Acid Sequence↗
PubMed1995

Structure of two cecropin B-encoding genes and bacteria-inducible DNA-binding proteins which bind to the 5'-upstream regulatory region in the silkworm, Bombyx mori.

Two genomic DNAs encoding cecropin B (CecB), an antibacterial protein from Bombyx mori, were cloned and sequenced. The number of CecB genes was estimated to be more than four copies per haploid by genomic Southern blotting. Two genes, CecB1 and CecB2, were located tandemly within 12 kb in the same orientation. These two genes encoded identical amino acids, though 15 nucleotides (nt) were different in the coding region and the intron size varied. About 90% of the nt spanning 800 bp in the 5'-untranslated region (UTR) were identical between the two genes. This 5'-flanking region contained characteristic sequences such as a repetitive element of B. mori (Bm1), an interleukin-6 response element (IL-6 RE), and two putative lipopolysaccharide (LPS) response elements (LPS RE). An electrophoretic mobility shift assay (EMSA) showed that the fat body contains at least three different nuclear proteins inducible by bacteria which bind to the 5'-UTR, suggesting that these proteins may be involved in CecB expression triggered by bacteria.

Amino Acid Sequence↗
PubMed1996

Trichoplusia ni attacin A, a differentially displayed insect gene coding for an antibacterial protein.

The mRNA differential display method was used to isolate antibacterial defense genes from Trichoplusia ni. The mRNA population in last-instar T. ni larvae injected with bacteria was compared to that of untreated larvae. Using a PCR amplified probe corresponding to an induced mRNA, we were able to clone an attacin homolog from a lambda cDNA library from vaccinated larvae. The corresponding protein showed 63% identity to Hyalophora cecropia acidic attacin. The induction kinetics of T. ni attacin A gave optimal mRNA levels at 20 h post-infection. Genomic analysis showed this to be a single-copy gene with two introns.

Amino Acid Sequence↗
PubMed1995

Extraction of the synthetic lytic peptide, cecropin B, from biological fluid and analysis using reversed-phase high-performance liquid chromatography.

The lytic peptide cecropin B, originally isolated from the giant silk moth Hyalophora cecropia, has been found to possess antibacterial and cell lysis properties in vitro and some anticancer activity in vivo. An HPLC method was developed to study synthetic cecropin B concentrations in biological fluids. Cecropin B was recovered from culture medium by solid-phase extraction (40.0 +/- 2.4%), whereas in plasma it was highly protein-bound. The peptide was dissociated from proteins by citric acid and recovered by ultrafiltration (64.6 +/- 5.9%) and was unstable in plasma (half-life, 0.57 +/- 0.11 h). These analytical methods will facilitate future in vivo pharmacokinetic studies.

Amino Acid Sequence↗
PubMed1992

Isolation, primary structure and synthesis of neomyosuppressin, a myoinhibiting neuropeptide from the grey fleshfly, Neobellieria bullata.

1. An amidated decapeptide, showing strong inhibitory activity of spontaneous visceral muscle movement was isolated, from head extracts of 42 thousand fleshflies, Neobellieria bullata (Diptera, Sarcophagidae). 2. Amino acid sequencing and verification by peptide synthesis revealed the following primary structure: Thr-Asp-Val-Asp-His-Val-Phe-Leu-Arg-PheNH2. 3. The novel peptide was termed neomyosuppressin or Neb-MS. 4. During the process of consecutive high performance liquid chromatography (HPLC) purifications the biological activity of the samples was monitored using heterologous bioassay system. 5. The threshold level of synthetic Neb-MS was found to be 8.6 +/- 0.5 x 10(-11) M on the Leucophaea hindgut and 3.4 +/- 0.5 x 10(-10) M on the Locusta oviduct bioassay, respectively.

Amino Acid Sequence↗
PubMed1989

Molecular characterization of the Drosophila trp locus: a putative integral membrane protein required for phototransduction.

Recent studies suggest that the fly uses the inositol lipid signaling system for visual excitation and that the Drosophila transient receptor potential (trp) mutation disrupts this process subsequent to the production of IP3. In this paper, we show that trp encodes a novel 1275 amino acid protein with eight putative transmembrane segments. Immunolocalization indicates that the trp protein is expressed predominantly in the rhabdomeric membranes of the photoreceptor cells.

Amino Acid Sequence↗
PubMed1989

Proper function of the Drosophila trp gene product during pupal development is important for normal visual transduction in the adult.

The response of invertebrate photoreceptors consists of the summation of quantum bumps, each representing the response to a single photon. The bumps adapt depending on the intensity of the stimulus: their average size is relatively large in dim light and small in bright light. The rate of occurrence of the bumps varies proportionally with light intensity. In the Drosophila mutant trp, unlike in the wild type, the rate does not increase with increasing light intensity and the bumps do not adapt. Here we report an analysis of the trp gene and its expression in normal and mutant flies. Our results suggest that the trp protein is a novel photoreceptor membrane-associated protein, that this protein is not required for the occurrence of bumps but is necessary for adaptation, and that proper function of the trp gene product during pupal development is important for normal visual transduction in the adult.

Amino Acid Sequence↗
PubMed1995

Dmcdc2 kinase is required for both meiotic divisions during Drosophila spermatogenesis and is activated by the Twine/cdc25 phosphatase.

We have analyzed the requirement for Drosophila cdc2 kinase during spermatogenesis after generating temperature-sensitive mutant lines (Dmcdc2ts) by re-constructing mutations known to result in temperature sensitivity in fission yeast cdc2+. While meiotic spindles and metaphase plates were never formed in Dmcdc2ts mutants at high temperature, chromosomes still condensed in late spermatocytes and spermatid differentiation (sperm head and tail formation) continued. The same phenotype was also observed in twine and twine, Dmcdc2ts double mutant testes, consistent with the idea that the cdc2 kinase activity required for meiotic divisions is activated by the Twine/cdc25 phosphatase. Confirming this notion, we find that ectopic expression of the String/cdc25 phosphatase, which is known to activate the cdc2 kinase before mitosis, results in a partial rescue of meiotic divisions in twine mutant testis.

Amino Acid Sequence↗
PubMed1996

Expression patterns of developmental genes reveal segment and parasegment organization of D. melanogaster genital discs.

We have used the expression patterns of genes known to be important during early Drosophila development to determine the segment-parasegment organization of the genital discs and to localize the three primordia in the male and female genital discs, engrailed (en) and hedgehog (hh) were used to locate posterior compartments in A8-A10, while cubitus interrupts (ci) localized the anterior compartments for each segment, decapentaplegic (dpp) identified the anterior cells that abut en and hh at the anterior-posterior border. abdominal-A (abd-A) identified the anterior compartment for abdominal segment 8 (aA8) in females but was not detected in the repressed female primordium in male discs. Abdominal-B (Abd-B) was expressed throughout the discs except for a small area along the edge of the posterior lobes, leaving open the possibility that A11 may contribute to the genital discs, caudal (cad) was expressed segmentally in the anal primordium of A10, extending through the Abd-B unstained region, wingless (wg) and gooseberry (gsb) may have assumed an added role in the discs perhaps providing proximal-distal cues. Models are presented to show how the segments and parasegments may fuse together during embryogenesis to form the mature male and female genital discs.

Animals↗
PubMed1993

Expression and characterization of cDNAs for cecropin B, an antibacterial protein of the silkworm, Bombyx mori.

To analyze the induction mechanism of antibacterial protein gene expression, cDNAs coding for cecropin B have been cloned from the B. mori fat body cDNA library. Nucleotide sequences of two positive clones were determined and their amino acid sequences deduced. They revealed that these clones coded for the same cecropin, which is identical to purified cecropin B. However, the cDNAs contained different nucleotides at the third codon position and 5' or 3' non-coding regions. Results obtained by Northern blot analysis showed that the gene expression of B. mori cecropin B was rapidly induced by Escherichia coli and reached maximum levels 8 h after immunization. The expression of cecropin B gene occurred specifically in tissues, mainly in the fat body and hemocytes.

Amino Acid Sequence↗