Identification and localisation of the products of a putative eggshell precursor gene in the vitellarium of Schistosoma mansoni

Köster, Bärbel; Dargatz, Harald; Schröder, Johannes; Hirzmann, Jörg; Haarmann, Cäcilia; Symmons, Peter; Kunz, Werner

doi:10.1016/0166-6851(88)90169-7

Cited by 69 publications

(27 citation statements)

References 43 publications

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“…Three clones were identified that shared 100% sequence identity with S. mansoni eggshell proteins. p97D2 encoded the EGG2 ORF (5,16), and both p25G7 and p43F7 encoded the ORF of EGG3 (25). Sex-specific gene products, notably those involved in reproduction, are attractive targets for antihelminth intervention strategies (3) actin I protein (Met-121 to Asp-189) gained a positive C and S score in the SignalP-NN program.…”

Section: Resultsmentioning

confidence: 99%

“…Total RNAs from adult worms, eggs and cercariae were extracted by using Trizol reagent in accordance with the manufacturer's instructions. Single-stranded cDNA was generated by priming 1 to 3 g of total RNA with 500 ng of oligo(dT) [12][13][14][15][16][17][18] random primers (Boehringer Mannheim) with Superscript II reverse transcriptase (RT) (Life Technologies). Control reactions (without the addition of RT) were included to monitor for contamination with genomic DNA.…”

Section: Methodsmentioning

confidence: 99%

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Isolation of cDNAs Encoding Secreted and Transmembrane Proteins fromSchistosoma mansoniby a Signal Sequence Trap Method

et al. 2003

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Surface and secreted proteins of schistosomes orchestrate the basic physiologic requirements of a parasitic existence. These proteins are often exposed to host tissues during penetration, migration, feeding, and immune evasion, and they are obvious targets for control strategies. Signal sequence trap (SST) represents a novel approach that selects for cDNAs encoding secreted and surface proteins with N-terminal signal peptides, so we constructed a randomly primed adult Schistosoma mansoni cDNA library fused to a signalless reporter gene encoding placental alkaline phosphatase. The library was used to transfect COS-7 cells, which were then assayed for the presence of reporter at the cell surface. Eighteen S. mansoni cDNA fragments were isolated and sequenced. Expression profiles of the novel clones were determined for different developmental stages; some transcripts were restricted to single-sex adult worms, while others were ubiquitously distributed. Most clones contained signal peptides or signal anchors as determined by the SignalP algorithm. Open reading frames (ORFs) were categorized as follows: (i) previously identified S. mansoni cDNAs encoding proteins of known function; (ii) cDNAs encoding proteins of known function in other organisms but novel for Schistosoma; (iii) S. mansoni expressed sequence tags (ESTs) of unknown function; and (iv) completely novel ORFs without homologues (including ESTs) from any phylum. Clones of particular interest included tetraspanins similar to human cell surface antigens, a protein kinase, and ORFs transcribed in the antisense orientation to previously characterized S. mansoni cDNAs. This is the first report describing the use of SST as a tool for identifying secreted proteins from any pathogenic organism.

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Isolation of cDNAs Encoding Secreted and Transmembrane Proteins fromSchistosoma mansoniby a Signal Sequence Trap Method

et al. 2003

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“…A S. rnansnni stock from Liberia was cultured as described previously (Koster et al, 1988) except that Syrian hamsters were used as mammalian hosts.…”

Section: Methodsmentioning

confidence: 99%

“…To control the integrity of the proteins, the extracts were treated with SDS to a final concentration of 2 % and separated on 7.5 % SDSPAGE as previously described (Koster et al, 1988). To ensure that nucleases have not destroyed the RNA probes, agarose/ formaldehyde gel electrophoresis was performed (SchiiBler et al, 1995a).…”

Section: Gel Retardation Assay Protein Extracts Of Schistosomes Andmentioning

confidence: 99%

Ferritin mRNAs in Schistosoma Mansoni do not have Iron‐Responsive Elements for Post‐Transcriptional Regulation

Schüssler

Pötters

Winnen

et al. 1996

European Journal of Biochemistry

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Schistosomu mansoni possesses two isoforms of ferritin, soma and yolk ferritin. The soma ferritin occurs at a low level in most cells of both genders, whereas the yolk ferritin is a female-specific gene product that is expressed at high level in the vitellarium. In higher animals, ferritin mRNA is regulated by iron via the interaction of cytoplasmic binding proteins (IRPs) with a specific sequence element in the 5' untranslated region (UTR) referred to as the iron-responsive element (IRE). Sequence studies of the 5' UTRs, gel retardation assays, and hybridization experiments show that neither ferritin mRNAs of S. rnansoni is regulated by an IRE/IRP mechanism. It is suggested that ferritins in schistosomes are controlled only at the transcriptional level.

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“…This indicated a putative antisense regulation of this gene, a phenomenon well known for eukaryotes including schistosomes (Verjovski-Almeida et al 2007). Therefore, as positive and negative controls we included in situ hybridizations with antisense and sense probes of p14 (Kunz et al 1987), which represents a high abundantly transcribed gene coding for an eggshell precursor protein shown before to be expressed in the vitellarium (Köster et al 1988). To confirm the specificity of the SmcGK1 antisense signals, strand-specific RT-PCRs were performed using RNAs of ef, uf, em and um as template (Fig.…”

Section: Cdna Sequence Of Smcgk1mentioning

confidence: 99%

Characterization of the cGMP-dependent protein kinase SmcGK1 of Schistosoma mansoni

Leutner

Beckmann

Grevelding

2011

An. Acad. Bras. Ciênc.

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Schistosomes are trematode parasites and of worldwide medical importance for humans and animals. Growth and development of these parasites require a specific host environment, but also permanent communication processes between the two genders. Accumulating molecular evidence indicates that the responsible interactions are mediated by signal transduction processes. Conserved signaling molecules were identified, and first approaches made for their characterization. However, no representative of the conserved family of cGMP-dependent protein kinases (cGKs) has been described in this parasite yet. Within the Schistosoma mansoni genome data-set we identified cGK homologs, of which one was investigated in more detail in this study. We present the cloning of SmcGK1, whose sequence shows homology to cGKs of higher eukaryotes. SmcGK1 was found to be gender-independently transcribed in adult schistosomes. The occurrence of SmcGK1 sense and antisense transcripts suggests that the expression of this gene is controlled at the post-transcriptional level. In situ hybridization experiments demonstrated a gonad-preferential expression profile in both genders indicating a role of SmcGK1, at least during sexual development of schistosomes. Using a cGK-specific inhibitor to treat adult schistosomes in vitro finally resulted in a multifaceted phenotype including slow motion, oocyte congestion, and reduced egg production.

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Identification and localisation of the products of a putative eggshell precursor gene in the vitellarium of Schistosoma mansoni

Cited by 69 publications

References 43 publications

Isolation of cDNAs Encoding Secreted and Transmembrane Proteins fromSchistosoma mansoniby a Signal Sequence Trap Method

Isolation of cDNAs Encoding Secreted and Transmembrane Proteins fromSchistosoma mansoniby a Signal Sequence Trap Method

Ferritin mRNAs in Schistosoma Mansoni do not have Iron‐Responsive Elements for Post‐Transcriptional Regulation

Characterization of the cGMP-dependent protein kinase SmcGK1 of Schistosoma mansoni

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