Organism | UniProt | Comment | Textmining |
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Plasmodium falciparum | - |
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Synonyms | Comment | Organism |
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PfRNase II | - |
Plasmodium falciparum |
RNase II | - |
Plasmodium falciparum |
General Information | Comment | Organism |
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malfunction | a specific subclass of var genes called upsA are strongly up-regulated in parasites that expressed a defective PfRNase II (C-terminally tagged with the FKBP destabilization domain) compared to wild-type parasites. Different combinations of up to 3 distinct upsA var genes, together with an upsC var gene, were upregulated simultaneously in single parasite clones | Plasmodium falciparum |
metabolism | exoribonuclease-mediated gene silencing, mechanism and a more general regulatory role of ribonucleases in dynamic gene expression in Plasmodium falciparum, overview | Plasmodium falciparum |
additional information | RNase II of Plasmodium falciparum is a non-canonical exoribonuclease that contains a putative RNase II domain (termed PfRNase II). Loss of PfRNase II affects the strict gene counting mechanism that controls monoallelic var gene expression | Plasmodium falciparum |
physiological function | although genes represent monocistronic units that are expressed in a life cycle stage-specific manner, posttranscriptional regulation via translational repression of mRNA has been observed in parasite stages that transition from the vertebrate host to the Anopheles vector. In Plasmodium falciparum stages that infect human erythrocytes, a subgroup of genes that have been thought to be transcriptionally silent are actually transcribed but degraded immediately by an RNase II that is recruited to these gene loci. This cryptic RNA is not detectable in steady-state RNA but has been detected using nuclear run-on techniques and in mutant RNase II parasites. Nascent RNA degradation controls virulence genes expressed in a monoallelic fashion and noncoding RNAs (ncRNAs), but also a number of housekeeping-like of genes. PfRNase II is recruited to certain gene loci and accelerates the decay of mRNAs and ncRNA. PfRNase II is highly enriched at the promoters and introns of silenced upsA gene loci, and transcription analysis revealed that any nascent transcripts from these genes are only short-lived, cryptic mRNAs. Exoribonuclease-mediated gene silencing, mechanism, overview | Plasmodium falciparum |