Angiogenin-catalyzed cleavage within tRNA anticodon-loops identified by cP-RNA-seq.

Angiogenin (Ang), an endoribonuclease belonging to the RNase A superfamily, cleaves the anticodon-loops of tRNAs to produce tRNA half molecules. Although previous studies have demonstrated the involvement of Ang in the pathobiology of neurodegenerative disorders, the characterization of Ang-generated tRNA halves in neuronal cells remains limited. This is partly due to the technical limitations of standard RNA-seq methods, which cannot capture Ang-generated RNAs containing a 2',3'-cyclic phosphate (cP).

Heterochromatin-dependent transcription links the PRC2 complex to small RNA-mediated DNA elimination.

Facultative heterochromatin is marked by the repressive histone modification H3K27me3 in eukaryotes. Deposited by the PRC2 complex, H3K27me3 is essential for regulating gene expression during development, and chromatin bearing this mark is generally considered transcriptionally inert. The PRC2 complex has also been linked to programmed DNA elimination during development in ciliates such as Paramecium.

tRNA methylation resolves codon usage bias at the limit of cell viability.

Codon usage of each genome is closely correlated with the abundance of tRNA isoacceptors. How codon usage bias is resolved by tRNA post-transcriptional modifications is largely unknown. Here we demonstrate that the N-methylation of guanosine at position 37 (mG37) on the 3'-side of the anticodon, while not directly responsible for reading of codons, is a neutralizer that resolves differential decoding of proline codons.

RNase κ promotes robust piRNA production by generating 2',3'-cyclic phosphate-containing precursors.

In animal germlines, PIWI proteins and the associated PIWI-interacting RNAs (piRNAs) protect genome integrity by silencing transposons. Here we report the extensive sequence and quantitative correlations between 2',3'-cyclic phosphate-containing RNAs (cP-RNAs), identified using cP-RNA-seq, and piRNAs in the Bombyx germ cell line and mouse testes. The cP-RNAs containing 5'-phosphate (P-cP-RNAs) identified by P-cP-RNA-seq harbor highly consistent 5'-end positions as the piRNAs and are loaded onto PIWI protein, suggesting their direct utilization as piRNA precursors.

tRNA Methylation Is a Global Determinant of Bacterial Multi-drug Resistance.

Gram-negative bacteria are intrinsically resistant to drugs because of their double-membrane envelope structure that acts as a permeability barrier and as an anchor for efflux pumps. Antibiotics are blocked and expelled from cells and cannot reach high-enough intracellular concentrations to exert a therapeutic effect. Efforts to target one membrane protein at a time have been ineffective.

Selective terminal methylation of a tRNA wobble base.

Active tRNAs are extensively post-transcriptionally modified, particularly at the wobble position 34 and the position 37 on the 3'-side of the anticodon. The 5-carboxy-methoxy modification of U34 (cmo5U34) is present in Gram-negative tRNAs for six amino acids (Ala, Ser, Pro, Thr, Leu and Val), four of which (Ala, Ser, Pro and Thr) have a terminal methyl group to form 5-methoxy-carbonyl-methoxy-uridine (mcmo5U34) for higher reading-frame accuracy. The molecular basis for the selective terminal methylation is not understood.

TrmD: A Methyl Transferase for tRNA Methylation With mG37.

TrmD is an S-adenosyl methionine (AdoMet)-dependent methyl transferase that synthesizes the methylated mG37 in tRNA. TrmD is specific to and essential for bacterial growth, and it is fundamentally distinct from its eukaryotic and archaeal counterpart Trm5. TrmD is unusual by using a topological protein knot to bind AdoMet.

Detection and molecular status of Isospora sp. from the domestic pigeon (Columba livia domestica).

The domestic pigeon, Columba livia domestica, is reared for meat production, as a pet, or for racing. Few reports have characterized the parasitic protists from the genus Isospora isolated from Columbiformes. We detected Isospora-like oocysts from C.

Plant hormone cytokinins control cell cycle progression and plastid replication in apicomplexan parasites.

Cytokinins are plant hormones that are involved in regulation of cell proliferation, cell cycle progression, and cell and plastid development. Here, we show that the apicomplexan parasites Toxoplasma gondii and Plasmodium berghei, an opportunistic human pathogen and a rodent malaria agent, respectively, produce cytokinins via a biosynthetic pathway similar to that in plants. Cytokinins regulate the growth and cell cycle progression of T.

A host cell membrane microdomain is a critical factor for organelle discharge by Toxoplasma gondii.

Host cell microdomains are involved in the attachment, entry, and replication of intracellular microbial pathogens. Entry into the host cell of Toxoplasma gondii and the subsequent survival of this protozoan parasite are tightly coupled with the proteins secreted from organelle called rhoptry. The rhoptry proteins are rapidly discharged into clusters of vesicles, called evacuoles, which are then delivered to parasitophorous vacuoles (PVs) or nucleus.

In vitro and in vivo effects of the phytohormone inhibitor fluridone against Neospora caninum infection.

Neospora caninum causes abortion and stillbirth in cattle. Identification of effective drugs against this parasite remains a challenge. Previous studies have suggested that disruption of abscisic acid (ABA)-mediated signaling in apicomplexan parasites such as Toxoplasma gondii offers a new drug target.

Plant Hormone Salicylic Acid Produced by a Malaria Parasite Controls Host Immunity and Cerebral Malaria Outcome.

The apicomplexan parasite Toxoplasma gondii produces the plant hormone abscisic acid, but it is unclear if phytohormones are produced by the malaria parasite Plasmodium spp., the most important parasite of this phylum. Here, we report detection of salicylic acid, an immune-related phytohormone of land plants, in P.

Detection and genotyping of Cryptosporidium spp. in large Japanese field mice, Apodemus speciosus.

The genus Cryptosporidium, which is an obligate intracellular parasite, infects various vertebrates and causes a diarrheal disease known as cryptosporidiosis. Wild rodents are naturally infected with zoonotic Cryptosporidium; thus, they are potential reservoirs of the parasites. Mice are common rodents frequently found in agricultural areas and have many opportunities to contact other wild animals, livestock, and humans.

Molecular characterization of Cryptosporidium spp. in grazing beef cattle in Japan.

Cattle are major hosts of Cryptosporidium spp. Cryptosporidiosis in neonatal calves is associated with retarded growth, weight loss and calf mortality, and zoonotic infections in humans. In many areas, cow-calf glazing system is an important beef cattle rearing method with distinct advantages in terms of cost and the labor required.

Molecular analysis of Cryptosporidium parvum HNJ-1 isolated in Japan.

Cryptosporidium parvum HNJ-1 is widely used as a reference strain in Japan. In the present study, the parasite was subjected for further molecular analysis including transcribed ribosomal region (ITS rRNA), dihydrofolate reductase (DHFR) and surface glycoprotein (GP60) genes. Partial sequence analysis of these genes indicated extensive polymorphism in ITS region compared with relevant sequences of other Cryptosporidium parvum isolates.