Disease relevance of Tetrahymena

• The Tetrahymena rRNA intron self-splices in E. coli: in vivo evidence for the importance of key base-paired regions of RNA for RNA enzyme function [1].
• Site-directed mutagenesis and kinetic analysis of RNA splicing were used to identify a base triple in the conserved core of both a cyanobacterial (Anabaena) and a eukaryotic (Tetrahymena) group I intron [2].
• To date, four RNA folds have been determined at near-atomic resolution by X-ray crystallography: transfer RNA, the hammerhead ribozyme, the P4-P6 domain of the Tetrahymena group I intron, and the hepatitis delta virus ribozyme [3].
• The Tetrahymena self-splicing rRNA intron further has sequences homologous with regions of potato spindle tuber viroid associated with the severity of viroid symptoms [4].
• We have studied a synthetic model of the P4-P6 triple-helical domain in the bacteriophage T4 nrdB group I intron, which has a core sequence analogous to the Tetrahymena ribozyme [5].

High impact information on Tetrahymena

• Methylation of histone h3 at lysine 9 targets programmed DNA elimination in tetrahymena [6].
• Phosphorylation of histone H3 at serine 10 occurs during mitosis and meiosis in a wide range of eukaryotes and has been shown to be required for proper chromosome transmission in Tetrahymena [7].
• We have cloned and characterized the rat telomerase protein component 1 gene (TLP1), which is related to the gene for Tetrahymena p80 [8].
• This Tetrahymena enzyme is strikingly homologous to the yeast protein Gcn5, a putative transcriptional adaptor, and we demonstrate that recombinant Gcn5p possesses HAT activity [9].
• In a linker histone H1 knockout strain (delta H1) of Tetrahymena thermophila, the number of mature RNAs produced by genes transcribed by pol I and pol III and of most genes transcribed by pol II remains unchanged [10].

Chemical compound and disease context of Tetrahymena

• Furthermore, the strength of the guanosine-binding interaction, the stereospecificity for Rp-phosphorothioate at the cleavage site, and the 10(3)-fold slower cleavage with a deoxyribonucleoside leaving group are properties conserved between the Anabaena and Tetrahymena ribozymes [11].
• The phosphoenolpyruvate mutase gene from Tetrahymena pyriformis has been cloned and overexpressed in Escherichia coli [12].
• Comparison of the predicted peptide sequence of pSR132 with other proteins compiled in the NBRF data base revealed significant homology with carboxyphosphonoenolpyruvate mutase and phosphoenolpyruvate mutase from Streptomyces hygroscopicus and Tetrahymena pyriformis, respectively [13].
• Quantitative structure--toxicity relationships using TOPS-MODE. 1. Nitrobenzene toxicity to Tetrahymena pyriformis [14].
• The FDNB-difference, dye-binding lysine, Tetrahymena and Pediococcus methods all seriously underestimated reactive or available lysine in heat-damaged milk powders [15].

Biological context of Tetrahymena

• We have developed an in vivo RNA splicing assay for the self-splicing rRNA intron of Tetrahymena thermophila using E. coli as the host [1].
• This sequence-specific attachment could enable group II introns to integrate into unrelated RNAs by reverse splicing, in a process similar to that described for the self-splicing Tetrahymena group I intron [16].
• The guanosine binding site of the Tetrahymena ribozyme [17].
• We show here that the sequences hybridizing to this probe are located at the telomeres of most, if not all, human chromosomes and are similar to the Tetrahymena telomeric-repeat component of the probe [18].
• Sequence of a ribosomal RNA gene intron from Tetrahymena [19].

Anatomical context of Tetrahymena

• This establishes that the spliceosome is a metalloenzyme and demonstrates a direct parallel with the catalytic strategy used by the self-splicing group I intron from Tetrahymena [20].
• We transform Tetrahymena with marked glutamine tRNAs and quantitate their level of accumulation in mitochondria [21].
• Antibodies directed against whole histone and purified lysine-rich histone H1 extracted from isolated macronuclei of the ciliate Tetrahymena were obtained and conjugated to fluorescein isothiocyanate [22].
• Fractionation of Tetrahymena ciliary membranes with triton X-114 and the identification of a ciliary membrane ATPase [23].
• Extracts of rat tissues, Euglena gracilis, Tetrahymena pyriformis, HeLa cells, and spinach also can catalyze the reduction of methionine sulfoxide residues in protein [24].

Associations of Tetrahymena with chemical compounds

• Tetrahymena thermophila cells transferred from growth medium into a dilute salt (starvation) medium shortly (approximately 6-8 hrs) become more resistant to the in vivo inhibitory effects of the antibiotics cycloheximide, tetracycline and emetine [25].
• Efficient UV-induced cross-links are observed in Oxy-4 and the related sequence from Tetrahymena (d(T2G4)4 = Tet-4), and join thymidine residues in different repeats [26].
• We report here experiments which show that the ciliate Tetrahymena thermophila (formerly T. pyriformis, syngen 1) is sensitive to the paromamine-containing aminoglycoside antibiotics [27].
• Thus although it was shown twenty years ago that the isotope label from [14C]glucose or from [32P]phosphoenolpyruvate is incorporated into 2-aminoethylphosphonate by the protozoan Tetrahymena pyriformis, the presumed stoichiometric transformation of phosphoenolpyruvate to phosphonopyruvate has never been demonstrated [28].
• Structure of Tetrahymena GCN5 bound to coenzyme A and a histone H3 peptide [29].

Gene context of Tetrahymena

• Template definition by Tetrahymena telomerase reverse transcriptase [30].
• In contrast, the expression of TLP1/TP1, the human homologue of Tetrahymena p80 telomerase subunit, was similar in all of these samples [31].
• Human p300/CBP-associating factor, human GCN5, and tetrahymena GCN5 displayed dissociation constants (K(d)) for acetyl-CoA of 0.64 +/- 0.12, 0.56 +/- 0.15, and 0.62 +/- 0.17 microm, respectively [32].
• The yeast proteins to which the Tetrahymena cnjC is homologous are the 40 kd protein of RNA polymerases I and III (coded for by gene RPC40) and the third-largest subunit of RNA polymerase II (coded for by gene RPB3) [33].
• MBP-Tel2p did not bind duplex telomeric DNA repeats from vertebrates, Tetrahymena or Oxytricha [34].

Analytical, diagnostic and therapeutic context of Tetrahymena

• In the self-splicing group I intron from Tetrahymena thermophila, several divalent metals can serve structural roles, but only Mg2+ and Mn2+ promote splice-site cleavage and exon ligation [35].
• Sequence analysis of genes in four species of ciliated protozoa and analysis of tRNAs in Tetrahymena has demonstrated that TAG and TAA encode glutamine or glutamic acid in these organisms and TGA is the only stop codon [36].
• The formation of individual tertiary contacts of the Tetrahymena L-21 Sca I ribozyme has been monitored by hydroxyl radical footprinting and its global conformation by analytical ultracentrifugation as a function of monovalent ion concentration in the absence of divalent ions [37].
• Recombinant Tetrahymena telomerase eluted from a gel filtration column at the size of a monomeric complex (one RNA plus one TERT), and those fractions showed processive telomerase activity [38].
• Crystals by design: a strategy for crystallization of a ribozyme derived from the Tetrahymena group I intron [39].

References