Characterization of telomeres and telomerase from the single-celled eukaryote Giardia intestinalis
Language English Country Netherlands Media print-electronic
Document type Journal Article, Research Support, Non-U.S. Gov't
PubMed
27638151
DOI
10.1016/j.molbiopara.2016.09.003
PII: S0166-6851(16)30126-8
Knihovny.cz E-resources
- Keywords
- Chromosomes, Giardia, TRAP assay, Telomerase, Telomeres, Terminal restriction fragment,
- MeSH
- Enzyme Activation MeSH
- Cell Line MeSH
- Giardia lamblia enzymology genetics MeSH
- Giardiasis parasitology MeSH
- Telomere Homeostasis MeSH
- In Situ Hybridization, Fluorescence MeSH
- Humans MeSH
- Mitosis genetics MeSH
- Protein Subunits metabolism MeSH
- Repetitive Sequences, Nucleic Acid MeSH
- Telomerase chemistry metabolism MeSH
- Telomere genetics MeSH
- Protein Transport MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Protein Subunits MeSH
- Telomerase MeSH
The ends of linear chromosomes, telomeres, are most commonly maintained by the enzyme telomerase. Our study presents the characteristics of telomeres and telomerase from the single-celled parasitic eukaryote Giardia intestinalis. Using fluorescence in situ hybridization, we localized telomeres during all stages of the trophozoite cell cycle and demonstrated differences in the observed number of telomeric foci, indicating telomere clustering. The length of Giardia telomeres was determined in different cell lines derived from WB clinical isolate using terminal restriction fragment analysis and ranged from 0.5 to 2.5kb; moreover, a BAL-31 digestion experiment did not reveal any long interstitial telomeric sequences in the genome. Despite the absence of the specific T motif in the telomerase catalytic subunit, the presence of an active telomerase enzyme synthesising telomeric repeats in Giardia was proved by a Telomere repeat amplification protocol assay, and its localization in nuclei was determined by the expression of recombinant GiTERT. Except for the Giardia-type TAGGG telomeric repeat, Giardia telomerase was proved to synthesize in vitro also other repeat variants, TAAGG and TAAGGG. In summary, despite its unusual characteristics, including a structurally divergent but active telomerase, unique terminal sequences and relatively short telomeres, the present data support the view that the chromosomal termini in Giardia are maintained in a conservative manner that is common to other eukaryotes.
References provided by Crossref.org
High quality genome assembly of the amitochondriate eukaryote Monocercomonoides exilis
Origin, Diversity, and Evolution of Telomere Sequences in Plants