Supervisor: prof. Jiří Fajkus

Annotation: The origin of linear chromosomes associated with divergence of eukaryotes led to the evolution of mechanisms counteracting the incomplete replication of chromosome ends––the telomeres. The most common mechanism to overcome the end-replication problem involves a ribonucleoprotein complex enzyme––telomerase. Telomerase elongates the 3_-end of telomeric DNA using the catalytic activity of its core protein subunit––telomerase reverse transcriptase (TERT) – which can repeatedly add a short DNA stretch to telomeric DNA. The sequence added by telomerase is directed by a template region in telomerase RNA (TR), the other core telomerase subunit. In addition to these two core subunits, the complex of telomerase involves several other associated proteins which affect various steps of telomerase function in vivo, as, e.g. telomerase assembly, trafficking, localisation, processivity, or its recruitment to telomeres. Importantly, TR functions not only as the telomerase templating subunit but also as a scaffold to assemble the entire functional telomerase complex. Recently we identified genuine TRs across land plants (Fajkus et al., 2019). This opened a possibility to investigate plant telomere and telomerase structure, function and evolution and elucidate the principle of its reversible regulation in plants, contrary to its permanent developmental silencing is humans.

Recommended literature:

Fajkus P., Peška V. et al.: Telomerase RNAs in land plants. Nucleic Acids Res. 47:18, 9842–9856 (2019).

Procházková Schrumpfová, P.; Fojtová, M.; Fajkus, J. Telomeres in Plants and Humans: Not So Different, Not So Similar. Cells 2019, 8, 58.

Keywords: Telomeres, telomerase, RNA-protein interactions, bioinformatics, evolution

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