Beyond the ends: telomeric repeats and their hidden functions
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Year of publication | 2024 |
Type | Conference abstract |
MU Faculty or unit | |
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Description | Physical ends of linear chromosomes, named telomeres, consist in most plant species of telomeric repeats (TTTAGGG)n. However, telomeric repeats are not exclusively localized at the telomeres but also internally, either as a long telomeric DNA tract called interstitial telomeric sequences (ITSs) or as short repeats (telo-boxes) prevalently localized in gene promoters [1]. Telomeric repeat motifs are recognized by plant-specific TRB (Telomere Repeat Binding) proteins. TRB proteins possess a Myb-domain like human TRF1/2, but unlike their human counterparts, TRBs also contain an H1-like domain. TRBs not only interact with the catalytic subunit of telomerase and other telomere/telomerase-associated proteins, but they may also serve as epigenetic regulators. We have clarified that TRBs emerged in evolution after the transition to a terrestrial habitat, and we have completed characterization of all TRB family members in Arabidopsis [2]. We have also helped to show that the accessibility of TRB1 to telomeres and ITSs may be restricted by H1 [3]. To elucidate the precise localization of telo-boxes within gene promoters, we developed software named GOLEM (Gene regulatOry eLEMents, www.golem.ncbr.muni.cz). In GOLEM, the distribution and frequency of any motif of interest in relevant plant genomes, in the vicinity of the transcription start site (TSS), may be visualized in relation to the transcript levels of particular genes in different tissues. Novel findings regarding the role of telomeric repeats and TRB proteins throughout evolution will be discussed. |
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