title: Peculiarities of Yeasts and Human Telomerase RNAs Processing.
abstract: Telomerase is one of the major components of the telomeres -- linear eukaryotic chromosome ends - maintenance system. Linear chromosomes are shortened during each cell division due to the removal of the primer used for DNA replication. Special repeated telomere sequences at the very ends of linear chromosomes prevent the deletion of genome information caused by primer removal. Telomeres are shortened at each replication round until it becomes critically short and is no longer able to protect the chromosome in somatic cells. At this stage, a cell undergoes a crisis and usually dies. Rare cases result in telomerase activation, and the cell gains unlimited proliferative capacity. Special types of cells, such as stem, germ, embryonic cells and cells from tissues with a high proliferative potential, maintain their telomerase activity indefinitely. The telomerase is inactive in the majority of somatic cells. Telomerase activityin vitrorequires two key components: telomerase reverse transcriptase and telomerase RNA. In cancer cells, telomerase reactivates due to the expression of the reverse transcriptase gene. Telomerase RNA expresses constitutively in the majority of human cells. This fact suggests that there are alternative functions to telomerase RNA that are unknown at the moment. In this manuscript, we review the biogenesis of yeasts and human telomerase RNAs thanks to breakthroughs achieved in research on telomerase RNA processing by different yeasts species and humans in the last several years.
authors.affiliation: Lomonosov Moscow State University, Chemistry Department, Leninskie gory, 1, bld. 3, Moscow, 119991 , Russia ; Lomonosov Moscow State University, Belozersky Institute of physico-chemical biology, Leninskie gory, 1, bld. 40, Moscow, 119991, Russia.
authors.forename: M P
authors.initials: MP
authors.lastname: Rubtsova
authors.affiliation: Lomonosov Moscow State University, Chemistry Department, Leninskie gory, 1, bld. 3, Moscow, 119991 , Russia.
authors.forename: D P
authors.initials: DP
authors.lastname: Vasilkova
authors.affiliation: Skolkovo Institute of Science and Technology, Skolkovo Innovation Center, bld. 3, Moscow, 143026 , Russia.
authors.forename: Yu V
authors.initials: YV
authors.lastname: Naraykina
authors.affiliation: Lomonosov Moscow State University, Chemistry Department, Leninskie gory, 1, bld. 3, Moscow, 119991 , Russia ; Lomonosov Moscow State University, Belozersky Institute of physico-chemical biology, Leninskie gory, 1, bld. 40, Moscow, 119991, Russia ; Lomonosov Moscow State University, Faculty of bioengineering and bioinformatics, Leninskie gory, 1, bld. 73, Moscow, 119991, Russia.
authors.forename: O A
authors.initials: OA
authors.lastname: Dontsova
keywords: exosome; processing; splicing telomerase; telomerase RNA; transcription