Regulation of mammalian LINE1 retrotransposon transcription

In-depth investigation of genomes of higher eukaryotes and, especially, results of successful genome sequencing projects bring us over that not only unique DNA sequences but also multiple families of repeats possess certain functions and are not just junk DNA. LINE1 retrotransposons are mobile elements that account for about 1/5 of mammalian genomes and participate in the retrotransposition of cellular DNA, organization of chromatin structure, genome rearrangements, and regulation of gene transcription. LINE1 elements are also involved in recombination and repair processes. In this review, LINE1 retrotransposons structural organization, characteristics of action and mechanisms of tissue-specific transcription regulation are discussed.