GREM, a technique for genome-wide isolation and quantitative analysis of promoter active repeats.
We developed a technique called GREM (Genomic Repeat Expression Monitor) that can be applied to genome-wide isolation and quantitative analysis of any kind of transcriptionally active repetitive elements. Briefly, the technique includes three major stages: (i) generation of a transcriptome wide library of cDNA 5' terminal fragments, (ii) selective amplification of repeat-flanking genomic loci and (iii) hybridization of the cDNA library (i) to the amplicon (ii) with subsequent selective amplification and cloning of the cDNA-genome hybrids. The sequences obtained serve as 'tags' for promoter active repetitive elements. The advantage of GREM is an unambiguous mapping of individual promoter active repeats at a genome-wide level. We applied GREM for genome-wide experimental identification of human-specific endogenous retroviruses and their solitary long terminal repeats (LTRs) acting in vivo as promoters. Importantly, GREM tag frequencies linearly correlated with the corresponding LTR-driven transcript levels found using RT-PCR. The GREM technique enabled us to identify 54 new functional human promoters created by retroviral LTRs.
Buzdin
Anton
A
Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 16/10 Miklukho-Maklaya, Moscow 117997, Russia. anton@humgen.siobc.ras.ru
Kovalskaya-Alexandrova
Elena
E
Gogvadze
Elena
E
Sverdlov
Eugene
E
D020077:Endogenous Retroviruses / Q000235:genetics*; D015723:Gene Library; D023281:Genomics / Q000379:methods*; D006801:Humans; D011401:Promoter Regions, Genetic; D020079:Terminal Repeat Sequences; D015533:Transcriptional Activation