Evidences for insulator activity of the 5'UTR of the Drosophila melanogaster LTR-retrotransposon ZAM.
Insulators or chromatin boundary are DNA elements that organize the genome into discrete regulatory domains by limiting the actions of enhancers and silencers through a "positional-blocking mechanism". The role of these sequences, both in modulation of the enhancers range of action (enhancer-promoter selectivity) and in the organization of the chromatin in functional domains, is emerging strongly in these last years. There is a great interest in identifying new insulators because deeper knowledge of these elements can help understand how cis-regulatory elements coordinate the expression of the target genes. However, while insulators are critical in gene regulation and genome functioning, only a few have been reported so far. Here, we describe a new insulator sequence that is located in the 5'UTR of the Drosophila retrotransposon ZAM. We have used an "enhancer-blocking assay" to test its effects on the activity of the enhancer in transiently transfected Drosophila S2R(+) cell line. Moreover, we show that the new insulator is able to affect significantly the enhancer-promoter interaction in the human cell line HEK293. These results suggest the possibility of employing the ZAM insulator in gene transfer protocols from insects to mammals in order to counteract the transgene positional and genotoxic effects.
Minervini
Crescenzio Francesco
CF
Department of Genetics and Microbiology, University of Bari, Via Amendola 165/A, 70100, Bari, Italy.
Ruggieri
Simona
S
Traversa
Michele
M
D'Aiuto
Leonardo
L
Marsano
Rene' Massimiliano
RM
Leronni
Daniela
D
Centomani
Isabella
I
De Giovanni
Claudio
C
Viggiano
Luigi
L
D020121:5' Untranslated Regions / Q000235:genetics*; D000818:Animals; D002460:Cell Line; D029721:Drosophila Proteins / Q000235:genetics; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics*; D006801:Humans; D038101:Insulator Elements / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics; D018626:Retroelements / Q000235:genetics*; D020079:Terminal Repeat Sequences / Q000235:genetics*; D014162:Transfection
D020121:5' Untranslated Regions; D029721:Drosophila Proteins; D012097:Repressor Proteins; D018626:Retroelements; C083738:su(Hw) protein, Drosophila