Role of RNA polymerase III transcription factors in the selection of integration sites by the dictyostelium non-long terminal repeat retrotransposon TRE5-A.
Mol Cell Biol
; 26(22): 8242-51, 2006 Nov.
Article
in En
| MEDLINE
| ID: mdl-16982688
ABSTRACT
In the compact Dictyostelium discoideum genome, non-long terminal repeat (non-LTR) retrotransposons known as TREs avoid accidental integration-mediated gene disruption by targeting the vicinity of tRNA genes. In this study we provide the first evidence that proteins of a non-LTR retrotransposon interact with a target-specific transcription factor to direct its integration. We applied an in vivo selection system that allows for the isolation of natural TRE5-A integrations into a known genomic location upstream of tRNA genes. TRE5-A frequently modified the integration site in a way characteristic of other non-LTR retrotransposons by adding nontemplated extra nucleotides and generating small and extended target site deletions. Mutations within the B-box promoter of the targeted tRNA genes interfered with both the in vitro binding of RNA polymerase III transcription factor TFIIIC and the ability of TRE5-A to target these genes. An isolated B box was sufficient to enhance TRE5-A integration in the absence of a surrounding tRNA gene. The RNA polymerase III-transcribed ribosomal 5S gene recruits TFIIIC in a B-box-independent manner, yet it was readily targeted by TRE5-A in our assay. These results suggest a direct role of an RNA polymerase III transcription factor in the targeting process.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Transcription Factors
/
RNA Polymerase III
/
Gene Expression Regulation, Fungal
/
Retroelements
/
Terminal Repeat Sequences
/
Dictyostelium
Limits:
Animals
Language:
En
Journal:
Mol Cell Biol
Year:
2006
Document type:
Article
Affiliation country:
Germany