The PARP promoter of Trypanosoma brucei is developmentally regulated in a chromosomal context
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
African trypanosomes are extracellular protozoan parasites that are transmitted from one mammalian host to the next by tsetse flies. Bloodstream forms express variant surface glycoprotein (VSG); the tsetse fly (procyclic) forms express instead the procyclic acidic repetitive protein (PARP). PARP mRNA is abundant in procyclic forms and almost undetectable in blood-stream forms. Post-transcriptional mechanisms are mainly responsible for PARP mRNA regulation but results of nuclear run-on experiments suggested that transcription might also be regulated. We measured the activity of genomically-integrated PARP, VSG and rRNA promoters in permanently-transformed blood-stream and procyclic form trypanosomes, using reporter gene constructs that showed no post-transcriptional regulation. When the constructs were integrated in the rRNA non-transcribed spacer, the ribosomal RNA and VSG promoters were not developmentally regulated, but integration at the PARP locus reduced rRNA promoter activity in bloodstream forms. PARP promoter activity was 5-fold down-regulated in bloodstream forms when integrated at either site. Regulation was probably at the level of transcriptional initiation, but elongation through plasmid vector sequences was also reduced.
Originalsprog | Engelsk |
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Tidsskrift | Nucleic Acids Research |
Vol/bind | 24 |
Udgave nummer | 7 |
Sider (fra-til) | 1202-11 |
Antal sider | 10 |
ISSN | 0305-1048 |
Status | Udgivet - 1 apr. 1996 |
ID: 138821807