The PARP promoter of Trypanosoma brucei is developmentally regulated in a chromosomal context

Nucleic Acids Res. 1996 Apr 1;24(7):1202-11. doi: 10.1093/nar/24.7.1202.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • DNA Primers / chemistry
  • Gene Expression Regulation, Developmental*
  • Membrane Glycoproteins / genetics*
  • Molecular Sequence Data
  • Promoter Regions, Genetic*
  • Protozoan Proteins*
  • RNA, Ribosomal / genetics
  • Transcription, Genetic
  • Trypanosoma brucei brucei / genetics*
  • Tubulin / genetics


  • DNA Primers
  • Membrane Glycoproteins
  • Protozoan Proteins
  • RNA, Ribosomal
  • Tubulin
  • procyclic acidic repetitive protein, Trypanosoma