A promotor directing alpha-amanitin-sensitive transcription of GARP, the major surface antigen of insect stage Trypanosoma congolense

Nucleic Acids Res. 1996 Jan 15;24(2):272-81. doi: 10.1093/nar/24.2.272.

Abstract

The major surface antigen of procyclic and epimastigote forms of Trypanosoma congolense in the tsetse fly is GARP (glutamic acid/alanine-rich protein), which is thought to be the analogue of procyclin/PARP in Trypanosoma brucei. We have studied two T.congolense GARP loci (the 4.3 and 4.4 loci) whose transcription is alpha-amanitin sensitive. Whilst a transcriptional gap 5' of the first GARP gene in the cloned region of the 4.4 locus could not be detected, such a gap was present in the 5' flank of the first GARP gene in the 4.3 locus. We have located a GARP transcription start site and, using reporter gene constructs containing a putative GARP promoter region in transient transfection studies, we have demonstrated promoter activity for the test region in T.congolense. There are species-specific differences in sequences regulating expression of the two major surface antigens, GARP and procyclin/PARP: the GARP promoter is inactive in T.brucei while the procyclin/PARP promoter is inactive in T.congolense. We have defined the splice acceptor site for the 4.3 GARP gene by sequencing and by 5' RT-PCR and demonstrated microheterogeneity in GARP polyadenylation by 3' RT-PCR. It appears that some GARP and procyclin/PARP RNA processing signals, although similar, are also species-specific.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amanitins / pharmacology*
  • Animals
  • Antigens, Protozoan / genetics
  • Base Sequence
  • Gene Expression Regulation
  • Genes, Protozoan / genetics
  • Membrane Glycoproteins / genetics*
  • Molecular Sequence Data
  • Promoter Regions, Genetic / genetics*
  • Protozoan Proteins / genetics*
  • RNA Processing, Post-Transcriptional / genetics
  • RNA Splicing / genetics
  • RNA, Messenger / analysis
  • RNA, Messenger / metabolism
  • RNA, Protozoan / analysis
  • RNA, Protozoan / metabolism
  • Species Specificity
  • Transcription, Genetic / drug effects*
  • Trypanosoma brucei brucei / genetics
  • Trypanosoma congolense / genetics*
  • Trypanosoma congolense / immunology

Substances

  • Amanitins
  • Antigens, Protozoan
  • GARP protein, Trypanosoma
  • Membrane Glycoproteins
  • Protozoan Proteins
  • RNA, Messenger
  • RNA, Protozoan
  • procyclic acidic repetitive protein, Trypanosoma

Associated data

  • GENBANK/U35672
  • GENBANK/U35856