Mechanisms of developmental regulation in Trypanosoma brucei: a polypyrimidine tract in the 3'-untranslated region of a surface protein mRNA affects RNA abundance and translation

Nucleic Acids Res. 1997 Aug 1;25(15):3017-26. doi: 10.1093/nar/25.15.3017.


Salivarian trypanosomes are extracellular parasites of mammals that are transmitted by tsetse flies. The procyclic acidic repetitive proteins (PARPs) are the major surface glycoproteins of the form of Trypanosoma brucei that replicates in the fly. The abundance of PARP mRNA and protein is very strongly regulated, mostly at the post-transcriptional level. The 3'-untranslated regions of two PARP genes are of similar lengths, but are dissimilar in sequence apart from a 16mer stem-loop that stimulates translation and a 26mer polypyrimidine tract. Addition of either of these PARP 3'-untranslated regions immediately downstream of a reporter gene resulted in developmental regulation mimicking that of PARP. We show that the PARP 3'-UTR reduces RNA stability and translation in bloodstream forms and that the 26mer polypyrimidine tract is necessary for both effects.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Gene Expression Regulation, Developmental*
  • Membrane Glycoproteins / genetics*
  • Molecular Sequence Data
  • Mutagenesis
  • Protein Biosynthesis*
  • Protozoan Proteins / genetics*
  • Pyrimidines*
  • RNA Splicing
  • RNA, Messenger / metabolism
  • RNA, Protozoan / metabolism
  • Trypanosoma brucei brucei / genetics*


  • Membrane Glycoproteins
  • Protozoan Proteins
  • Pyrimidines
  • RNA, Messenger
  • RNA, Protozoan
  • procyclic acidic repetitive protein, Trypanosoma