Identification of a Nuclear Protein in Trypanosoma Brucei With Homology to RNA-binding Proteins From Cis-Splicing Systems

Mol Biochem Parasitol. 1998 Nov 30;97(1-2):1-11. doi: 10.1016/s0166-6851(98)00118-2.

Abstract

Gene expression in trypanosomes is controlled at the level of pre-mRNA maturation via trans-splicing and polyadenylation and through changes in mRNA stability. To identify the trans- acting factors involved in this regulation, we have used a degenerate PCR approach to clone genes encoding the RNA recognition motif (RRM) consensus. We have identified a single-copy gene encoding a protein (designated RRM1) which contains three consensus RRM motifs, two tandem copies of a retroviral gag-like CCHC 'zinc finger' and an arginine-serine (RS) rich region. Western blotting indicates that RRM1 is expressed in both procyclic and bloodstream-form trypanosomes and has an apparent mobility on SDS-PAGE of ca. 70 Kd. RRM1 is localized in the trypanosome nucleus in substructures which may be functionally analogous to the 'speckles' associated with cis-splicing in higher eukaryotic cells. The structure of RRM1, its pattern of expression and its intracellular location suggest that it may play a role in trans-splicing.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Blotting, Western
  • Cloning, Molecular
  • Fluorescent Antibody Technique, Indirect
  • Genes, Protozoan
  • Molecular Sequence Data
  • Nuclear Proteins / analysis
  • Nuclear Proteins / genetics*
  • Open Reading Frames / genetics
  • Polymerase Chain Reaction / methods
  • Protozoan Proteins / analysis
  • Protozoan Proteins / genetics*
  • RNA, Protozoan / analysis
  • RNA-Binding Proteins / analysis
  • RNA-Binding Proteins / genetics*
  • Sequence Alignment
  • Trans-Splicing / genetics*
  • Trypanosoma brucei brucei / chemistry
  • Trypanosoma brucei brucei / genetics*

Substances

  • Nuclear Proteins
  • Protozoan Proteins
  • RNA, Protozoan
  • RNA-Binding Proteins
  • RRM1 protein, Trypanosoma brucei

Associated data

  • GENBANK/U22048