Transcription of Leishmania major Friedlin chromosome 1 initiates in both directions within a single region

Mol Cell. 2003 May;11(5):1291-9. doi: 10.1016/s1097-2765(03)00143-6.

Abstract

Almost nothing is known about the sequences involved in transcription initiation of protein-coding genes in the parasite Leishmania. We describe here the transcriptional analysis of chromosome 1 (chr1) from Leishmania major Friedlin (LmjF) which encodes the first 29 genes on one DNA strand, and the remaining 50 on the opposite strand. Strand-specific nuclear run-on assays showed that a low level of nonspecific transcription probably takes place over the entire chromosome, but an approximately 10-fold higher level of coding strand-specific RNA polymerase II (Pol II)-mediated transcription initiates within the strand-switch region. 5' RACE studies localized the initiation sites to a <100 bp region. Transfection studies support the presence of a bidirectional promoter within the strand-switch region, but suggest that other factors are also involved in Pol II transcription. Thus, while in most eukaryotes each gene possesses its own promoter, a single region seems to drive the expression of the entire chr1 in LmjF.

Publication types

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

MeSH terms

  • Animals
  • Base Sequence / genetics
  • Chromosome Mapping
  • Chromosomes / genetics*
  • Chromosomes / radiation effects
  • Gene Expression Regulation / genetics*
  • Gene Expression Regulation / radiation effects
  • Genes, Regulator / genetics
  • Genes, Regulator / radiation effects
  • Leishmania / genetics*
  • Leishmania / metabolism
  • Molecular Sequence Data
  • Promoter Regions, Genetic / genetics*
  • Promoter Regions, Genetic / radiation effects
  • RNA / biosynthesis*
  • RNA / genetics
  • RNA Polymerase II / genetics*
  • RNA Splice Sites / genetics
  • Transcription, Genetic / genetics*
  • Transcription, Genetic / radiation effects
  • Ultraviolet Rays

Substances

  • RNA Splice Sites
  • RNA
  • RNA Polymerase II