Expression of Trypanosoma cruzi surface antigen FL-160 is controlled by elements in the 3' untranslated, the 3' intergenic, and the coding regions.
Mol Biochem Parasitol
; 102(1): 53-66, 1999 Jul 30.
Article
em En
| MEDLINE
| ID: mdl-10477176
ABSTRACT
The FL-160 surface antigen gene family of T. cruzi consists of hundreds of members of 160 kDa glycoproteins expressed in trypomastigotes, but not in epimastigotes. Steady-state levels of FL-160 mRNA were 80 to 100-fold higher in trypomastigotes than in epimastigotes, yet transcription rates were equivalent between the lifecycle stages. Luciferase reporter constructs demonstrated that the 3' untranslated region (UTR) and intergenic region (IR) following the coding sequence of FL-160 was sufficient to generate 8-fold higher luciferase expression in trypomastigotes compared with epimastigotes. Transfection of 3' UTR/IR deletion constructs revealed cis-acting elements which conferred a trypomastigote-specific expression pattern similar to that of FL-160. Parasites treated with translation and transcription inhibitors, cyclohexamide and Actinomycin D, respectively, displayed a stage-specific pattern of FL-160 mRNA degradation. Epimastigotes, but not trypomastigotes, treated with the inhibitors accumulated a 1.4 Kb FL-160 cleavage product. The cleavage site mapped to a 31 base poly-purine tract in the FL-160 coding region. The first 526 aa of FL-160, containing the 31 base poly-purine tract and several smaller tracts, were fused to green fluorescent protein (GFP) and expressed from the T. cruzi tubulin locus. Stable transformants expressed 4-fold more FL-160GFP fusion mRNA and 12-fold more fusion protein in the trypomastigote stage than in the epimastigote stage suggesting post-transcriptional and translational control elements. These data reveal at least two distinct control mechanisms for trypomastigote-specific expression of FL-160 surface glycoproteins, one involving the 3' UTR/IR and one involving the coding region of FL-160.
Buscar no Google
Base de dados:
MEDLINE
Assunto principal:
Trypanosoma cruzi
/
Regulação da Expressão Gênica
/
Regiões 3' não Traduzidas
/
Antígenos de Protozoários
Limite:
Animals
Idioma:
En
Revista:
Mol Biochem Parasitol
Ano de publicação:
1999
Tipo de documento:
Article
País de afiliação:
Estados Unidos