Amastin mRNA Abundance in Trypanosoma cruzi Is Controlled by a 3′-Untranslated Region Position-dependent cis-Element and an Untranslated Region-binding Protein

Autor: Bridget C. Coughlin, John E. Donelson, Louis V. Kirchhoff, Santuza M. R. Teixeira
Rok vydání: 2000
Předmět:
Zdroj: Journal of Biological Chemistry. 275:12051-12060
ISSN: 0021-9258
DOI: 10.1074/jbc.275.16.12051
Popis: The genome of Trypanosoma cruzi contains tandem arrays of alternating genes encoding amastin and tuzin. Amastin is a surface glycoprotein abundantly expressed on the intracellular mammalian amastigote form of the protozoan parasite, and tuzin is a G-like protein. We demonstrated previously that the amastin-tuzin gene cluster is polycistronically transcribed to an equal extent in all parasite life cycle stages. The steady state level of amastin mRNA, however, is 68-fold more abundant in amastigotes than in epimastigotes. Here we show that the half-life of amastin mRNA is 7 times longer in amastigotes than in epimastigotes. Linker replacement experiments demonstrate that the middle one-third of the 630-nucleotide 3'-untranslated region (UTR) is responsible for the amastin mRNA up-regulation. This positive effect is dependent on the distance of the 3'-UTR segment from the stop codon and the polyadenylation site as well as on its orientation. A protein or protein complex more abundant in amastigotes than in epimastigotes binds to this minimally defined 3'-UTR segment and may be involved in its regulatory function.
Databáze: OpenAIRE