Trypanosoma cruzi: Modulation of HSP70 mRNA stability by untranslated regions during heat shock

• Published in: Experimental parasitology 2010-10, Vol.126 (2), p.245-253
• Main Authors: Rodrigues, Deivid C, Silva, Rosane, Rondinelli, Edson, Ürményi, Turán P
• Format: Article
• Language: English
• Subjects: 3' Untranslated Regions - genetics; 3' Untranslated Regions - physiology; 5' Untranslated Regions - genetics; 5' Untranslated Regions - physiology; Base Sequence; Biological and medical sciences; Blotting, Northern; Chloramphenicol O-Acetyltransferase - genetics; Chloramphenicol O-Acetyltransferase - metabolism; DNA, Protozoan - chemistry; DNA, Protozoan - genetics; DNA, Protozoan - metabolism; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation - physiology; Gene regulation; Half-Life; Hot Temperature; HSP70; HSP70 Heat-Shock Proteins - genetics; HSP70 Heat-Shock Proteins - metabolism; Life cycle. Host-agent relationship. Pathogenesis; mRNA stability; Plasmids - genetics; Plasmids - metabolism; Protozoa; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - genetics; RNA, Messenger - metabolism; Transfection; Trypanosoma cruzi; Trypanosoma cruzi - genetics; Trypanosoma cruzi - metabolism
• ISSN: 0014-4894; 1090-2449
• DOI: 10.1016/j.exppara.2010.05.009

Gene regulation in trypanosomatids occurs mainly by post-transcriptional mechanisms modulating mRNA stability and translation. We have investigated heat shock protein (HSP) 70 gene regulation in Trypanosoma cruzi, the causal agent of Chagas’ disease. The HSP70 mRNA’s half-life increases after heat shock, and the stabilization is dependent on protein synthesis. In a cell-free RNA decay assay, a U-rich region in the 3′ untranslated region (UTR) is a target for degradation, which is reduced when in the presence of protein extracts from heat shocked cells. In a transfected reporter gene assay, both the 5′- and 3′-UTRs confer temperature-dependent regulation. Both UTRs must be present to increase mRNA stability at 37 °C, indicating that the 5′- and 3′-UTRs act cooperatively to stabilize HSP70 mRNA during heat shock. We conclude that HSP70 5′- and 3′-UTRs regulate mRNA stability during heat shock in T. cruzi.