Identification of a polypeptide containing Tudor and staphyloccocal nuclease-like domains as the sequence-specific binding protein to the upstream regulatory element 1 of Entamoeba histolytica

• Published in: International journal for parasitology 2011-06, Vol.41 (7), p.775-782
• Main Authors: Calixto-Gálvez, Mercedes, Romero-Díaz, Mónica, García-Muñoz, Alejandro, Salas-Casas, Andrés, Pais-Morales, Jonnatan, Galván, Iván J., Orozco, Esther, Rodríguez, Mario A.
• Format: Article
• Language: English
• Subjects: amebiasis; Amino Acid Motifs; antibodies; Biological and medical sciences; Blotting, Western; Cell Nucleus - chemistry; cytoplasm; Cytoplasm - chemistry; DNA; DNA, Protozoan - genetics; DNA, Protozoan - metabolism; DNA-binding domain; DNA-binding domains; DNA-binding proteins; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; electrophoresis; Electrophoretic Mobility Shift Assay; Entamoeba histolytica; Entamoeba histolytica - genetics; Entamoeba histolytica - metabolism; Entamoeba histolytica - physiology; fluorescent antibody technique; Fundamental and applied biological sciences. Psychology; gene expression; Gene Expression Regulation; genes; humans; Life cycle. Host-agent relationship. Pathogenesis; Microscopy, Fluorescence; parasites; pathogenicity; Protein Binding; Protein Structure, Tertiary; Protozoa; Protozoan Proteins - genetics; Protozoan Proteins - metabolism; rabbits; recombinant proteins; Regulatory Elements, Transcriptional; regulatory proteins; Sequence Homology, Amino Acid; Transcription factor; transcription factors; TSN-like protein; Upstream regulatory element; Western blotting
• ISSN: 0020-7519; 1879-0135
• DOI: 10.1016/j.ijpara.2011.02.002

[Display omitted] ► An Entamoeba histolytica protein with Tudor and SNase domains binds to the regulatory element URE1. ► EhURE1BP has one Tudor and five SNase domains. ► The C-terminus of EhURE1BP contains the DNA-binding domain. Transcription initiation is the most regulated stage for the control of gene expression. This event requires that a complex of proteins called transcription factors bind to DNA through cis-regulatory elements located in the gene promoters. However, little is known about transcription regulation in Entamoeba histolytica, the protozoan parasite responsible for human amoebiasis. Some genes encoding for proteins involved in the parasite pathogenicity contain specific upstream regulatory elements (URE1–URE5) in their promoters. Here, we identified the protein that specifically binds to the URE1 sequence (EhURE1BP). This protein contains five SNase domains and one Tudor motif, and has 21% identity and 36% similarity to the multifunctional eukaryotic protein known as the protein containing Tudor and staphyloccocal nuclease-like domains (TSN). To obtain antibodies against EhURE1BP, the recombinant protein was expressed and immunised in rabbits. Western blot and immunofluorescence assays showed that EhURE1BP is located in both nuclei and cytoplasm. Electrophoretic mobility shift assays and supershift assays demonstrated that EhURE1PB specifically binds to URE1 and that the C-terminus that includes the Tudor motif contains the DNA-binding domain of this protein. Results suggest that this TSN-like protein is the transcription factor that activates the transcription of some pathogenicity-related genes of E. histolytica.