title: 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.
abstract: 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.
authors: Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, AP 14-740 México, DF 07000, Mexico.
authors: Mercedes
authors: M
authors: Calixto-Gálvez
authors: Mónica
authors: M
authors: Romero-Díaz
authors: Alejandro
authors: A
authors: García-Muñoz
authors: Andrés
authors: A
authors: Salas-Casas
authors: Jonnatan
authors: J
authors: Pais-Morales
authors: Iván J
authors: IJ
authors: Galván
authors: Esther
authors: E
authors: Orozco
authors: Mario A
authors: MA
authors: Rodríguez
mesh_terms: D020816:Amino Acid Motifs; D015153:Blotting, Western; D002467:Cell Nucleus / Q000737:chemistry; D003593:Cytoplasm / Q000737:chemistry; D016054:DNA, Protozoan / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D004748:Entamoeba histolytica / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D005786:Gene Expression Regulation; D008856:Microscopy, Fluorescence; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D050436:Regulatory Elements, Transcriptional; D017386:Sequence Homology, Amino Acid
chemical_list: D016054:DNA, Protozoan; D004268:DNA-Binding Proteins; D015800:Protozoan Proteins