title: The Tudor Staphylococcal Nuclease Protein ofEntamoeba histolyticaParticipates in Transcription Regulation and Stress Response.
abstract: Entamoeba histolyticais the protozoa parasite responsible of human amoebiasis, disease that causes from 40,000 to 100,000 deaths annually worldwide. However, few are known about the expression regulation of molecules involved in its pathogenicity. Transcription of some virulence-related genes is positively controlled by the cis-regulatory element named URE1. Previously we identified the transcription factor that binds to URE1, which displayed a nuclear and cytoplasmic localization. This protein belongs to the Tudor Staphyococcal nuclease (TSN) family, which in other systems participates in virtually all pathways of gene expression, suggesting that this amoebic transcription factor (EhTSN; former EhURE1BP) could also play multiple functions inE. histolytica. The aim of this study was to identify the possible cellular events where EhTSN is involved. Here, we found that EhTSN in nucleus is located in euchromatin and close to, but not into, heterochromatin. We also showed the association of EhTSN with proteins involved in transcription and that the knockdown of EhTSN provokes a diminishing in the mRNA level of theEhRabBgene, which in its promoter region contains the URE1 motif, confirming that EhTSN participates in transcription regulation. In cytoplasm, this protein was found linked to the membrane of small vesicles and to plasma membrane. Through pull-down assays and mass spectrometry we identity thirty two candidate proteins to interact with EhTSN. These proteins participate in transcription, metabolism, signaling, and stress response, among other cellular processes. Interaction of EhTSN with some candidate proteins involved in metabolism, and signaling was validated by co-immunoprecipitation or co-localization. Finally we showed the co-localization of EhTSN and HSP70 in putative stress granules during heat shock and that the knockdown of EhTSN increases the cell death during heat shock treatment, reinforcing the hypothesis that EhTSN has a role during stress response. All data support the proposal that EhTSN is a multifunctional protein ofE. histolytica.
authors.affiliation: Departamento de Infectómica y Patogénesis Molecular, CINVESTAV-IPN Ciudad de México, Mexico.
authors.forename: Javier
authors.initials: J
authors.lastname: Cázares-Apátiga
authors.affiliation: Departamento de Infectómica y Patogénesis Molecular, CINVESTAV-IPN Ciudad de México, Mexico.
authors.forename: Christian
authors.initials: C
authors.lastname: Medina-Gómez
authors.affiliation: Departamento de Infectómica y Patogénesis Molecular, CINVESTAV-IPN Ciudad de México, Mexico.
authors.forename: Bibiana
authors.initials: B
authors.lastname: Chávez-Munguía
authors.affiliation: Departamento de Infectómica y Patogénesis Molecular, CINVESTAV-IPN Ciudad de México, Mexico.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Calixto-Gálvez
authors.affiliation: Departamento de Infectómica y Patogénesis Molecular, CINVESTAV-IPN Ciudad de México, Mexico.
authors.forename: Esther
authors.initials: E
authors.lastname: Orozco
authors.affiliation: Departamento de Infectómica y Patogénesis Molecular, CINVESTAV-IPN Ciudad de México, Mexico.
authors.forename: Carlos
authors.initials: C
authors.lastname: Vázquez-Calzada
authors.affiliation: Departamento de Infectómica y Patogénesis Molecular, CINVESTAV-IPN Ciudad de México, Mexico.
authors.forename: Aarón
authors.initials: A
authors.lastname: Martínez-Higuera
authors.affiliation: Departamento de Infectómica y Patogénesis Molecular, CINVESTAV-IPN Ciudad de México, Mexico.
authors.forename: Mario A
authors.initials: MA
authors.lastname: Rodríguez
mesh_terms: D003001:Cloning, Molecular; D003593:Cytoplasm / Q000378:metabolism; D016054:DNA, Protozoan / Q000737:chemistry; D004748:Entamoeba histolytica / Q000201:enzymology* / Q000235:genetics* / Q000502:physiology* / Q000648:ultrastructure; D004926:Escherichia coli / Q000235:genetics; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D017125:Genes, Protozoan; D018869:Heat-Shock Response; D008836:Micrococcal Nuclease / Q000235:genetics*; D016253:Microscopy, Immunoelectron; D010829:Physiological Phenomena; D011485:Protein Binding; D015800:Protozoan Proteins / Q000235:genetics; D012333:RNA, Messenger; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D016054:DNA, Protozoan; D015800:Protozoan Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; D008836:Micrococcal Nuclease
keywords: Entamoeba histolytica biology; Tudor Staphylococcal Nuclease; interactome; multifunctional protein; pull-down assays