title: Entamoeba histolytica: intracellular distribution of the sec61alpha subunit of the secretory pathway and down-regulation by antisense peptide nucleic acids.
abstract: The Sec61alpha protein is defined as a highly conserved essential integral component of the endoplasmic reticulum in eukaryotic cells. We report a detailed immunolocalization of the Entamoeba histolytica homologue of the Sec61alpha subunit (EhSec61alpha), which shows an irregular pattern throughout the cell and is also found on the cell surface, its effective down-regulation by means of antisense peptide nucleic acids and its effects on cell proliferation, subcellular distribution of two virulence factors, and the ability of the trophozoites to cause liver abscess in hamsters. Although Sec61alpha levels are specifically decreased in antisense PNA-treated trophozoites, which proliferate more slowly than the controls, mobilization of the cysteine protease 5 and amoebapore to the cell surface is not significantly impeded and the capacity to induce liver abscess in hamsters is largely unaffected. The implications of these findings are discussed in the context of the peculiar cell biology of E. histolytica.
authors.affiliation: Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Mexico.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Sánchez
authors.forename: Andrés
authors.initials: A
authors.lastname: Saralegui
authors.forename: Alfonso
authors.initials: A
authors.lastname: Olivos-García
authors.forename: Carlo
authors.initials: C
authors.lastname: Scapolla
authors.forename: Gianluca
authors.initials: G
authors.lastname: Damonte
authors.forename: Rosana
authors.initials: R
authors.lastname: Sanchez-Lopez
authors.forename: Alejandro
authors.initials: A
authors.lastname: Alagón
authors.forename: Roberto P
authors.initials: RP
authors.lastname: Stock
mesh_terms: D000818:Animals; D006224:Cricetinae; D003546:Cysteine Endopeptidases / Q000378:metabolism; D015536:Down-Regulation; D004748:Entamoeba histolytica / Q000187:drug effects / Q000378:metabolism* / Q000472:pathogenicity; D005434:Flow Cytometry; D007473:Ion Channels / Q000378:metabolism; D008101:Liver Abscess, Amebic / Q000469:parasitology*; D008565:Membrane Proteins / Q000032:analysis / Q000276:immunology / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D020135:Peptide Nucleic Acids / Q000494:pharmacology*; D015800:Protozoan Proteins / Q000032:analysis / Q000276:immunology / Q000378:metabolism*; D011817:Rabbits; D000069816:SEC Translocation Channels; D014774:Virulence; D037521:Virulence Factors / Q000378:metabolism
chemical_list: D007473:Ion Channels; D008565:Membrane Proteins; D020135:Peptide Nucleic Acids; D015800:Protozoan Proteins; D000069816:SEC Translocation Channels; D037521:Virulence Factors; C041670:amoebapore proteins, protozoan; D003546:Cysteine Endopeptidases