title: Acetaldehyde/alcohol dehydrogenase-2 (EhADH2) and clathrin are involved in internalization of human transferrin by Entamoeba histolytica.
abstract: Transferrin (Tf) is a host glycoprotein capable of binding two ferric-iron ions to become holotransferrin (holoTf), which transports iron in to all cells. Entamoeba histolytica is a parasitic protozoan able to use holoTf as a sole iron source in vitro. The mechanism by which this parasite scavenges iron from holoTf is unknown. An E. histolytica holoTf-binding protein (EhTfbp) was purified by using an anti-human transferrin receptor (TfR) monoclonal antibody. EhTfbp was identified by MS/MS analysis and database searches as E. histolytica acetaldehyde/alcohol dehydrogenase-2 (EhADH2), an iron-dependent enzyme. Both EhTfbp and EhADH2 bound holoTf and were recognized by the anti-human TfR antibody, indicating that they correspond to the same protein. It was found that the amoebae internalized holoTf through clathrin-coated pits, suggesting that holoTf endocytosis could be important for the parasite during colonization and invasion of the intestinal mucosa and liver.
authors.affiliation: Programa de Doctorado en Ciencias Biológicas de la Universidad Autónoma Metropolitana, Apdo Postal 23-181, México, DF 04960, Mexico.
authors.forename: Magda
authors.initials: M
authors.lastname: Reyes-López
authors.affiliation: Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Apdo 14-740, México DF 07000, Mexico.
authors.forename: Rosa María
authors.initials: RM
authors.lastname: Bermúdez-Cruz
authors.affiliation: Departamento de Biología, División de Ciencias Naturales y Exactas, Universidad de Guanajuato, Colonia Noria Alta, Guanajuato, Gto, 36000, Mexico.
authors.forename: Eva E
authors.initials: EE
authors.lastname: Avila
authors.affiliation: Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del IPN, Apdo 14-740, México DF 07000, Mexico.
authors.forename: Mireya
authors.initials: M
authors.lastname: de la Garza
mesh_terms: D000426:Alcohol Dehydrogenase / Q000302:isolation & purification / Q000378:metabolism*; D000445:Aldehyde Oxidoreductases / Q000302:isolation & purification / Q000378:metabolism*; D002966:Clathrin / Q000378:metabolism*; D022163:Clathrin-Coated Vesicles / Q000378:metabolism; D004705:Endocytosis; D004748:Entamoeba histolytica / Q000378:metabolism*; D054884:Host-Pathogen Interactions; D006801:Humans; D015800:Protozoan Proteins / Q000302:isolation & purification / Q000378:metabolism; D053719:Tandem Mass Spectrometry; D014168:Transferrin / Q000378:metabolism*
chemical_list: D002966:Clathrin; D015800:Protozoan Proteins; D014168:Transferrin; D000426:Alcohol Dehydrogenase; D000445:Aldehyde Oxidoreductases; C018699:aldehyde dehydrogenase (NAD(P)+)