title: Differential expression and characterization of a member of the mucin-associated surface protein family secreted by Trypanosoma cruzi.
abstract: We describe the characterization, purification, expression, and location of a 52-kDa protein secreted during interaction between the metacyclic form of Trypanosoma cruzi and its target host cell. The protein, which we have named MASP52, belongs to the family of mucin-associated surface proteins (MASPs). The highest levels of expression of both the protein and mRNA occur during the metacyclic and bloodstream trypomastigote stages, the forms that infect the vertebrate host cells. The protein is located in the plasma membrane and in the flagellar pockets of the epimastigote, metacyclic, and trypomastigote forms and is secreted into the medium at the point of contact between the parasite and the cell membrane, as well as into the host-cell cytosol during the amastigote stage. IgG antibodies specific against a synthetic peptide corresponding to the catalytic zone of MASP52 significantly reduce the parasite's capacity to infect the host cells. Furthermore, when the protein is adsorbed onto inert particles of bentonite and incubated with a nonphagocytic cell culture, the particles are able to induce endocytosis in the cells, which seems to demonstrate that MASP52 plays a role in a process whereby the trypomastigote forms of the parasite invade the host cell.
authors.affiliation: Instituto de Biotecnología, Grupo de Bioquímica y Parasitología Molecular, Campus de Fuentenueva, Universidad de Granada, 18071 Granada, Spain.
authors.forename: Luis Miguel
authors.initials: LM
authors.lastname: De Pablos
authors.forename: Gloria González
authors.initials: GG
authors.lastname: González
authors.forename: Jennifer
authors.initials: J
authors.lastname: Solano Parada
authors.forename: Víctor
authors.initials: V
authors.lastname: Seco Hidalgo
authors.forename: Isabel María
authors.initials: IM
authors.lastname: Díaz Lozano
authors.forename: María Mercedes
authors.initials: MM
authors.lastname: Gómez Samblás
authors.forename: Teresa
authors.initials: T
authors.lastname: Cruz Bustos
authors.forename: Antonio
authors.initials: A
authors.lastname: Osuna
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002462:Cell Membrane / Q000469:parasitology; D002522:Chlorocebus aethiops; D018507:Gene Expression Regulation, Developmental; D008018:Life Cycle Stages; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009077:Mucins / Q000378:metabolism; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D014349:Trypanosoma cruzi / Q000254:growth & development* / Q000472:pathogenicity; D014709:Vero Cells
chemical_list: D008565:Membrane Proteins; D009077:Mucins; D015800:Protozoan Proteins