title: Differential subcellular localization of members of the Toxoplasma gondii small heat shock protein family.
abstract: The results of this study describe the identification and characterization of the Toxoplasma gondii alpha-crystallin/small heat shock protein (sHsp) family. By database (www.toxodb.org) search, five parasite sHsps (Hsp20, Hsp21, Hsp28, Hsp29, and the previously characterized Hsp30/Bag1) were identified. As expected, they share the homologous alpha-crystallin domain, which is the key characteristic of sHsps. However, the N-terminal segment of each protein contains unique characteristics in size and sequence. Most T. gondii sHsps are constitutively expressed in tachyzoites and fully differentiated bradyzoites, with the exception of Hsp30/Bag1. Interestingly, by subcellular localization we observed that T. gondii sHsps are located in different compartments. Hsp20 is located at the apical end of the cell, Hsp28 is located inside the mitochondrion, Hsp29 showed a membrane-associated labeling, and Hsp21 appeared throughout the cytosol of the parasites. These particular differences in the immunostaining patterns suggest that their targets and functions might be different.
authors.affiliation: Laboratorio de Parasitología Molecular, IIB-INTECH, Camino Circunvalación Laguna Km6, C.C 164, 7130 Chascomús, Prov. Buenos Aires, Argentina.
authors.forename: N
authors.initials: N
authors.lastname: de Miguel
authors.forename: P C
authors.initials: PC
authors.lastname: Echeverria
authors.forename: S O
authors.initials: SO
authors.lastname: Angel
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D000913:Antibodies, Protozoan / Q000096:biosynthesis; D002451:Cell Compartmentation; D002460:Cell Line; D003600:Cytosol / Q000378:metabolism; D016054:DNA, Protozoan; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics; D020224:Expressed Sequence Tags; D019084:Fluorescent Antibody Technique, Indirect; D015870:Gene Expression; D017125:Genes, Protozoan; D050886:HSP20 Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D050890:HSP30 Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008018:Life Cycle Stages; D051379:Mice; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D015800:Protozoan Proteins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014122:Toxoplasma / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D014123:Toxoplasmosis / Q000469:parasitology; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics; D038201:alpha-Crystallins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D000913:Antibodies, Protozoan; C091732:BCL2-associated athanogene 1 protein; D016054:DNA, Protozoan; D004268:DNA-Binding Proteins; D050886:HSP20 Heat-Shock Proteins; D050890:HSP30 Heat-Shock Proteins; D015800:Protozoan Proteins; D011994:Recombinant Proteins; D014157:Transcription Factors; D038201:alpha-Crystallins