ApiLoc - A database of published protein sub-cellular localisation in Apicomplexa

version 3 (curated until May 28, 2011)

Differential subcellular localization of members of the Toxoplasma gondii small heat shock protein family.

de Miguel, N., Echeverria, P. C., Angel, S. O. (2005 Dec, Eukaryot Cell)

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.

PubMed: 16339717, full text

Localisation information

TGME49_032940 (Hsp20) small heat shock protein 20

Experimental localisation: apical during intracellular tachyzoite
  • Species: Toxoplasma gondii
  • Quote inferring localisation: "In tachyzoite and bradyzoite stages, Hsp20 antiserum gave a crescent-shaped pattern at the apical end of the cell, labeling mostly a small area at the conoid of the parasite (Fig. 4B and E). Moreover, in some bradyzoites a membrane-associated labeling was also observed (Fig. 4H)."
  • Microscopy type: Light
  • Microscopy method: antibody directly to protein
  • Strain: PK
  • Gene model mapping comments: blast from AY644771, annotation matches
  • Localisation record: apical during intracellular tachyzoite

TGME49_032940 (Hsp20) small heat shock protein 20

Experimental localisation: parasite plasma membrane during bradyzoite, apical during bradyzoite
  • Species: Toxoplasma gondii
  • Quote inferring localisation: "Note the targeting of Hsp20 at the apical region in the merged labeled image (merged) in tachyzoites (C) and bradyzoites (F) and the membrane-associated labeling in bradyzoite stages (I)."
  • Microscopy type: Light
  • Microscopy method: antibody directly to protein
  • Strain: ME49
  • Gene model mapping comments: inferred from another publication
  • Localisation record: membrane and apical during bradyzoite

TGME49_086720 (Hsp28) heat shock protein 28

Experimental localisation: mitochondrion during tachyzoite
  • Species: Toxoplasma gondii
  • Quote inferring localisation: "The localization of Hsp28 displayed a staining pattern inside the mitochondrion of the parasite that was similar to that observed with the MitoTraker marker"
  • Microscopy type: Light
  • Microscopy method: antibody directly to protein
  • Strain: PK
  • Gene model mapping comments: blast from AY650281, annotation matches
  • Localisation record: mitochondrion during tachyzoite

TGME49_086720 (Hsp28) heat shock protein 28

Experimental localisation: not bradyzoite
  • Species: Toxoplasma gondii
  • Quote inferring localisation: "Colocalization of Hsp28 and mitotracker staining is observed in the merged image in the tachyzoite stage. Note the lack of reactivity of rabbit polyclonal anti-Hsp28 in the bradyzoite stage."
  • Microscopy type: Light
  • Microscopy method: antibody directly to protein
  • Strain: ME49
  • Gene model mapping comments: inferred from another publication
  • Localisation record: not during bradyzoite

TGME49_089600 (Hsp29) Hsp20/alpha crystallin domain-containing protein

Experimental localisation: parasite plasma membrane during tachyzoite
  • Species: Toxoplasma gondii
  • Quote inferring localisation: "Double immunofluorescence assays employing anti-Hsp29 antibodies and a monoclonal antibody directed against anti-P30, a surface protein, indicated a membrane-associated localization of this protein in tachyzoite and bradyzoite stages"
  • Microscopy type: Light
  • Microscopy method: antibody directly to protein
  • Strain: PK
  • Gene model mapping comments: blast from AY721614, annotation does not match
  • Localisation record: membrane during tachyzoite

TGME49_089600 (Hsp29) Hsp20/alpha crystallin domain-containing protein

Experimental localisation: parasite plasma membrane during bradyzoite
  • Species: Toxoplasma gondii
  • Quote inferring localisation: "Our data provide clear evidence that Hsp29 protein is associated to the membrane of the parasite, in the tachyzoite as well as in the bradyzoite stage."
  • Microscopy type: Light
  • Microscopy method: antibody directly to protein
  • Strain: ME49
  • Gene model mapping comments: inferred from another publication
  • Localisation record: membrane during bradyzoite

TGME49_112600 (Hsp21) small heat shock protein 21

Experimental localisation: cytosol during tachyzoite, not nucleus during tachyzoite
  • Species: Toxoplasma gondii
  • Quote inferring localisation: "Using the anti-Hsp21 antibody, the signal in tachyzoite and bradyzoite stages appeared throughout the cytosol of parasites but not in the nucleus"
  • Microscopy type: Light
  • Microscopy method: antibody directly to protein
  • Strain: PK
  • Gene model mapping comments: blast from AY756061, annotation matches
  • Localisation record: cytosol and not nucleus during tachyzoite

TGME49_112600 (Hsp21) small heat shock protein 21

Experimental localisation: cytosol during bradyzoite, not nucleus during bradyzoite
  • Species: Toxoplasma gondii
  • Quote inferring localisation: "Indirect immunofluorescence localization of Hsp21. Tachyzoites (upper panel) and bradyzoites (lower panel) were stained with rabbit polyclonal antibody anti-Hsp21 and mouse polyclonal antibody anti-H2A.Z histone to evidence the cytosolic localization of Hsp21"
  • Microscopy type: Light
  • Microscopy method: antibody directly to protein
  • Strain: ME49
  • Gene model mapping comments: inferred from another publication
  • Localisation record: cytosol and not nucleus during bradyzoite