Parasite-encoded Hsp40 proteins define novel mobile structures in the cytosol of the P. falciparum-infected erythrocyte.
Cell Microbiol
; 12(10): 1398-420, 2010 Oct.
Article
em En
| MEDLINE
| ID: mdl-20482550
ABSTRACT
Plasmodium falciparum is predicted to transport over 300 proteins to the cytosol of its chosen host cell, the mature human erythrocyte, including 19 members of the Hsp40 family. Here, we have generated transfectant lines expressing GFP- or HA-Strep-tagged versions of these proteins, and used these to investigate both localization and other properties of these Hsp40 co-chaperones. These fusion proteins labelled punctate structures within the infected erythrocyte, initially suggestive of a Maurer's clefts localization. Further experiments demonstrated that these structures were distinct from the Maurer's clefts in protein composition. Transmission electron microscopy verifies a non-cleft localization for HA-Strep-tagged versions of these proteins. We were not able to label these structures with BODIPY-ceramide, suggesting a lower size and/or different lipid composition compared with the Maurer's clefts. Solubility studies revealed that the Hsp40-GFP fusion proteins appear to be tightly associated with membranes, but could be released from the bilayer under conditions affecting membrane cholesterol content or organization, suggesting interaction with a binding partner localized to cholesterol-rich domains. These novel structures are highly mobile in the infected erythrocyte, but based on velocity calculations, can be distinguished from the 'highly mobile vesicles' previously described. Our study identifies a further extra-parasitic structure in the P. falciparum-infected erythrocyte, which we name 'J-dots' (as their defining characteristic so far is the content of J-proteins). We suggest that these J-dots are involved in trafficking of parasite-encoded proteins through the cytosol of the infected erythrocyte.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Plasmodium falciparum
/
Proteínas de Protozoários
/
Citosol
/
Eritrócitos
/
Proteínas de Choque Térmico HSP40
/
Interações Hospedeiro-Parasita
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
Cell Microbiol
Assunto da revista:
MICROBIOLOGIA
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Alemanha