A major surface glycoprotein of trypanosoma brucei is expressed transiently during development and can be regulated post-transcriptionally by glycerol or hypoxia.
Genes Dev
; 14(5): 615-26, 2000 Mar 01.
Article
em En
| MEDLINE
| ID: mdl-10716949
ABSTRACT
Differentiation is a means by which unicellular parasites adapt to different environments. In some cases, the developmental program may be modulated by interactions with the host, but the mechanisms are largely unknown. Trypanosoma brucei is transmitted between mammals by tsetse flies. The development of the procyclic form in the tsetse midgut is marked by the synthesis of a new glycoprotein coat, composed of EP and GPEET procyclins, that is important for survival. Here we demonstrate that the composition of the coat changes in response to extracellular signals in vitro and during development in vivo. EP and GPEET are coinduced when differentiation is initiated. Subsequently, EP expression is maintained, whereas GPEET is repressed after 7-9 days. The timepoint at which GPEET is repressed coincides with the appearance of parasites in a new compartment of the fly midgut. In culture, down-regulation of GPEET can be prevented by exogenous glycerol or accelerated by hypoxia. Regulation is post-transcriptional, and is conferred by the GPEET 3' untranslated region. The same sequence also regulates expression of a reporter gene in the fly. The finding that GPEET is expressed during a defined window during the establishment of infection suggests that it has a specific function in host-parasite interactions rather than a generalized role in shielding underlying membrane molecules.
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Base de dados:
MEDLINE
Assunto principal:
Trypanosoma brucei brucei
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Glicoproteínas de Membrana
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Regulação da Expressão Gênica no Desenvolvimento
Idioma:
En
Ano de publicação:
2000
Tipo de documento:
Article