IAI Accepts, published online ahead of print on 19 October 2009

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Google Scholar Articles by Lander, N. Articles by Ramírez, J. L. PubMed PubMed Citation Articles by Lander, N. Articles by Ramírez, J. L.

 Previous Article  |  Next Article 

Infect. Immun. doi:10.1128/IAI.00780-09
Copyright (c) 2009, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

Localization and developmental regulation of a dispersed gene family-1 (DGF-1) protein in Trypanosoma cruzi

Noelia Lander, Carolina Bernal, Nardy Diez, Néstor Añez, Roberto Docampo, and José Luis Ramírez^*

Centro de Biotecnología, Fundación Instituto de Estudios Avanzados (IDEA), Caracas, Venezuela; Department of Cellular Biology and Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA; Facultad de Ciencias, Centro de Investigaciones Parasitológicas "J.F. Torrealba", Universidad de los Andes, Mérida, Venezuela

^* To whom correspondence should be addressed. Email: ramjoseluis{at}gmail.com.

The dispersed gene family-1 (DGF-1) is the fifth largest gene family in the T. cruzi genome, with over 500 members (11). Many of the predicted DGF-1 protein products have several transmembrane domains, and N-glycosylation and phosphorylation sites, and were thought to localize in the plasma membrane. Here we report that affinity-purified antibodies against a region of one of these proteins (DGF-1.2) localized it intracellularly in different stages of the parasite. DGF1.2 is more abundant in the amastigote stage than in trypomastigotes and epimastigotes, as detected by immunofluorescence and western blot analyses. The protein changed localization during intracellular or extracellular differentiation from trypomastigote to amastigote stages, where it finally localized to small bodies in close contact with the inner side of the amastigote plasma membrane. DGF-1.2 did not co-localize with markers of other subcellular organelles such as acidocalcisomes, glycosomes, reservosomes, lipid droplets or endocytic vesicles. During extracellular differentiation the protein was detected in the culture medium from 0 to 22 hours, peaking at the 14 h. The presence of DGF-1.2 in the differentiation culture medium was confirmed by mass spectrometry analysis. Finally, when epimastigotes were subjected to starvation, there was a decrease in the labeling of the cells, and in western blots the appearance of bands of smaller molecular mass suggesting its cleavage. These results represent the first report of direct immunodetection and developmental expression and secretion of a DGF-1 protein.