For the first time a transient transfection system was developed for Giardia lamblia using flanking regions of the glutamate dehydrogenase gene and the luciferase reporter gene. This will enable study of transcription of genes such as those that are induced during encystment, genes which undergo antigenic variation and constitutively expressed genes. Cwp2, a second protein constituent of the Giardia lamblia cyst wall was identified and sequenced. Monoclonal antibodies were made to encystment vesicles and cyst walls and were used to identify proteins important in vesicular transport and constituents of the cyst wall. Entamoeba histolytica contains genes encoding proteins normally associated with the mitochondrion, an organelle this organism appears to lack. Sequence and phylogenetic analysis of two such Entamoeba genes has been performed and confirms the specific relatedness. This has major implications for our understanding of the unique biochemistry of this parasite. The same genes have been sought in other parasites thought to lack mitochondria. Analysis of a homologous gene isolated from Trichomonas indicates a similar evolutionary history and implies descent from a mitochondrion bearing ancestor.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Intramural Research (Z01)
Project #
1Z01AI000350-13
Application #
5200450
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
13
Fiscal Year
1995
Total Cost
Indirect Cost
City
State
Country
United States
Zip Code
Worgall, Tilla S; Davis-Hayman, Sara R; Magana, Marissa M et al. (2004) Sterol and fatty acid regulatory pathways in a Giardia lamblia-derived promoter: evidence for SREBP as an ancient transcription factor. J Lipid Res 45:981-8
Davis-Hayman, Sara R; Hayman, J Russell; Nash, Theodore E (2003) Encystation-specific regulation of the cyst wall protein 2 gene in Giardia lamblia by multiple cis-acting elements. Int J Parasitol 33:1005-12
Davis-Hayman, Sara R; Nash, Theodore E (2002) Genetic manipulation of Giardia lamblia. Mol Biochem Parasitol 122:1-7
Nash, Theodore E (2002) Surface antigenic variation in Giardia lamblia. Mol Microbiol 45:585-90
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Nash, T E; Lujan, H T; Mowatt, M R et al. (2001) Variant-specific surface protein switching in Giardia lamblia. Infect Immun 69:1922-3
Elmendorf, H G; Singer, S M; Nash, T E (2001) The abundance of sterile transcripts in Giardia lamblia. Nucleic Acids Res 29:4674-83
Singer, S M; Elmendorf, H G; Conrad, J T et al. (2001) Biological selection of variant-specific surface proteins in Giardia lamblia. J Infect Dis 183:119-24
Elmendorf, H G; Singer, S M; Pierce, J et al. (2001) Initiator and upstream elements in the alpha2-tubulin promoter of Giardia lamblia. Mol Biochem Parasitol 113:157-69