Trypanosomes and related protozoan parasites cause a range of diseases man and his livestock (e.g. Chagas disease and sleeping sickness). The blood-dwelling parasite Trypanosoma brucei escapes immune-destruction through antigenic variation, by periodically changing the production of one variant cell surface glycoprotein (VSG) coat to the next. We will study the genetic basis of immune- evasion. The focus will be on transcriptional control of VSG genes and on understanding the importance of expression site, chromosome and nuclear structure for VSG gene activation. We will also study the biological role of expression site associated genes, that are coordinately transcribed with the VSG gene. We are particularly interested in transcription of VSG genes by a novel type of RNA polymerase that is insensitive to the drug alpha- amanitin. We will characterize this RNA polymerase and compare its transcriptional specificity to that of other eukaryotic RNA polymerases. We will test drugs for their capability to interfere with transcription switching of VSG genes. We will survey the importance of transcription of protein-coding genes by alpha- amanitin insensitive RNA polymerases in trypanosomes and related kinetoplastida. These studies are aimed at understanding the biological role of transcription of protein coding get by RNA polymerase II and another as yet unidentified RNA polymerase. A rationale for drug therapy may result. To facilitate the molecular analysis of these protozoan parasites will further develop a DNA transfection system for T.brucei. We will construct vectors that can be used to introduce foreign genes into trypanosomes. The vectors will be engineered to resemble VSG gene expression sites with which chromosomal rearrangements and transcript control of VSG genes will be studied.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI021784-08
Application #
3132140
Study Section
Tropical Medicine and Parasitology Study Section (TMP)
Project Start
1985-07-01
Project End
1994-06-30
Budget Start
1992-07-01
Budget End
1994-06-30
Support Year
8
Fiscal Year
1992
Total Cost
Indirect Cost
Name
Columbia University (N.Y.)
Department
Type
Schools of Medicine
DUNS #
064931884
City
New York
State
NY
Country
United States
Zip Code
10027
Pham, V P; Rothman, P B; Gottesdiener, K M (1997) Binding of trans-acting factors to the double-stranded variant surface glycoprotein (VSG) expression site promoter of Trypanosoma brucei. Mol Biochem Parasitol 89:11-23
Patnaik, P K; Axelrod, N; Van der Ploeg, L H et al. (1996) Artificial linear mini-chromosomes for Trypanosoma brucei. Nucleic Acids Res 24:668-75
Pham, V P; Qi, C C; Gottesdiener, K M (1996) A detailed mutational analysis of the VSG gene expression site promoter. Mol Biochem Parasitol 75:241-54
Qi, C C; Urmenyi, T; Gottesdiener, K M (1996) Analysis of a hybrid PARP/VSG ES promoter in procyclic trypanosomes. Mol Biochem Parasitol 77:147-59
Gottesdiener, K M (1994) A new VSG expression site-associated gene (ESAG) in the promoter region of Trypanosoma brucei encodes a protein with 10 potential transmembrane domains. Mol Biochem Parasitol 63:143-51
Lee, M G; Russell, D G; D'Alesandro, P A et al. (1994) Identification of membrane-associated proteins in Trypanosoma brucei encoding an internal, EARLRAEE amino acid repeat. J Biol Chem 269:8408-15
Brown, S D; Van der Ploeg, L H (1994) Single-stranded DNA-protein binding in the procyclic acidic repetitive protein (PARP) promoter of Trypanosoma brucei. Mol Biochem Parasitol 65:109-22
Carruthers, V B; van der Ploeg, L H; Cross, G A (1993) DNA-mediated transformation of bloodstream-form Trypanosoma brucei. Nucleic Acids Res 21:2537-8
Chung, H M; Lee, M G; Dietrich, P et al. (1993) Disruption of largest subunit RNA polymerase II genes in Trypanosoma brucei. Mol Cell Biol 13:3734-43
Van der Ploeg, L H; Gottesdiener, K; Lee, M G (1992) Antigenic variation in African trypanosomes. Trends Genet 8:452-7

Showing the most recent 10 out of 35 publications