TY - JOUR

T1 - The PARP promoter of Trypanosoma brucei is developmentally regulated in a chromosomal context

AU - Biebinger, S

AU - Rettenmaier, S

AU - Flaspohler, J

AU - Hartmann, C

AU - Pena Diaz, Javier

AU - Wirtz, L E

AU - Hotz, H R

AU - Barry, J D

AU - Clayton, C

PY - 1996/4/1

Y1 - 1996/4/1

N2 - African trypanosomes are extracellular protozoan parasites that are transmitted from one mammalian host to the next by tsetse flies. Bloodstream forms express variant surface glycoprotein (VSG); the tsetse fly (procyclic) forms express instead the procyclic acidic repetitive protein (PARP). PARP mRNA is abundant in procyclic forms and almost undetectable in blood-stream forms. Post-transcriptional mechanisms are mainly responsible for PARP mRNA regulation but results of nuclear run-on experiments suggested that transcription might also be regulated. We measured the activity of genomically-integrated PARP, VSG and rRNA promoters in permanently-transformed blood-stream and procyclic form trypanosomes, using reporter gene constructs that showed no post-transcriptional regulation. When the constructs were integrated in the rRNA non-transcribed spacer, the ribosomal RNA and VSG promoters were not developmentally regulated, but integration at the PARP locus reduced rRNA promoter activity in bloodstream forms. PARP promoter activity was 5-fold down-regulated in bloodstream forms when integrated at either site. Regulation was probably at the level of transcriptional initiation, but elongation through plasmid vector sequences was also reduced.

AB - African trypanosomes are extracellular protozoan parasites that are transmitted from one mammalian host to the next by tsetse flies. Bloodstream forms express variant surface glycoprotein (VSG); the tsetse fly (procyclic) forms express instead the procyclic acidic repetitive protein (PARP). PARP mRNA is abundant in procyclic forms and almost undetectable in blood-stream forms. Post-transcriptional mechanisms are mainly responsible for PARP mRNA regulation but results of nuclear run-on experiments suggested that transcription might also be regulated. We measured the activity of genomically-integrated PARP, VSG and rRNA promoters in permanently-transformed blood-stream and procyclic form trypanosomes, using reporter gene constructs that showed no post-transcriptional regulation. When the constructs were integrated in the rRNA non-transcribed spacer, the ribosomal RNA and VSG promoters were not developmentally regulated, but integration at the PARP locus reduced rRNA promoter activity in bloodstream forms. PARP promoter activity was 5-fold down-regulated in bloodstream forms when integrated at either site. Regulation was probably at the level of transcriptional initiation, but elongation through plasmid vector sequences was also reduced.

KW - Animals

KW - Base Sequence

KW - DNA Primers

KW - Gene Expression Regulation, Developmental

KW - Membrane Glycoproteins

KW - Molecular Sequence Data

KW - Promoter Regions, Genetic

KW - Protozoan Proteins

KW - RNA, Ribosomal

KW - Transcription, Genetic

KW - Trypanosoma brucei brucei

KW - Tubulin

M3 - Journal article

C2 - 8614620

VL - 24

SP - 1202

EP - 1211

JO - Nucleic Acids Research

JF - Nucleic Acids Research

SN - 0305-1048

IS - 7

ER -