Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:2.3.1.28 (
chloramphenicol acetyltransferase
)
5,100
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
BAG1
is a small heat-shock protein of Toxoplasma gondii that is specifically expressed in the cyst-forming bradyzoite stage of the parasite. Upregulation of
BAG1
mRNA occurs early during the differentiation pathway from tachyzoites to bradyzoites. In order define genomic elements involved in bradyzoite-specific gene regulation,
chloramphenicol acetyltransferase
(
CAT
)-reporter gene studies were performed with 5' flanking sequences of the
BAG1
gene. Tachyzoites, transiently transfected with the
BAG1
/cat construct, exhibited very low
CAT
activity (200 fold less than in parasites transfected with a tubulin promoter/cat construct). After induction of bradyzoite differentiation by alkaline pH shift, however,
CAT
activity increased 50 fold, demonstrating bradyzoite-specific expression of the
CAT
reporter gene under control of 5' flanking sequences of
BAG1
. Stage-specific regulation of
BAG1
/
CAT
was independent of the 3'-flanking region, since constructs containing 3'-flanking sequences of the tachyzoite-specific SAG1 gene showed identical regulation to those containing the
BAG1
3'-flanking region. The kinetics of
BAG1
/
CAT
induction in stably transfected parasites is similar to the kinetics of endogenous
BAG1
expression: increased
CAT
activity was first detected on day 3 after alkaline pH shift (20 fold) and was dramatically upregulated 250 fold on day 4. A series of deletions in the
BAG1
5'-flanking sequences demonstrated that a 324 nucleotide (nt) fragment, starting 60 nt upstream of the
BAG1
transcription start, is sufficient to confer stage-specific regulation on the
CAT
reporter. These deletion analyses demonstrate that bradyzoite-specific expression of a heterologeous reporter gene requires only minimal genomic sequences.
...
PMID:Bradyzoite-specific gene expression in Toxoplasma gondii requires minimal genomic elements. 910 51
