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)
To understand the mechanism of p56lck protein downregulation observed in human T cells infected by human T-cell leukemia virus type 1 (HTLV-1), we have investigated the ability of the 3' end of the HTLV-1 genome as well as that of the tax and rex genes to modulate p56lck protein expression and p56lck mRNA synthesis. By using Jurkat T cells stably transfected with constructs that expressed either the 3' end of the HTLV-1 genome (JK C11-pMTEX), the tax gene (JK52-Tax) or the rex gene (JK9-
Rex
), we found that the expression of p40tax (Tax) was sufficient to modulate p56lck protein expression. Similarly, we found that the expression of the mRNA which encoded p56lck was repressed in Jurkat T cells which expressed Tax. This downregulation was shown to be proportional to the amount of tax mRNA found in the transfected cells, as evidenced by experiments that used cells (JPX-9) stably transfected with a tax gene driven by a cadmium-inducible promoter. Furthermore, cadmium induction of Tax in JPX-9 cells transiently transfected with a construct containing the
chloramphenicol acetyltransferase
(
CAT
) gene under control of the lck distal promoter (lck DP-
CAT
) resulted in the downregulation of
CAT
gene expression. In contrast, cadmium induction of Tax in JPX-9 cells transiently transfected with a
CAT
construct driven by a lck DP with a deletion extending from position -259 to -253 (a sequence corresponding to a putative E-Box) did not modulate
CAT
gene expression, suggesting that the effect of Tax on p56lck is mediated through an E-Box binding protein.
...
PMID:Transrepression of lck gene expression by human T-cell leukemia virus type 1-encoded p40tax. 903 29
