Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.3.1.28 (chloramphenicol acetyltransferase)
 5,100 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The system coordinating expressions of nuclear coded mitochondrial proteins was investigated by examination of the 5'-flanking region of the human mitochondrial ATP synthase beta-subunit gene. The promoter activity was measured by a transient expression of a chloramphenicol acetyltransferase (CAT) gene connected with various 5'-deletion mutants of the 5'-flanking region. In this experiment, at least two regions enhanced this promoter activity and at least one region repressed it. In one of the enhancing regions, a consensus sequence was found for the genes of other mitochondrial proteins such as those for cytochrome c1 (Suzuki, H., Hosokawa, Y., Nishikimi, M., and Ozawa, T. (1989) J. Biol. Chem. 264, 1368-1374) and the pyruvate dehydrogenase alpha-subunit (Maragos, C., Hutchison, W. M., Hayasaka, K., Brown, G. K., and Dahl, H.-H. M. (1989) J. Biol. Chem. 264, 12294-12298; Ohta, S., Endo, H., Matsuda, K., and Kagawa, Y. (1989) Ann. N. Y. Acad. Sci. 573, 458-460). The characteristics of this enhancing element were examined by introducing a synthetic oligonucleotide element into the CAT plasmid with a deleted enhancing element. The resulting plasmid showed full recovery of promoter activity, and this activity was independent of the orientation or location of the insert. Therefore, this is an enhancer that may be common to the nuclear genes of some mitochondrial proteins involved in energy transduction.
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PMID:Novel regulatory enhancer in the nuclear gene of the human mitochondrial ATP synthase beta-subunit. 218 18

Three positive transcriptional control regions have been identified in the promoter of the human heart-skeletal muscle adenine nucleotide translocator gene (ANT1). By transfecting promoter-chloramphenicol acetyltransferase fusion constructs into C2C12 myogenic cells, each positive region was found to increase transcription 2-3-fold. The first region spans from -123 to -674 base pairs (bp), the second from -2.6 to -3.1 kilobases, and the third from -3.1 to -8.8 kilobases. Linker-scanning mutants generated using the polymerase chain reaction and modified oligonucleotides have identified the OXBOX (5'-GGCTCTAAAGAGG) as the positive element within the -123 to -674-bp region. This element enhances transcription in muscle cells but not in HeLa cells, suggesting that it is muscle-specific. Gel retardation experiments have revealed a factor from C2C12 cells which specifically binds to a 40-bp piece of the ANT1 promoter containing the OXBOX. Since the OXBOX is also found in the promoter of the human ATP synthase beta subunit gene, it is the first tissue-specific element identified which could coordinately regulate mitochondrial oxidative phosphorylation genes.
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PMID:OXBOX, a positive transcriptional element of the heart-skeletal muscle ADP/ATP translocator gene. 224 5

Nine different proteins were imported into isolated pea chloroplasts in vitro. For seven of these [the large and small subunits of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), beta-subunit of ATP synthase, glutamine synthetase, the light-harvesting chlorophyll a/b binding protein, chloramphenicol acetyltransferase, and pre-beta-lactamase], a fraction was found to migrate as a stable high-molecular-weight complex during nondenaturing gel electrophoresis. This complex contained the mature forms of the imported proteins and the groEL-related chloroplast chaperonin 60 (previously known as Rubisco subunit binding protein). Thus, the stable association of imported proteins with this molecular chaperone is widespread and not necessarily restricted to Rubisco subunits or to chloroplast proteins. With two of the imported proteins (ferredoxin and superoxide dismutase), such complexes were not observed. It seems likely that, in addition to its proposed role in assembly of Rubisco, the chloroplast chaperonin 60 is involved in the assembly or folding of a wide range of proteins in chloroplasts.
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PMID:Several proteins imported into chloroplasts form stable complexes with the GroEL-related chloroplast molecular chaperone. 257 24

Most mitochondrial proteins are encoded by nuclear genes and are synthesized as precursors containing a presequence at the N terminus. In yeast and in mammalian cells, the function of the presequence in mitochondrial targeting has been revealed by chimaeric gene studies. Fusion of a mitochondrial presequence to a foreign protein coding sequence enables the protein to be imported into mitochondria in vitro as well as in vivo. Whether plant mitochondrial presequences function in the same way has been unknown. We have previously isolated and characterized a nuclear gene (atp2-1) from Nicotiana plumbaginifolia that encodes the beta-subunit of the mitochondrial ATP synthase. We have constructed a chimaeric gene comprising a putative atp2-1 presequence fused to the bacterial chloramphenicol acetyltransferase (CAT) coding sequence and introduced it into the tobacco genome. We report here that a segment of 90 amino acids of the N terminus of the beta-subunit precursor is sufficient for the specific targeting of the CAT protein to mitochondria in transgenic plants. Our results demonstrate a high specificity for organelle targeting in plant cells.
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PMID:Targeting of bacterial chloramphenicol acetyltransferase to mitochondria in transgenic plants. 347 28

Three positive (PR1-3) and one negative (NR1) transcriptional control domain have been tentatively mapped in the promoter of the human F0F1-ATP synthase beta subunit gene (ATPsyn beta) in the context of expression in myogenic cells. Lipofection of promoter-chloramphenicol acetyltransferase fusion constructs into C2C12 myogenic cells revealed that two of the three positive domains (PR1 and PR2) function in both myoblasts and myotubes, whereas the third positive domain (PR3) and the sole negative domain (NR1) seem to function only in myotubes. PR1 contains a cluster of four CCAAT cis-elements, PR2 is a small 44-base pair region containing an SP1-like motif, and PR3 is a region previously shown to be recognized by both OXBOX- and REBOX-binding factors. By site-directed polymerase chain reaction linker mutations, the activity of the OXBOX/REBOX cis-element in myoblasts is shown to be masked by flanking sequences in PR3. The negative domain, NR1, is located between 300 and 1,000 base pairs upstream from the OXBOX/REBOX elements in a region containing multiple Alu repeats. Mobility gel shift analysis of DNA-protein complexes using competitor DNAs verified the involvement of both OXBOX- and REBOX-binding factors in PR3. Similar experiments show SP1-specific binding at PR2. These data with observations of OXBOX and REBOX-specific binding of an OXBOX/REBOX-like region within the conserved sequence block C of the human mitochondrial DNA D-loop sequence are consistent with the idea that OXBOX- and REBOX DNA-binding factors coordinate the expression of mitochondrial energy genes in highly oxidative tissues by working with well characterized general transcription factors such as SP1 and CCAAT DNA-binding proteins, which exist in the nucleus, and MTF, which exists in the mitochondrion.
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PMID:OXBOX and REBOX, overlapping promoter elements of the mitochondrial F0F1-ATP synthase beta subunit gene. OXBOX/REBOX in the ATPsyn beta promoter. 813 72