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

Creatine kinase (EC 2.7.3.2) (CK) isoenzymes are crucial to energy metabolism, particularly in tissues with high energy requirements. Nuclear genes encode four known CK subunits: cytoplasmic muscle, cytoplasmic brain, ubiquitous mitochondrial (uMtCK), and sarcomeric mitochondrial (sMtCK). Herein, we report the isolation and complete structural characterization of the human sMtCK gene. It contains 11 exons and encompasses more than 37 kilobase pairs (kb). The sites of exon localization in the sMtCK-coding region and their precise sizes are identical with the human uMtCK gene. The translation start codon is in the third exon and lies 17 kb from the transcription start site. The human sMtCK gene is located on chromosome 5. Sequence analysis of the sMtCK genomic upstream sequences reveals a typical TATAA box within the 80 base pairs (bp) that, by transfection experiments, are sufficient to promote expression of chimeric plasmids with the chloramphenicol acetyltransferase reporter. Cis-acting sequences in a fragment containing 3360 bp of upstream sequence, the first exon, and 750 bp of the first intron are sufficient to mediate tissue-specific expression. However, these sequences only partially regulate induction of sMtCK expression in differentiating mouse myoblasts. MEF1/MYOD and MEF2 sequence motifs present in the sMtCK gene are not sufficient to regulate differentiation-specific expression. The sMtCK gene contains sequences homologous to several motifs that are shared among some nuclear genes encoding mitochondrial proteins and that may be essential for the coordinated activation of these genes during mitochondrial biogenesis.
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PMID:Regulatory element analysis and structural characterization of the human sarcomeric mitochondrial creatine kinase gene. 191 43

The brain isozyme of creatine kinase (CKB) is a major component of the estrogen-induced proteins in the rat uterus. Hormonal specificity of this response was studied in cotransfection assays using the rat CKB promoter linked to the bacterial chloramphenicol acetyltransferase gene. Response was specific for estrogen as 17 beta-estradiol in the presence of estrogen receptor dramatically stimulated the CKB promoter. This induction was completely blocked by the estrogen antagonist ICI 164,384. Nuclear receptors for progesterone, androgen, glucocorticoid and vitamin D did not significantly activate the CKB promoter in the presence of their respective ligands. Creatine kinase (CK) activity was analyzed in decidualized mouse uterus to assess estrogenic activity in vivo. Upon oil stimulation, uterine horns of day 4 pseudopregnant mice underwent a dramatic outgrowth in response to endogenous progesterone. This response was accompanied by a significant decrease in CK activity from a control value of 1.44 +/- 0.25 to 0.38 +/- 0.08 IU/mg protein (P < 0.001), indicating that the action of estrogen was suppressed. Treatment of females one day prior to oil-stimulation with progesterone receptor antagonists, RU486 (Mifepristone) or ZK299 (Onapristone), or with a monoclonal antibody to progesterone (DB3), abolished decidualization, and also restored the CK activity to the control value. These results suggest that CK can be used as a specific cellular marker to detect unopposed estrogen action in the mouse uterus associated with progesterone withdrawal or receptor blockade.
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PMID:Creatine kinase activity as an indicator of unopposed estrogen action in the mouse uterus associated with anti-progesterone treatment. 803 8