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)

cAMP and dexamethasone are known to modulate Na+ transport in epithelial cells. We investigated whether dibutyryl cAMP (DBcAMP) and dexamethasone modulate the mRNA expression of two key elements of the Na+ transport system in isolated rat alveolar epithelial cells: alpha-, beta-, and gamma-subunits of the epithelial Na+ channel (ENaC) and the alpha1- and beta1-subunits of Na+-K+-ATPase. The cells were treated for up to 48 h with DBcAMP or dexamethasone to assess their long-term impact on the steady-state level of ENaC and Na+-K+-ATPase mRNA. DBcAMP induced a twofold transient increase of alpha-ENaC and alpha1-Na+-K+-ATPase mRNA that peaked after 8 h of treatment. It also upregulated beta- and gamma-ENaC mRNA but not beta1-Na+-K+-ATPase mRNA. Dexamethasone augmented alpha-ENaC mRNA expression 4.4-fold in cells treated for 24 h and also upregulated beta- and gamma-ENaC mRNA. There was a 1.6-fold increase at 8 h of beta1-Na+-K+-ATPase mRNA but no significant modulation of alpha1-Na+-K+-ATPase mRNA expression. Because DBcAMP and dexamethasone did not increase the stability of alpha-ENaC mRNA, we cloned 3.2 kb of the 5' sequences flanking the mouse alpha-ENaC gene to study the impact of DBcAMP and dexamethasone on alpha-ENaC promoter activity. The promoter was able to drive basal expression of the chloramphenicol acetyltransferase (CAT) reporter gene in A549 cells. Dexamethasone increased the activity of the promoter by a factor of 5.9. To complete the study, the physiological effects of DBcAMP and dexamethasone were investigated by measuring transepithelial current in treated and control cells. DBcAMP and dexamethasone modulated transepithelial current with a time course reminiscent of the profile observed for alpha-ENaC mRNA expression. DBcAMP had a greater impact on transepithelial current (2.5-fold increase at 8 h) than dexamethasone (1.8-fold increase at 24 h). These results suggest that modulation of alpha-ENaC and Na+-K+-ATPase gene expression is one of the mechanisms that regulates Na+ transport in alveolar epithelial cells.
 ...
PMID:Modulation of alpha-ENaC and alpha1-Na+-K+-ATPase by cAMP and dexamethasone in alveolar epithelial cells. 1140 65

SRCAP (SNF2-related CPB activator protein) belongs to the SNF2 family of proteins whose members participate in various aspects of transcriptional regulation, including chromatin remodeling. It was identified by its ability to bind to cAMP-responsive-binding protein (CREB)-binding protein (CBP), and it increases the transactivation function of CBP. The phosphoenolpyruvate carboxykinase (PEPCK) promoter was used as a model system to explore the role of SRCAP in the regulation of transcription mediated by factors that utilize CBP as a coactivator. We show that transcription of a PEPCK chloramphenicol acetyltransferase (CAT) reporter gene activated by protein kinase A (PKA) is enhanced 7-fold by SRCAP. In the absence of PKA this SRCAP-mediated enhancement does not occur, suggesting that SRCAP functions as a coactivator for PKA-activated factors such as CREB. Replacing the PEPCK promoter binding site for CREB with a binding site for Gal4 (DeltaCRE (cAMP-responsive element) Gal4 PEPCK-CAT reporter gene) blocks the ability of SRCAP to activate transcription despite the presence of PKA. Expression of a Gal-CREB chimera restores the ability of PKA to regulate transcription of the DeltaCRE Gal4 PEPCK gene and restored the ability of SRCAP to stimulate PKA-activated transcription. In addition, SRCAP in the presence of PKA enhances the ability of the Gal-CREB chimera to activate transcription of a Gal-CAT reporter gene that contains only binding sites for Gal4. SRCAP binds to CBP amino acids 280-460, a region that is important for CBP to function as a coactivator for CREB. Overexpression of a SRCAP peptide corresponding to this CBP binding domain acts as a dominant negative inhibitor of CREB-mediated transcription. Structure-function studies were done to explore the mechanism(s) by which SRCAP regulates transcription. These studies indicate that the N-terminal region of SRCAP, which contains five of the seven regions that comprise the ATPase domain, is not needed for activation of CREB-mediated transcription. SRCAP apparently has several domains that participate in the activation of transcription.
 ...
PMID:Regulation of cAMP-responsive element-binding protein-mediated transcription by the SNF2/SWI-related protein, SRCAP. 1152 79

Streptococcus mutans F-ATPase, the major component of the acid-adaptive response of the organism, is transcriptionally upregulated at low pH. Fusions of the F-ATPase promoter to chloramphenicol acetyltransferase indicated that pH-dependent expression is still observed with a short promoter that contains a domain conserved between streptococcal ATPase operons.
 ...
PMID:The F-ATPase operon promoter of Streptococcus mutans is transcriptionally regulated in response to external pH. 1557 3

The V1Vo-ATPase from Enterococcus hirae catalyzes ATP hydrolysis coupled with sodium translocation. Mutants with deletions of each of 10 subunits (NtpA, B, C, D, E, F, G, H, I, and K) were constructed by insertion of a chloramphenicol acetyltransferase gene into the corresponding subunit gene in the genome. Measurements of cell growth rates, 22Na+ efflux activities, and ATP hydrolysis activities of the membranes of the deletion mutants indicated that V-ATPase requires nine of the subunits, the exception being the NtpH subunit. The results of Western blotting and V1-ATPase dissociation analysis suggested that the A, B, C, D, E, F, and G subunits constitute the V1 moiety, whereas the V0 moiety comprises the I and K subunits.
 ...
PMID:Deletion analysis of the subunit genes of V-type Na+-ATPase from Enterococcus hirae. 1678 55

Riemerella anatipestifer is a Gram-negative bacterium that can cause disease in a wide range of wild and domesticated birds, especially waterfowl. The presence of an antibiotic-resistance gene in R. anatipestifer has not yet been reported, indicating the need for investigation. In the present study, 40.5% of R. anatipestifer isolates were found to exhibit resistance to chloramphenicol, while 45.9% showed intermediate resistance and 13.5% were susceptible to chloramphenicol, an antibiotic that has been prohibited for use in food animals in Taiwan since 2003. The resistance gene was identified as the cat gene and cloned by library sequencing. The prevalence of the cat gene in Taiwanese R. anatipestifer isolates was 78.4%. The position of the cat gene was then determined within the novel plasmid, designated pRA0511. pRA0511 was sequenced and shown to be 11,435 bp in size with 10 open reading frames (ORFs). Proteins putatively encoded by these 10 ORFs included four drug-resistance-associated proteins. Two proteins designed as chloramphenicol acetyltransferases (CATs) were encoded by two non-adjacent ORFs, and the other two were TetX2 and a multi-drug ABC transporter permease/ATPase. The putative CAT protein had 62.9 to 79.5% homology to a known type B CAT. The pRA0511 plasmid is the first identified drug-resistance plasmid in R. anatipestifer, more specifically associated with chloramphenicol resistance.
 ...
PMID:Prevalence and molecular characterization of chloramphenicol resistance in Riemerella anatipestifer isolated from ducks and geese in Taiwan. 2095 9


<< Previous 1 2