scholarly journals The bacterial enhancer-binding protein NTRC is a molecular machine: ATP hydrolysis is coupled to transcriptional activation.

1995 ◽  
Vol 9 (16) ◽  
pp. 2042-2052 ◽  
Author(s):  
A Wedel ◽  
S Kustu
Keyword(s):  
Transcriptional Activation ◽  
Atp Hydrolysis ◽  
Binding Protein ◽  
Molecular Machine ◽  
Enhancer Binding Protein

The Bacterial Enhancer-binding Protein NtrC as a Molecular Machine

1998 ◽  
Vol 63 (0) ◽  
pp. 157-166 ◽  
Author(s):  
I. ROMBEL ◽  
A. NORTH ◽  
I. HWANG ◽  
C. WYMAN ◽  
S. KUSTU
Keyword(s):  
Binding Protein ◽  
Molecular Machine ◽  
Enhancer Binding Protein

A novel myeloid-restricted zebrafish CCAAT/enhancer-binding protein with a potent transcriptional activation domain

Blood ◽  
2001 ◽  
Vol 97 (9) ◽  
pp. 2611-2617 ◽  
Author(s):  
Susan E. Lyons ◽  
Bixiong C. Shue ◽  
Andrew C. Oates ◽  
Leonard I. Zon ◽  
P. Paul Liu
Keyword(s):  
Dna Binding ◽  
Transcriptional Activation ◽  
Binding Protein ◽  
Myeloid Cells ◽  
Mobility Shift ◽  
Nih3t3 Cells ◽  
Amino Terminal ◽  
Enhancer Binding Protein ◽  
Bzip Domain ◽  
Ccaat Enhancer Binding Protein

Abstract The CCAAT/enhancer-binding protein (C/EBP) family consists of transcription factors essential for hematopoiesis. The defining feature of the C/EBPs is a highly conserved carboxy-terminal bZIP domain that is necessary and sufficient for dimerization and DNA binding, whereas their amino-terminal domains are unique. This study reports a novelc/ebp gene (c/ebp1) from zebrafish that encodes a protein homologous to mammalian C/EBPs within the bZIP domain, but with an amino terminus lacking homology to any C/EBP or to any known sequence. In zebrafish embryos, c/ebp1 expression was initially observed in cells within the yolk sac circulation valley at approximately the 16-to 18-somite stage, and at 24 hours postfertilization (hpf), also in circulating cells. Mostc/ebp1+cells also expressed a known early macrophage marker, leukocyte-specific plastin (l-plastin). Expression of both markers was lost in cloche, a mutant affecting hematopoiesis at the level of the hemangioblast. Expression of both markers was retained in m683 andspadetail, mutants affecting erythropoiesis, but not myelopoiesis. Further, c/ebp1 expression was lost in a mutant with defective myelopoiesis, but intact erythropoiesis. These data suggest that c/ebp1 is expressed exclusively in myeloid cells. In electrophoretic mobility shift assays, c/ebp1 was able to bind a C/EBP consensus DNA site. Further, a chimeric protein containing the amino-terminal domain of c/ebp1 fused to the DNA-binding domain of GAL4 induced a GAL4 reporter 4000-fold in NIH3T3 cells. These results suggest that c/ebp1 is a novel member of the C/EBP family that may function as a potent transcriptional activator in myeloid cells.

scholarly journals Endogenous CCAAT/Enhancer Binding Protein β and p300 Are Both Regulated by Growth Hormone to Mediate Transcriptional Activation

2005 ◽  
Vol 19 (8) ◽  
pp. 2175-2186 ◽  
Author(s):  
Tracy Xiao Cui ◽  
Graciela Piwien-Pilipuk ◽  
Jeffrey S. Huo ◽  
Julianne Kaplani ◽  
Roland Kwok ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Transcriptional Activation ◽  
Binding Protein ◽  
Enhancer Binding Protein ◽  
Ccaat Enhancer Binding Protein

scholarly journals CCAAT-enhancer-binding protein α (C/EBPα) is required for the thyroid hormone but not the retinoic acid induction of phosphoenolpyruvate carboxykinase (PEPCK) gene transcription

1997 ◽  
Vol 322 (1) ◽  
pp. 343-349 ◽  
Author(s):  
Edwards A. PARK ◽  
Shulan SONG ◽  
Michelle OLIVE ◽  
William J. ROESLER
Keyword(s):  
Retinoic Acid ◽  
Thyroid Hormone ◽  
Dna Binding ◽  
Binding Site ◽  
Transcriptional Activation ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Binding Protein ◽  
Dominant Negative ◽  
Enhancer Binding Protein ◽  
Ccaat Enhancer Binding Protein

Transcription of the gene for phosphoenolpyruvate carboxykinase (PEPCK) is stimulated by cAMP, the thyroid hormone tri-iodothyronine (T3) and retinoic acid (RA). Regulation of PEPCK transcription by T3 involves two sites in the promoter including a thyroid-hormone-response element (TRE) and a CCAAT-enhancer-binding protein (C/EBP) binding site called P3(I). Mutation of either the TRE or P3(I) eliminates the T3 response. In this study, we examined the role of C/EBPs in the induction of PEPCK transcription by T3 and RA. PEPCK-CAT vectors were transfected into HepG2 cells. Co-transfection of a dominant negative C/EBP eliminated the T3 stimulation indicating that a member of the C/EBP family is required. To determine which C/EBP isoform was required, Gal4 fusion proteins were created that contained the Gal4 DNA-binding domain ligated to the transcriptional activation domain of C/EBPα, C/EBPβ or the cAMP-responsive-element-binding protein. A Gal4 DNA-binding site was introduced into the P3(I) site of the PEPCK-CAT vector. Only co-transfection of the Gal4-C/EBPα vector was able to restore T3 responsiveness to the PEPCK-CAT vector. The T3 and RA receptors are members of the nuclear receptor superfamily and bind to repeats of the AGGTCA motif. We found that the RA receptor can bind to sequences within the PEPCK-TRE and contribute to RA responsiveness of the PEPCK gene. However, the RA induction of PEPCK transcription was found to be independent of C/EBPs, further demonstrating the specificity of the involvement of C/EBPα in the T3 effect.

scholarly journals Ethanolamine Catabolism in Pseudomonas aeruginosa PAO1 Is Regulated by the Enhancer-Binding Protein EatR (PA4021) and the Alternative Sigma Factor RpoN

2016 ◽  
Vol 198 (17) ◽  
pp. 2318-2329 ◽  
Author(s):  
Benjamin R. Lundgren ◽  
Zaara Sarwar ◽  
Atahualpa Pinto ◽  
Jack G. Ganley ◽  
Christopher T. Nomura
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Transcriptional Activation ◽  
Sigma Factor ◽  
Target Genes ◽  
Binding Protein ◽  
Acetaldehyde Dehydrogenase ◽  
Content Type ◽  
Catabolic Genes ◽  
Enhancer Binding Protein ◽  
Regulatory Loop

ABSTRACTAlthough genes encoding enzymes and proteins related to ethanolamine catabolism are widely distributed in the genomes ofPseudomonasspp., ethanolamine catabolism has received little attention among this metabolically versatile group of bacteria. In an attempt to shed light on this subject, this study focused on defining the key regulatory factors that govern the expression of the central ethanolamine catabolic pathway inPseudomonas aeruginosaPAO1. This pathway is encoded by thePA4022-eat-eutBCoperon and consists of a transport protein (Eat), an ethanolamine-ammonia lyase (EutBC), and an acetaldehyde dehydrogenase (PA4022). EutBC is an essential enzyme in ethanolamine catabolism because it hydrolyzes this amino alcohol into ammonia and acetaldehyde. The acetaldehyde intermediate is then converted into acetate in a reaction catalyzed by acetaldehyde dehydrogenase. Using a combination of growth analyses and β-galactosidase fusions, the enhancer-binding protein PA4021 and the sigma factor RpoN were shown to be positive regulators of thePA4022-eat-eutBCoperon inP. aeruginosaPAO1. PA4021 and RpoN were required for growth on ethanolamine, and both of these regulatory proteins were essential for induction of thePA4022-eat-eutBCoperon. Unexpectedly, the results indicate that acetaldehyde (and not ethanolamine) serves as the inducer molecule that is sensed by PA4021 and leads to the transcriptional activation of thePA4022-eat-eutBCoperon. Due to its regulatory role in ethanolamine catabolism, PA4021 was given the name EatR. Both EatR and its target genes are conserved in several otherPseudomonasspp., suggesting that these bacteria share a mechanism for regulating ethanolamine catabolism.IMPORTANCEThe results of this study provide a basis for understanding ethanolamine catabolism and its regulation inPseudomonas aeruginosaPAO1. Interestingly, expression of the ethanolamine-catabolic genes in this bacterium was found to be under the control of a positive-feedback regulatory loop in a manner dependent on the transcriptional regulator PA4021, the sigma factor RpoN, and the metabolite acetaldehyde. Previously characterized regulators of ethanolamine catabolism are known to sense and respond directly to ethanolamine. In contrast, PA4021 (EatR) appears to monitor the intracellular levels of free acetaldehyde and responds through transcriptional activation of the ethanolamine-catabolic genes. This regulatory mechanism is unique and represents an alternative strategy used by bacteria to govern the acquisition of ethanolamine from their surroundings.

Sign in / Sign up

Export Citation Format

Share Document