Identification and characterization of the regulatory elements of the inducible acetamidase operon from Mycobacterium smegmatis

2007 ◽  
Vol 53 (5) ◽  
pp. 599-606 ◽  
Author(s):  
Selvakumar Subbian ◽  
Sujatha Narayanan
Keyword(s):  
Mycobacterium Smegmatis ◽  
Regulatory Elements ◽  
Growth Conditions ◽  
Open Reading Frames ◽  
Reporter System ◽  
Mobility Shift ◽  
Crude Cell Lysate ◽  
Multiple Promoters ◽  
Promoter Probe ◽  
Mobility Shift Assay

The highly inducible acetamidase promoter from Mycobacterium smegmatis has been used as a tool in the study of mycobacterial genetics. The 4.2 kb acetamidase operon contains four putative open reading frames (ORFs) (amiC, amiA, amiD, and amiS) upstream of the 1.2 kb acetamidase ORF (amiE). In this article, using electrophoretic mobility shift assay and promoter probe analyses with a lacZ reporter system, we show the position of three putative operators within the acetamidase operon in M. smegmatis. Results from these studies reinforce previous findings about the involvement of multiple promoters in the regulation of acetamidase gene expression. Each of the identified operators are positioned upstream of the respective promoter reported in previous studies. We also found that the crude cell lysate of M. smegmatis containing potential regulators, obtained from bacteria grown under inducing or noninducing conditions, binds to specific operators. The binding affinity of each operator with its cognate regulator is significantly different from the other. This supports not only the previous model of acetamidase gene regulation in M. smegmatis but also explains the role of these operators in controlling the expression of respective promoters under different growth conditions.

The positive regulatory function of the 5'-proximal open reading frames in GCN4 mRNA can be mimicked by heterologous, short coding sequences

1988 ◽  
Vol 8 (9) ◽  
pp. 3827-3836
Author(s):  
N P Williams ◽  
P P Mueller ◽  
A G Hinnebusch
Keyword(s):  
Translational Control ◽  
Normal Growth ◽  
Regulatory Elements ◽  
Growth Conditions ◽  
Open Reading Frames ◽  
Regulatory Function ◽  
Yeast Saccharomyces Cerevisiae ◽  
Reading Frame ◽  
Yeast Genes ◽  
Reading Frames

Translational control of GCN4 expression in the yeast Saccharomyces cerevisiae is mediated by multiple AUG codons present in the leader of GCN4 mRNA, each of which initiates a short open reading frame of only two or three codons. Upstream AUG codons 3 and 4 are required to repress GCN4 expression in normal growth conditions; AUG codons 1 and 2 are needed to overcome this repression in amino acid starvation conditions. We show that the regulatory function of AUG codons 1 and 2 can be qualitatively mimicked by the AUG codons of two heterologous upstream open reading frames (URFs) containing the initiation regions of the yeast genes PGK and TRP1. These AUG codons inhibit GCN4 expression when present singly in the mRNA leader; however, they stimulate GCN4 expression in derepressing conditions when inserted upstream from AUG codons 3 and 4. This finding supports the idea that AUG codons 1 and 2 function in the control mechanism as translation initiation sites and further suggests that suppression of the inhibitory effects of AUG codons 3 and 4 is a general consequence of the translation of URF 1 and 2 sequences upstream. Several observations suggest that AUG codons 3 and 4 are efficient initiation sites; however, these sequences do not act as positive regulatory elements when placed upstream from URF 1. This result suggests that efficient translation is only one of the important properties of the 5' proximal URFs in GCN4 mRNA. We propose that a second property is the ability to permit reinitiation following termination of translation and that URF 1 is optimized for this regulatory function.

scholarly journals Identification of Chlamydia trachomatis Genomic Sequences Recognized by Chlamydial Divalent Cation-Dependent Regulator A (DcrA)

2005 ◽  
Vol 187 (2) ◽  
pp. 443-448 ◽  
Author(s):  
Annette Rau ◽  
Susan Wyllie ◽  
Judy Whittimore ◽  
Jane E. Raulston
Keyword(s):  
Chlamydia Trachomatis ◽  
Divalent Cation ◽  
Open Reading Frames ◽  
Genomic Sequences ◽  
Mobility Shift ◽  
Reading Frame ◽  
E Coli ◽  
Resultant Data ◽  
Mobility Shift Assay ◽  
Titration Assay

ABSTRACT The Chlamydia trachomatis divalent cation-dependent regulator (DcrA), encoded by open reading frame CT296, is a distant relative of the ferric uptake regulator (Fur) family of iron-responsive regulators. Chlamydial DcrA specifically binds to a consensus Escherichia coli Fur box and is able to complement an E. coli Fur mutant. In this report, the E. coli Fur titration assay (FURTA) was used to locate chlamydial genomic sequences that are recognized by E. coli Fur. The predictive regulatory regions of 28 C. trachomatis open reading frames contained sequences functionally recognized by E. coli Fur; targets include components of the type III secretion pathway, elements involved in envelope and cell wall biogenesis, predicted transport proteins, oxidative defense enzymes, and components of metabolic pathways. Selected FURTA-positive sequences were subsequently examined for recognition by C. trachomatis DcrA using an electrophoretic mobility shift assay. The resultant data show that C. trachomatis DcrA binds to native chlamydial genomic sequences and, overall, substantiate a functional relationship between chlamydial DcrA and the Fur family of regulators.

scholarly journals Transcriptional and Functional Analysis of the Neisseria gonorrhoeae Fur Regulon

2009 ◽  
Vol 192 (1) ◽  
pp. 77-85 ◽  
Author(s):  
Lydgia A. Jackson ◽  
Thomas F. Ducey ◽  
Michael W. Day ◽  
Jeremy B. Zaitshik ◽  
Joshua Orvis ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Transcriptional Control ◽  
Cell Communication ◽  
Essential Element ◽  
Open Reading Frames ◽  
Promoter Regions ◽  
Mobility Shift ◽  
Sequence Logos ◽  
Mobility Shift Assay

ABSTRACT To ensure survival in the host, bacteria have evolved strategies to acquire the essential element iron. In Neisseria gonorrhoeae, the ferric uptake regulator Fur regulates metabolism through transcriptional control of iron-responsive genes by binding conserved Fur box (FB) sequences in promoters during iron-replete growth. Our previous studies showed that Fur also controls the transcription of secondary regulators that may, in turn, control pathways important to pathogenesis, indicating an indirect role for Fur in controlling these downstream genes. To better define the iron-regulated cascade of transcriptional control, we combined three global strategies—temporal transcriptome analysis, genomewide in silico FB prediction, and Fur titration assays (FURTA)—to detect genomic regions able to bind Fur in vivo. The majority of the 300 iron-repressed genes were predicted to be of unknown function, followed by genes involved in iron metabolism, cell communication, and intermediary metabolism. The 107 iron-induced genes encoded hypothetical proteins or energy metabolism functions. We found 28 predicted FBs in FURTA-positive clones in the promoters and within the open reading frames of iron-repressed genes. We found lower levels of conservation at critical thymidine residues involved in Fur binding in the FB sequence logos of FURTA-positive clones with intragenic FBs than in the sequence logos generated from FURTA-positive promoter regions. In electrophoretic mobility shift assay studies, intragenic FBs bound Fur with a lower affinity than intergenic FBs. Our findings further indicate that transcription under iron stress is indirectly controlled by Fur through 12 potential secondary regulators.

Cyclic AMP receptor protein is a repressor of adenylyl cyclase gene cyaA in Yersinia pestis

2013 ◽  
Vol 59 (5) ◽  
pp. 304-310 ◽  
Author(s):  
Shi Qu ◽  
Yiquan Zhang ◽  
Lei Liu ◽  
Li Wang ◽  
Yanping Han ◽  
...  
Keyword(s):  
Cyclic Amp ◽  
Adenylyl Cyclase ◽  
Yersinia Pestis ◽  
Core Promoter ◽  
Growth Conditions ◽  
Receptor Protein ◽  
Camp Production ◽  
Mobility Shift ◽  
Cyclic Amp Receptor Protein ◽  
Mobility Shift Assay

Yersinia pestis is one of the most dangerous pathogens. The cyclic AMP receptor protein (CRP) is required for the full virulence of Y. pestis, and it acts as a transcriptional regulator to control a large regulon, which includes several virulence-associated genes. The regulatory action of CRP is triggered only by binding to the small molecule cofactor cyclic AMP (cAMP). cAMP is synthesized from adenosine triphosphate by the adenylyl cyclase encoded by cyaA. In the present work, the regulation of crp and cyaA by CRP was investigated by primer extension, LacZ fusion, electrophoretic mobility shift assay, and DNase I footprinting. No transcriptional regulatory association between CRP and its own gene could be detected under the growth conditions tested. In contrast, CRP bound to a DNA site overlapping the core promoter −10 region of cyaA to repress the cyaA transcription. The determination of cellular cAMP levels further verified that CRP negatively controlled cAMP production. Repression of cAMP production by CRP through acting on the cAMP synthesase gene cyaA would represent a mechanism of negative automodulation of cellular CRP function.

scholarly journals TaWRKY13-A Serves as a Mediator of Jasmonic Acid-Related Leaf Senescence by Modulating Jasmonic Acid Biosynthesis

2021 ◽  
Vol 12 ◽  
Author(s):  
Hualiang Qiao ◽  
Yongwei Liu ◽  
Lingling Cheng ◽  
Xuelin Gu ◽  
Pengcheng Yin ◽  
...  
Keyword(s):  
Jasmonic Acid ◽  
Leaf Senescence ◽  
Brachypodium Distachyon ◽  
Wrky Transcription Factor ◽  
Luciferase Reporter ◽  
Virus Induced Gene Silencing ◽  
Reporter System ◽  
Mobility Shift ◽  
Yield And Quality ◽  
Mobility Shift Assay

Leaf senescence is crucial for crop yield and quality. Transcriptional regulation is a key step for integrating various senescence-related signals into the nucleus. However, few regulators of senescence implicating transcriptional events have been functionally characterized in wheat. Based on our RNA-seq data, we identified a WRKY transcription factor, TaWRKY13-A, that predominately expresses at senescent stages. By using the virus-induced gene silencing (VIGS) method, we manifested impaired transcription of TaWRKY13-A leading to a delayed leaf senescence phenotype in wheat. Moreover, the overexpression (OE) of TaWRKY13-A accelerated the onset of leaf senescence under both natural growth condition and darkness in Brachypodium distachyon and Arabidopsis thaliana. Furthermore, by physiological and molecular investigations, we verified that TaWRKY13-A participates in the regulation of leaf senescence via jasmonic acid (JA) pathway. The expression of JA biosynthetic genes, including AtLOX6, was altered in TaWRKY13-A-overexpressing Arabidopsis. We also demonstrated that TaWRKY13-A can interact with the promoter of AtLOX6 and TaLOX6 by using the electrophoretic mobility shift assay (EMSA) and luciferase reporter system. Consistently, we detected a higher JA level in TaWRKY13-A-overexpressing lines than that in Col-0. Moreover, our data suggested that TaWRKY13-A is partially functional conserved with AtWRKY53 in age-dependent leaf senescence. Collectively, this study manifests TaWRKY13-A as a positive regulator of JA-related leaf senescence, which could be a new clue for molecular breeding in wheat.

scholarly journals Roles of Multiple Promoters in Transcription of Ribosomal DNA: Effects of Growth Conditions on Precursor rRNA Synthesis in Mycobacteria

1998 ◽  
Vol 180 (21) ◽  
pp. 5756-5761 ◽  
Author(s):  
J. A. Gonzalez-y-Merchand ◽  
M. J. Colston ◽  
R. A. Cox
Keyword(s):  
Mycobacterium Smegmatis ◽  
High Growth ◽  
Growth Conditions ◽  
Model Organisms ◽  
Rrna Synthesis ◽  
Phase Growth ◽  
Balanced Growth ◽  
Stages Of Growth ◽  
Multiple Promoters ◽  
Single Operon

ABSTRACT The roles of multiple promoters in the synthesis of rRNA under different conditions of growth were investigated, using two mycobacterial species as model organisms. When Mycobacterium smegmatis was grown under optimal conditions, its two rRNA operons contributed equally, with two promoters, one from each operon, being responsible for most transcripts. In stationary-phase growth or balanced growth under carbon starvation conditions, one operon (rrnA f) dominated and its three promoters contributed more equally to the generation of transcripts.Mycobacterium tuberculosis has a single operon with two promoters, one of which generated 80% of transcripts, at all stages of growth. We infer that each promoter functions independently according to its intrinsic strength when cells are growing slowly so that one operon with three promoters is roughly equivalent to three operons with one promoter; at high growth rates, occlusion effects reduce the efficiency of multiple promoters to that of a single promoter.

scholarly journals Characterization of the human ephrin-A4 promoter

2002 ◽  
Vol 366 (2) ◽  
pp. 447-458 ◽  
Author(s):  
Else MUNTHE ◽  
Hans-Christian AASHEIM
Keyword(s):  
Tyrosine Kinases ◽  
Promoter Activity ◽  
Regulatory Elements ◽  
Lymphoid Cells ◽  
Transcription Activator ◽  
Mobility Shift ◽  
Specific Expression ◽  
Eph Receptor ◽  
Transcription Activity ◽  
Mobility Shift Assay

Expression of the ephrin-A4 ligand, a family member of ligands binding the Eph receptor tyrosine kinases, is induced after an antigen–receptor stimulation of lymphocytes. To understand the transcription regulation of the ephrin-A4 gene, its promoter was identified and regulating elements were characterized. The ephrin-A4 promoter contains cis elements directing the cell-specific expression. By deletion studies, three specific regions, which were contributing to the transcription activity in lymphoid cells, were localized. In one of these regions, an inverted CCAAT box was identified and shown to bind the transcription activator nuclear factor-Y (NF-Y). The importance of NF-Y binding for the ephrin-A4 promoter activity is shown by a total abrogation of promoter activity after destruction of its binding site. NF-Y binding and activity are also crucially dependent on the integrity of the surrounding sequence. In addition, electrophoretic mobility-shift assay and serial-mutation analysis of the two remaining regulating regions revealed cis regulatory elements contributing to the transcription activity of the ephrin-A4 promoter.

scholarly journals A Simple Method to Detect the Inhibition of Transcription Factor-DNA Binding Due to Protein–Protein Interactions In Vivo

Genes ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 684 ◽  
Author(s):  
Guangzhe Yang ◽  
Dong Chao ◽  
Zhenhua Ming ◽  
Jixing Xia
Keyword(s):  
Dna Binding ◽  
Protein Interactions ◽  
Regulatory Elements ◽  
Inhibitory Effect ◽  
Protein Protein Interactions ◽  
Mobility Shift ◽  
Simple Method ◽  
Mobility Shift Assay ◽  
Aureobasidin A

Binding of transcription factors (TFs) to cis-regulatory elements (DNA) could modulate the expression of downstream genes, while interactions between TFs and other proteins might inhibit them binding to DNA. Nowadays, electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) approaches are usually employed to detect the inhibitory effect. However, EMSA might not reflect the inhibitory effect in vivo. ChIP requires preparation of specific antibody or stable genetic transformation and complicated experimental steps, making it laborious and time-consuming. Here, based on the yeast one-hybrid (Y1H) system, we present a simple method to detect the inhibition of TF–DNA binding due to protein–protein interactions in vivo. When interactions between TFs and other proteins inhibit TFs binding to DNA, the reporter (Aureobasidin A resistance) gene is not activated, thereby inhibiting yeast growth on media containing the AbA antibiotic. Two examples were tested with the newly developed method to demonstrate its feasibility. In conclusion, this method provides an alternative strategy for detecting the inhibition of DNA-binding of TFs due to their interactions with other proteins in vivo.

scholarly journals LplR, a Repressor Belonging to the TetR Family, Regulates Expression of the l-Pantoyl Lactone Dehydrogenase Gene in Rhodococcus erythropolis

2012 ◽  
Vol 78 (22) ◽  
pp. 7923-7930 ◽  
Author(s):  
Dayong Si ◽  
Nobuyuki Urano ◽  
Sakayu Shimizu ◽  
Michihiko Kataoka
Keyword(s):  
Rhodococcus Erythropolis ◽  
Repeat Sequence ◽  
Open Reading Frames ◽  
Negative Regulator ◽  
Wild Type ◽  
Mobility Shift ◽  
Content Type ◽  
Recombinant Cells ◽  
Mobility Shift Assay ◽  
Multicopy Vector

ABSTRACTThel-pantoyl lactone (l-PL) dehydrogenase (LPLDH) gene (lpldh) has been cloned fromRhodococcus erythropolisAKU2103, and addition of 1,2-propanediol (1,2-PD) was shown to be required forlpldhexpression in this strain. In this study, based on an exploration of the nucleotide sequence aroundlpldh, a TetR-like regulator gene, which we designatedlplR, was found upstream oflpldh, and three putative open reading frames existed between the two genes. Disruption oflplRled to 22.8 times higherlpldhexpression, even without 1,2-PD induction, than that in wild-typeR. erythropolisAKU2103 without 1,2-PD addition. Introduction of a multicopy vector carryinglplR(multi-lplR) into the wild-type and ΔlplRstrains led to no detectable LPLDH activity even in the presence of 1,2-PD. The results of an electrophoretic mobility shift assay revealed that purified LplR bound to a 6-bp inverted-repeat sequence located in the promoter/operator region of the operon containinglpldh. These results indicated that LplR is a negative regulator inlpldhexpression. Based on the clarification of the expression mechanism oflpldh, recombinant cells showing high LPLDH activity were constructed and used as a catalyst for the conversion ofl-PL to ketopantoyl lactone. Finally, a promising production process ofd-PL fromdl-PL was constructed.

Sign in / Sign up

Export Citation Format

Share Document