Transcriptional regulation of a leucine-responsive regulatory protein for directly controlling lincomycin biosynthesis in Streptomyces lincolnensis

2020 ◽  
Vol 104 (6) ◽  
pp. 2575-2587 ◽  
Author(s):  
Yurong Xu ◽  
Yaqian Tang ◽  
Nian Wang ◽  
Jing Liu ◽  
Xinlu Cai ◽  
...  
Microbiology ◽  
2003 ◽  
Vol 149 (11) ◽  
pp. 3073-3081 ◽  
Author(s):  
Gerardo Medina ◽  
Katy Juárez ◽  
Rafael Díaz ◽  
Gloria Soberón-Chávez

The Pseudomonas aeruginosa rhlR gene encodes the transcriptional regulator RhlR which has a central role in the quorum-sensing response. Different gene products involved in bacterial pathogenesis are regulated at the transcriptional level by two quorum-sensing response systems, Las and Rhl. The expression of rhlR has been reported to be under the control of the Las system, but its transcriptional regulation has not been studied in detail. Here, the rhlR promoter region has been characterized and shown to present four different transcription start sites, two of which are included in the upstream gene (rhlB) coding region. It was found that rhlR expression is not only dependent on LasR but also on different regulatory proteins such as Vfr and RhlR itself, and also on the alternative sigma factor σ 54. It is reported that rhlR expression is partially LasR-independent under certain culture conditions and is strongly influenced by environmental factors.


2001 ◽  
Vol 47 (4) ◽  
pp. 359-367 ◽  
Author(s):  
Jiping Li ◽  
Bernard R Glick

Based on DNA sequence analysis and 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, the region of DNA immediately upstream of the Enterobacter cloacae UW4 ACC deaminase gene (acdS) contains several features that appear to be involved in its transcriptional regulation. In the present study, the 5' upstream region of acdS was cloned into the promoter-probe vector, pQF70, which carries the promoterless luciferase gene (luxAB), and luciferase expression was monitored. The data obtained from studying the expression of the luciferase gene showed that (i) a leucine responsive regulatory protein (LRP)-like protein encoded within the upstream region is located on the opposite strand from acdS under the control of a promoter stronger than the one responsible for acdS transcription, (ii) luciferase gene expression required both ACC and the LRP-like protein, (iii) luciferase expression was increased three-fold under anaerobic conditions, consistent with the involvement of a fumarate-nitrate reduction (FNR)-like regulatory protein box within the upstream region, and (iv) the addition of leucine to the growth medium decreased luciferase activity in the presence of ACC and increased luciferase activity in the absence of ACC, consistent with leucine acting as a regulator of the expression of the LRP-like protein.Key words: plant growth promotion, ethylene, ACC deaminase, regulation, Enterobacter cloacae.


2012 ◽  
Vol 194 (18) ◽  
pp. 5020-5033 ◽  
Author(s):  
Verónica I. Martínez-Santos ◽  
Abraham Medrano-López ◽  
Zeus Saldaña ◽  
Jorge A. Girón ◽  
José L. Puente

ABSTRACTEnteropathogenic (EPEC) and enterohemorrhagic (EHEC)Escherichia coliare clinically important diarrheagenic pathogens that adhere to the intestinal epithelial surface. TheE. colicommon pili (ECP), or meningitis-associated and temperature-regulated (MAT) fimbriae, are ubiquitous among both commensal and pathogenicE. colistrains and play a role as colonization factors by promoting the interaction between bacteria and host epithelial cells and favoring interbacterial interactions in biofilm communities. The first gene of theecpoperon encodes EcpR (also known as MatA), a proposed regulatory protein containing a LuxR-like C-terminal helix-turn-helix (HTH) DNA-binding motif. In this work, we analyzed the transcriptional regulation of theecpgenes and the role of EcpR as a transcriptional regulator. EHEC and EPECecpRmutants produce less ECP, while plasmids expressing EcpR increase considerably the expression of EcpA and production of ECP. Theecpgenes are transcribed as an operon from a promoter located 121 bp upstream of the start codon ofecpR. EcpR positively regulates this promoter by binding to two TTCCT boxes distantly located upstream of theecppromoter, thus enhancing expression of downstreamecpgenes, leading to ECP production. EcpR mutants in the putative HTH DNA-binding domain are no longer able to activateecpexpression or bind to the TTCCT boxes. EcpR-mediated activation is aided by integration host factor (IHF), which is essential for counteracting the repression exerted by histone-like nucleoid-structuring protein (H-NS) on theecppromoter. This work demonstrates evidence about the interplay between a novel member of a diverse family of regulatory proteins and global regulators in the regulation of a fimbrial operon.


2009 ◽  
Vol 234 (8) ◽  
pp. 880-907 ◽  
Author(s):  
Holly A. LaVoie ◽  
Steven R. King

Expression of the genes that mediate the first steps in steroidogenesis, the steroidogenic acute regulatory protein (STARD1), the cholesterol side-chain cleavage enzyme, cytochrome P450scc (CYP11A1) and 3β-hydroxysteroid dehydrogenase/Δ5-Δ4 isomerase (HSD3B), is tightly controlled by a battery of transcription factors in the adrenal cortex, the gonads and the placenta. These genes generally respond to the same hormones that stimulate steroid production through common pathways such as cAMP signaling and common actions on their promoters by proteins such as NR5A and GATA family members. However, there are distinct temporal, tissue and species-specific differences in expression between the genes that are defined by combinatorial regulation and unique promoter elements. This review will provide an overview of the hormonal and transcriptional regulation of the STARD1, CYP11A1 and specific steroidogenic HSD3B genes in the adrenal, testis, ovary and placenta and discuss the current knowledge regarding the key transcriptional factors involved.


2002 ◽  
Vol 30 (4) ◽  
pp. 726-728 ◽  
Author(s):  
M. Neonaki ◽  
D. Cunninghame Graham ◽  
K. N. White ◽  
A. Bomford

Cellular iron homoeostasis is maintained by iron sensor proteins known as iron-regulatory proteins (IRPs), which act post-transcriptionally by binding RNA stem-loop structures, termed iron-responsive elements (IREs), present on the mRNAs of proteins involved in iron storage, utilization and transport. IRP1 is a bifunctional protein that can act either as a cytoplasmic aconitase or as an IRE-binding protein. The RNA-binding activity of IRP1 is regulated post-translationally by the insertion or extrusion of a 4Fe-4S cluster, without changes in the levels of protein. In hereditary haemochromatosis (HH) accumulation of iron in parenchymal tissues, including the liver, occurs, possibly through dysfunctional IRP1. Investigation of IRP1 expression in liver biopsies from HH patients showed that the protein is completely absent or markedly reduced in heavily iron-loaded HH patients. Real-time PCR was then conducted in an attempt to investigate the mRNA levels and establish the underlying mechanism behind the disappearing act of IRP1. The two possibilities are: transcriptional regulation (through the inhibition of transcription) or post-transcriptional regulation (either through increased turnover of protein or inhibition of translation) of IRP1. Preliminary data suggest that transcription of IRP1 is not affected by chronic iron overload, and down-regulation may be attributable instead to degradation of the protein.


2020 ◽  
Vol 21 (23) ◽  
pp. 9319
Author(s):  
Toru Suzuki ◽  
Shungo Adachi ◽  
Chisato Kikuguchi ◽  
Shinsuke Shibata ◽  
Saori Nishijima ◽  
...  

Transcripts of alpha-fetoprotein (Afp), H19, and insulin-like growth factor 2 (Igf2) genes are highly expressed in mouse fetal liver, but decrease drastically during maturation. While transcriptional regulation of these genes has been well studied, the post-transcriptional regulation of their developmental decrease is poorly understood. Here, we show that shortening of poly(A) tails and subsequent RNA decay are largely responsible for the postnatal decrease of Afp, H19, and Igf2 transcripts in mouse liver. IGF2 mRNA binding protein 1 (IMP1), which regulates stability and translation efficiency of target mRNAs, binds to these fetal liver transcripts. When IMP1 is exogenously expressed in mouse adult liver, fetal liver transcripts show higher expression and possess longer poly(A) tails, suggesting that IMP1 stabilizes them. IMP1 declines concomitantly with fetal liver transcripts as liver matures. Instead, RNA-binding proteins (RBPs) that promote RNA decay, such as cold shock domain containing protein E1 (CSDE1), K-homology domain splicing regulatory protein (KSRP), and CUG-BP1 and ETR3-like factors 1 (CELF1), bind to 3′ regions of fetal liver transcripts. These data suggest that transitions among RBPs associated with fetal liver transcripts shift regulation from stabilization to decay, leading to a postnatal decrease in those fetal transcripts.


PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249379
Author(s):  
Ying Zhou ◽  
Tianying Zhong ◽  
Wenjing Wei ◽  
Zhuhua Wu ◽  
Anping Yang ◽  
...  

Tuberculosis caused by the pathogen Mycobacterium tuberculosis (MTB), remains a significant threat to global health. Elucidating the mechanisms of essential MTB genes provides an important theoretical basis for drug exploitation. Gene mtsp17 is essential and is conserved in the Mycobacterium genus. Although Mtsp17 has a structure closely resembling typical steroidogenic acute regulatory protein-related lipid transfer (START) family proteins, its biological function is different. This study characterizes the transcriptomes of Mycobacterium smegmatis to explore the consequences of mtsp17 downregulation on gene expression. Suppression of the mtsp17 gene resulted in significant down-regulation of 3% and upregulation of 1% of all protein-coding genes. Expression of desA1, an essential gene involved in mycolic acid synthesis, and the anti-SigF antagonist MSMEG_0586 were down-regulated in the conditional Mtsp17 knockout mutant and up-regulated in the Mtsp17 over-expression strain. Trends in the changes of 70 of the 79 differentially expressed genes (Log2 fold change > 1.5) in the conditional Mtsp17 knockout strain were the same as in the SigF knockout strain. Our data suggest that Mtsp17 is likely an activator of desA1 and Mtsp17 regulates the SigF regulon by SigF regulatory pathways through the anti-SigF antagonist MSMEG_0586. Our findings indicate the role of Mtsp17 may be in transcriptional regulation, provide new insights into the molecular mechanisms of START family proteins, and uncover a new node in the regulatory network of mycobacteria.


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