Disease relevance of traR

• Octopine stimulates expression of the traR gene, whose product directly activates other tra genes in the presence of an acylated homoserine lactone called Agrobacterium autoinducer (AAI) [1].

High impact information on traR

• The A. tumefaciens transcriptional activator OccR causes a bend at a target promoter, which is partially relaxed by a plant tumor metabolite [2].
• Here we show that conjugation is regulated directly by a transcriptional activator, TraR, which requires conjugation factor as a coinducer to activate tra gene expression [3].
• Mutational analysis of TraR. Correlating function with molecular structure of a quorum-sensing transcriptional activator [4].
• Conjugal transfer of Agrobacterium tumefaciens Ti plasmids is regulated by quorum sensing via the transcriptional activator TraR and the acyl-homoserine lactone Agrobacterium autoinducer (AAI) [5].
• TraM, an 11.2 kDa antiactivator, modulates the acyl-homoserine lactone-mediated autoinduction of Ti plasmid conjugative transfer by interacting directly with TraR, the quorum-sensing transcriptional activator [6].

Chemical compound and disease context of traR

• Conjugal transfer of Ti plasmids of Agrobacterium tumefaciens is controlled by a quorum-sensing system composed of the transcriptional activator TraR and its acyl-homoserine lactone quormone N-(3-oxo-octanoyl)-L-homoserine lactone (3-oxo-C8-HSL) [7].

Biological context of traR

• Conjugal transfer of the Ti plasmids from Agrobacterium tumefaciens is controlled by autoinduction via the transcriptional activator TraR and the acyl-homoserine lactone ligand, Agrobacterium autoinducer (AAI) [8].
• When co-expressed with lambda cI'::TraR fusions, wild-type TraM mediated quormone-independent dimerization of the transcriptional activator, suggesting that dimers of TraM can multimerize TraR [6].
• OHHL is thought to bind to the LuxR protein, allowing it to act as a positive transcriptional activator in an autoinduction process that physiologically couples cell density (and growth phase) to the expression of the bioluminescence genes [9].
• The binding site of the transcriptional activator VirG from Agrobacterium comprises both conserved and specific nonconserved sequences [10].
• The chimeric transcriptional activator TGV mediates dexamethasone (dx)-inducible and tetracycline (tc)-repressible transgene expression in tobacco (dx-on/ tc-off system) [11].

Associations of traR with chemical compounds

• Although traM was first identified by its octopine-inducible promoter, we now show that induction by octopine requires traR, strongly suggesting that TraR is the direct traM activator [12].
• Conjugal transfer of the Ti plasmid pTiC58 is regulated by a quorum-sensing system involving the transcriptional activator TraR and the acyl homoserine lactone autoinducer N-(3-oxo-octanoyl)-L-homoserine lactone (AAI) [13].
• Three proteins are required to sense and respond to these stimuli: (i) VirA, a transmembrane sensory protein and histidine protein kinase, (ii) VirG, a transcriptional activator which is phosphorylated by phosphoryl VirA, and (iii) ChvE, a periplasmic sugar-binding protein [14].
• The membrane-spanning sensor, a histidine protein kinase, was designated ChvG, and the response regulator, presumably a transcriptional activator, was designated ChvI [15].
• TraI synthesizes the autoinducer pheromone N-(3-oxooctanoyl)-L-homoserine lactone (3-oxo-C8-HSL), while TraR is an 3-oxo-C8-HSL-responsive transcriptional activator [16].

Other interactions of traR

• The suppression could be relieved by increasing the expression of TraR but not by increasing AAI levels. traM is located between traR and traAF on pTiC58 and is transcribed in the clockwise direction [17].
• Expression of these genes, as measured by using the lacZ fusions formed by Tn3HoHo1, required the traI promoter and the transcriptional activator TraR along with its coinducer, AAI [18].
• Controlled expression of the transcriptional activator gene virG in Agrobacterium tumefaciens by using the Escherichia coli lac promoter [19].
• The quorum-sensing transcriptional activator TraR of Agrobacterium tumefaciens, which controls the replication and conjugal transfer of the tumour-inducing (Ti) virulence plasmid, is inhibited by the TraM antiactivator [20].
• Conservation of PcaQ, a transcriptional activator of pca genes for catabolism of phenolic compounds, in Agrobacterium tumefaciens and Rhizobium species [21].

References