Evidence that the high affinity C4-dicarboxylate transport system of Rhodobacter capsulatus is a novel type of periplasmic permease

1993 ◽  
Vol 21 (4) ◽  
pp. 343S-343S ◽  
Author(s):  
JASON A FORWARD ◽  
MARK C BEHRENDT ◽  
DAVID J KELLY
Keyword(s):  
Transport System ◽  
Rhodobacter Capsulatus ◽  
High Affinity ◽  
Dicarboxylate Transport

scholarly journals Overlapping and Specialized Functions of the Molybdenum-Dependent Regulators MopA and MopB in Rhodobacter capsulatus

2006 ◽  
Vol 188 (24) ◽  
pp. 8441-8451 ◽  
Author(s):  
Jessica Wiethaus ◽  
Andrea Wirsing ◽  
Franz Narberhaus ◽  
Bernd Masepohl
Keyword(s):  
Transport System ◽  
Dna Sequences ◽  
Target Genes ◽  
Rhodobacter Capsulatus ◽  
Binding Protein ◽  
Transcriptional Unit ◽  
Purple Bacterium ◽  
Promoter Regions ◽  
Mobility Shift ◽  
High Affinity

ABSTRACT The phototrophic purple bacterium Rhodobacter capsulatus encodes two similar but functionally not identical molybdenum-dependent regulator proteins (MopA and MopB), which are known to replace each other in repression of the modABC genes (coding for an ABC-type high-affinity Mo transport system) and anfA (coding for the transcriptional activator of Fe-nitrogenase genes). We identified further Mo-regulated (mor) genes coding for a putative ABC-type transport system of unknown function (MorABC) and a putative Mo-binding protein (Mop). The genes coding for MopA and the ModABC transporter form part of a single transcriptional unit, mopA-modABCD, as shown by reverse transcriptase PCR. Immediately upstream of mopA and transcribed in the opposite direction is mopB. The genes coding for the putative MorABC transporter belong to two divergently transcribed operons, morAB and morC. Expression studies based on lacZ reporter gene fusions in mutant strains defective for either MopA, MopB, or both revealed that the regulators substitute for each other in Mo-dependent repression of morAB and morC. Specific Mo-dependent activation of the mop gene by MopA, but not MopB, was found to control the putative Mo-binding protein. Both MopA and MopB are thought to bind to conserved DNA sequences with dyad symmetry in the promoter regions of all target genes. The positions of these so-called Mo boxes relative to the transcription start sites (as determined by primer extension analyses) differed between Mo-repressed genes and the Mo-activated mop gene. DNA mobility shift assays showed that MopA and MopB require molybdenum to bind to their target sites with high affinity.

Regulation of the High-Affinity Nitrate Transport System in Wheat Roots by Exogenous Abscisic Acid and Glutamine

2007 ◽  
Vol 49 (12) ◽  
pp. 1719-1725 ◽  
Author(s):  
Chao Cai ◽  
Xue-Qiang Zhao ◽  
Yong-Guan Zhu ◽  
Bin Li ◽  
Yi-Ping Tong ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Transport System ◽  
Nitrate Transport ◽  
Wheat Roots ◽  
High Affinity

scholarly journals RCO-3 and COL-26 form an external-to-internal module that regulates the dual-affinity glucose transport system in Neurospora crassa

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jinyang Li ◽  
Qian Liu ◽  
Jingen Li ◽  
Liangcai Lin ◽  
Xiaolin Li ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Neurospora Crassa ◽  
Glucose Transport ◽  
Transport System ◽  
Rational Design ◽  
Glucose Sensor ◽  
Glucose Transporters ◽  
Glucose Fluctuation ◽  
High Affinity ◽  
Glucose Transport System

Abstract Background Low- and high-affinity glucose transport system is a conserved strategy of microorganism to cope with environmental glucose fluctuation for their growth and competitiveness. In Neurospora crassa, the dual-affinity glucose transport system consists of a low-affinity glucose transporter GLT-1 and two high-affinity glucose transporters HGT-1/HGT-2, which play diverse roles in glucose transport, carbon metabolism, and cellulase expression regulation. However, the regulation of this dual-transporter system in response to environmental glucose fluctuation is not yet clear. Results In this study, we report that a regulation module consisting of a downstream transcription factor COL-26 and an upstream non-transporting glucose sensor RCO-3 regulates the dual-affinity glucose transport system in N. crassa. COL-26 directly binds to the promoter regions of glt-1, hgt-1, and hgt-2, whereas RCO-3 is an upstream factor of the module whose deletion mutant resembles the Δcol-26 mutant phenotypically. Transcriptional profiling analysis revealed that Δcol-26 and Δrco-3 mutants had similar transcriptional profiles, and both mutants had impaired response to a glucose gradient. We also showed that the AMP-activated protein kinase (AMPK) complex is involved in regulation of the glucose transporters. AMPK is required for repression of glt-1 expression in starvation conditions by inhibiting the activity of RCO-3. Conclusions RCO-3 and COL-26 form an external-to-internal module that regulates the glucose dual-affinity transport system. Transcription factor COL-26 was identified as the key regulator. AMPK was also involved in the regulation of the dual-transporter system. Our findings provide novel insight into the molecular basis of glucose uptake and signaling in filamentous fungi, which may aid in the rational design of fungal strains for industrial purposes.

scholarly journals Functional Characterization of a High-Affinity Choline Transport System in Human Keratinocytes

2002 ◽  
Vol 119 (1) ◽  
pp. 118-121 ◽  
Author(s):  
Kathrin Hoffmann ◽  
Franziska Grafe ◽  
Wolfgang Wohlrab ◽  
Reinhard H. Neubert ◽  
Matthias Brandsch
Keyword(s):  
Transport System ◽  
Functional Characterization ◽  
Human Keratinocytes ◽  
Choline Transport ◽  
High Affinity

scholarly journals Corrigendum to: A high affinity nitrate transport system from Chlamydomonas requires two gene products (FEBS 23233)

FEBS Letters ◽  
2000 ◽  
Vol 481 (1) ◽  
pp. 88-88
Author(s):  
Jing-Jiang Zhou ◽  
Emilio Fernández ◽  
Aurora Galván ◽  
Anthony J. Miller
Keyword(s):  
Transport System ◽  
Nitrate Transport ◽  
Gene Products ◽  
High Affinity
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