Linked Life Data

21784929

Source:http://linkedlifedata.com/resource/pubmed/id/21784929

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
2011-9-14
pubmed:abstractText
Bacillus subtilis is known to accumulate large amounts of the compatible solute proline via de novo synthesis as a stress protectant when it faces high-salinity environments. We elucidated the genetic determinants required for the osmoadaptive proline production from the precursor glutamate. This proline biosynthesis route relies on the proJ-encoded ?-glutamyl kinase, the proA-encoded ?-glutamyl phosphate reductase, and the proH-encoded ?1-pyrroline-5-caboxylate reductase. Disruption of the proHJ operon abolished osmoadaptive proline production and strongly impaired the ability of B. subtilis to cope with high-osmolarity growth conditions. Disruption of the proA gene also abolished osmoadaptive proline biosynthesis but caused, in contrast to the disruption of proHJ, proline auxotrophy. Northern blot analysis demonstrated that the transcription of the proHJ operon is osmotically inducible, whereas that of the proBA operon is not. Reporter gene fusion studies showed that proHJ expression is rapidly induced upon an osmotic upshift. Increased expression is maintained as long as the osmotic stimulus persists and is sensitively linked to the prevalent osmolarity of the growth medium. Primer extension analysis revealed the osmotically controlled proHJ promoter, a promoter that resembles typical SigA-type promoters of B. subtilis. Deletion analysis of the proHJ promoter region identified a 126-bp DNA segment carrying all sequences required in cis for osmoregulated transcription. Our data disclose the presence of ProA-interlinked anabolic and osmoadaptive proline biosynthetic routes in B. subtilis and demonstrate that the synthesis of the compatible solute proline is a central facet of the cellular defense to high-osmolarity surroundings for this soil bacterium.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1098-5530
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
193
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5335-46
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Osmotically controlled synthesis of the compatible solute proline is critical for cellular defense of Bacillus subtilis against high osmolarity.
pubmed:affiliation
Philipps-University Marburg, Department of Biology, Laboratory for Microbiology, Karl-von-Frisch-Str. 8, D-35032 Marburg, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't