Linked Life Data

7823040

Source:http://linkedlifedata.com/resource/pubmed/id/7823040

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1995-2-16
pubmed:abstractText
Both neutralophilic Bacillus subtilis and alkaliphilic Bacillus firmus OF4 depend upon electrogenic Na+/H+ antiporters, which are energized by the gradients established by respiration-coupled proton extrusion, to achieve Na(+)-resistance and pH homeostasis when the external pH is very alkaline. The interplay of proton and sodium cycles is discussed. In B. subtilis, pH homeostasis, up to pH9, can be achieved using K+ when Na+ is unavailable or when the gene encoding the Na+/H+ antiporter that is involved in Na(+)-dependent pH homeostasis is disrupted. That gene is a member of the tetracycline efflux family of genes. A second gene, encoding a Na+/H+ antiporter that functions in Na(+)-resistance, has been identified, and candidates for the K+/H+ antiporter genes are under investigation. Aggregate Na+/H+ antiport activity in B. subtilis is as much as 10 times lower than in the alkaliphile, and the neutralophile cannot regulate its internal pH upon a shift to pH 10.5. Upon such a shift, there is a pronounced reduction in the generation of a primary electrochemical proton gradient. The alkaliphile, by contrast, maintains substantial driving forces and regulates its internal pH in an exclusively Na(+)-coupled manner upon shifts to either pH 8.7 or 10.5. One gene locus has been identified and a second locus has been inferred as encoding relevant antiporter activities.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-0949
pubmed:author
pubmed:issnType
Print
pubmed:volume
196
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
457-70
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
The role of monovalent cation/proton antiporters in Na(+)-resistance and pH homeostasis in Bacillus: an alkaliphile versus a neutralophile.
pubmed:affiliation
Department of Biochemistry, Mount Sinai School of Medicine of the CUNY, NY 10029.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, Non-P.H.S., Review