Linked Life Data

11401701

Source:http://linkedlifedata.com/resource/pubmed/id/11401701

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2001-6-12
pubmed:abstractText
The gene hetN encodes a putative oxidoreductase that is known to suppress heterocyst differentiation when present on a multicopy plasmid in Anabaena sp. PCC 7120. To mimic the hetN null phenotype and to examine where HetN acts in the regulatory cascade that controls heterocyst differentiation, we replaced the native chromosomal hetN promoter with the copper-inducible petE promoter. In the presence of copper, heterocyst formation was suppressed in undifferentiated filaments. When hetN expression was turned off by transferring cells to media lacking copper, the filaments initially displayed the wild-type pattern of single heterocysts but, 48 h after the induction of heterocyst formation, a pattern of multiple contiguous heterocysts predominated. Suppression of heterocyst formation by HetN appears to occur both upstream and downstream of the positive regulator HetR: overexpression of hetN in undifferentiated filaments prevents the wild-type pattern of hetR expression as well as the multiheterocyst phenotype normally observed when hetR is expressed from an inducible promoter. Green fluorescent protein fusions show that the expression of hetN in wild-type filaments normally occurs primarily in heterocysts. We propose that HetN is normally involved in the maintenance of heterocyst spacing after the initial heterocyst pattern has been established, but ectopic expression of hetN can also block the initial establishment of the pattern.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
40
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
941-50
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
The role of HetN in maintenance of the heterocyst pattern in Anabaena sp. PCC 7120.
pubmed:affiliation
Department of Molecular Genetics and Cell Biology, University of Chicago, 920 East 58th Street, Chicago, IL 60637 USA. s.callahan@uchicago.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.