Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1995-9-25
pubmed:abstractText
LamB glycoporin has an important general role in carbohydrate uptake during growth at low extracellular sugar concentrations. lamB and mal regulon induction during glucose starvation and glucose-limited continuous culture was investigated using lacZ fusions. A low-level burst of lamB induction occurred upon entry into glucose starvation-induced stationary phase but returned to basal levels during continued nutrient deprivation. Glucose-limited continuous culture elicited much higher expression of transporter genes in the mal regulon, as well as [14C]-maltose-transport activity; malEFG and malKlamB operons in glucose-limited chemostats were expressed to close to half of the level of maltose-induced batch cultures. Limitation-induced expression was dependent on both Crp-cAMP and MalT activation but was independent of RpoS function. As expected for a gene with a Crp-controlled promoter, malT expression was maximal under conditions which elicited the highest cAMP levels, but lamB induction did not behave in a corresponding fashion. Rather, maximal lamB induction occurred at rapid but suboptimal growth rates with micromolar or submicromolar medium glucose. Maximal transport and lamB induction coincided with increased endogenous maltotriose (inducer) concentrations during growth on glucose. Hence regulation of glycoporin and the maltose-transport system is not a starvation- or stationary-phase response but facilitates the adaptation of Escherichia coli to low-nutrient environments through endoinduction.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Bacterial Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Cyclic AMP, http://linkedlifedata.com/resource/pubmed/chemical/DNA-Binding Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Escherichia coli Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Glucose, http://linkedlifedata.com/resource/pubmed/chemical/MalT protein, E coli, http://linkedlifedata.com/resource/pubmed/chemical/Maltose, http://linkedlifedata.com/resource/pubmed/chemical/Sigma Factor, http://linkedlifedata.com/resource/pubmed/chemical/Transcription Factors, http://linkedlifedata.com/resource/pubmed/chemical/Trisaccharides, http://linkedlifedata.com/resource/pubmed/chemical/maltotriose, http://linkedlifedata.com/resource/pubmed/chemical/sigma factor KatF protein, Bacteria
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
16
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
121-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Differential expression of mal genes under cAMP and endogenous inducer control in nutrient-stressed Escherichia coli.
pubmed:affiliation
Department of Microbiology G08, University of Sydney, New South Wales, Australia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't