Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2002-12-9
pubmed:abstractText
The regulation of formation of the single intracellular beta-galactosidase activity of Aspergillus nidulans was investigated. beta-Galactosidase was not formed during growth on glucose or glycerol, but was rapidly induced during growth on lactose or D-galactose. L-Arabinose, and -- with lower efficacy -- D-xylose also induced beta-galactosidase activity. Addition of glucose to cultures growing on lactose led to a rapid decrease in beta-galactosidase activity. In contrast, in cultures growing on D-galactose, addition of glucose decreased the activity of beta-galactosidase only slightly. Glucose inhibited the uptake of lactose, but not of D-galactose, and required the carbon catabolite repressor CreA for this. In addition, CreA also repressed the formation of basal levels of beta-galactosidase and partially interfered with the induction of beta-galactosidase by D-galactose, L-arabinose, and D-xylose. D-Galactose phosphorylation was not necessary for beta-galactosidase induction, since induction by D-galactose occurred in an A. nidulans mutant defective in galactose kinase, and by the non-metabolizable D-galactose analogue fucose in the wild-type strain. Interestingly, a mutant in galactose-1-phosphate uridylyl transferase produced beta-galactosidase at a low, constitutive level even on glucose and glycerol and was no longer inducible by D-galactose, whereas it was still inducible by L-arabinose. We conclude that biosynthesis of the intracellular beta-galactosidase of A. nidulans is regulated by CreA, partially repressed by galactose-1-phosphate uridylyl transferase, and induced by D-galactose and L-arabinose in independent ways.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0302-8933
pubmed:author
pubmed:issnType
Print
pubmed:volume
179
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7-14
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Regulation of formation of the intracellular beta-galactosidase activity of Aspergillus nidulans.
pubmed:affiliation
Department of Microbiology and Biotechnology, Faculty of Science, University of Debrecen, 4010, P.O.Box 63, Debrecen, Hungary.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't