Linked Life Data

2676720

Source:http://linkedlifedata.com/resource/pubmed/id/2676720

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1989-11-22
pubmed:abstractText
In yeast, galactose triggers a rapid GAL4-dependent induction of galactose/melibiose regulon (GAL/MEL) gene transcription, and glucose represses this activation. We discovered that alterations in the physical state of the GAL4 protein correlate with activation and repression of the GAL/MEL genes. Using Western immunoblot assay, we observe two electrophoretic forms of GAL4 protein-GAL4I and GAL4II-in noninduced cells. In the absence of glucose, the addition of galactose to such cells results in the rapid appearance of a third and slower-migrating form, GAL4III, which differs from at least GAL4I by phosphorylation. GAL80-deletion cells that constitutively transcribe galactose-responsive genes due to the lack of the GAL80 protein, an antagonist of the GAL4 protein, exhibit GAL4III without galactose addition. Addition of glucose, which results in rapid repression of galactose gene transcription, triggers a rapid elimination of GAL4III and an increase in GAL4II. Cycloheximide experiments provide evidence that the galactose- and glucose-triggered GAL4 protein mobility shifts are due to post-translational modification. GAL4III is labeled with [32P]phosphate in vivo; in vivo 35S-labeled GAL4III could be converted by phosphatase treatment in vitro to GAL4I. We present a model proposing that phosphorylation state changes in the GAL4 protein are key to modulating its activity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0890-9369
pubmed:author
pubmed:issnType
Print
pubmed:volume
3
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1157-65
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Regulated phosphorylation and dephosphorylation of GAL4, a transcriptional activator.
pubmed:affiliation
Department of Biological Chemistry, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.