Linked Life Data

10542233

Source:http://linkedlifedata.com/resource/pubmed/id/10542233

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
45
pubmed:dateCreated
1999-12-13
pubmed:abstractText
The O-GlcNAc transferase (OGT) is a unique nuclear and cytosolic glycosyltransferase that contains multiple tetratricopeptide repeats. We have begun to characterize the mechanisms regulating OGT using a combination of deletion analysis and kinetic studies. Here we show that the p110 subunit of the enzyme forms both homo- and heterotrimers that appear to have different binding affinities for UDP-GlcNAc. The multimerization domain of OGT lies within the tetratricopeptide repeat domain and is not necessary for activity. Kinetic analyses of the full-length trimer and the truncated monomer forms of OGT suggest that both forms function through a random bi-bi kinetic mechanism. Both the monomer and trimer have similar specific activities and similar K(m) values for peptide substrates. However, they differ in their binding affinities for UDP-GlcNAc, indicating that subunit interactions affect enzyme activity. The findings that recombinant OGT has three distinct K(m) values for UDP-GlcNAc and that UDP-GlcNAc concentrations modulates the affinity of OGT for peptides suggest that OGT is exquisitely regulated by the levels of UDP-GlcNAc within the nucleus and cytoplasm.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
32015-22
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Regulation of a cytosolic and nuclear O-GlcNAc transferase. Role of the tetratricopeptide repeats.
pubmed:affiliation
Department of Biological Chemistry, Johns Hopkins University, Baltimore, Maryland 21205, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't