Linked Life Data

1646987

Source:http://linkedlifedata.com/resource/pubmed/id/1646987

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1991-7-22
pubmed:abstractText
The epidermal growth factor receptor (EGF-R) C-terminus contains three conserved tyrosines (Y-1068, Y-1148, Y-1173) which are phosphorylated upon EGF activation. To clarify the functional role of these tyrosines, each has been mutated to phenylalanine and studied as single, double and triple mutants in the full length receptor. EGF-dependent transforming ability of the single point mutants is similar to that of the wild type, while that of double mutants is decreased and an even lower activity is present in the triple mutant. In each bioassay, including EGF-dependent focal transformation, growth in agar and growth in low serum, mutant receptors display a similar hierarchy of activity. The lower activity is intrinsic in the mutants since they are expressed at similar level as the wild type and bind EGF with similar affinity. Deletion mutants lacking the last 19 or 63 amino acids (Velu et al., 1989a) show a similar decline in biological activity when compared to the corresponding point mutants, although the reduction is more pronounced than with the point mutants. Deletion of the last 123 aa, which removes all three tyrosines (Dc123), results in a receptor that is almost inactive biologically. The EGF-R kinase activity is affected by tyrosine substitution since in vitro phosphorylation of exogenous substrates is reduced in the double and triple mutants. Autophosphorylation, in vivo and in vitro, is also reduced, but not totally abolished in the triple point mutant and Dc123 indicating the existence of other autophosphorylation sites. A new site of autophosphorylation is found in the Dc123 mutant. We conclude, therefore, that the tyrosines at the extreme C-terminus positively regulate the biological and transforming activity of the EGF-R, probably via autophosphorylation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0950-9232
pubmed:author
pubmed:issnType
Print
pubmed:volume
6
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
825-32
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
The biological activity of the human epidermal growth factor receptor is positively regulated by its C-terminal tyrosines.
pubmed:affiliation
Microbiology Institute, University of Copenhagen, Denmark.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't