Linked Life Data

15994331

Source:http://linkedlifedata.com/resource/pubmed/id/15994331

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
34
pubmed:dateCreated
2005-8-22
pubmed:abstractText
The epidermal growth factor receptor (EGFR) is a member of the erbB tyrosine kinase family of receptors. For many years it has been believed that receptor activation occurs via a monomer-dimer transition that is associated with a conformational change to activate the kinase. However, little is known about the quaternary state of the receptor at normal levels of expression (<10(5) receptors/cell). We employed multidimensional microscopy techniques to gain insight into the state of association of the human EGFR, in the absence and presence of ligand, on the surface of intact BaF/3 cells (50,000 receptors/cell). Image correlation microscopy of an EGFR-enhanced green fluorescent protein chimera was used to establish an average degree of aggregation on the submicron scale of 2.2 receptors/cluster in the absence of ligand increasing to 3.7 receptors/cluster in the presence of ligand. Energy transfer measurements between mixtures of fluorescein isothiocyanate-EGF and Alexa 555-EGF were performed using fluorescence lifetime imaging microscopy as a function of the donor: acceptor labeling ratio to gain insight into the spatial disposition of EGFR ligand binding sites on the nanometer scale. In the context of a two-state Förster resonance energy transfer (FRET)/non-FRET model, the data are consistent with a minimum transfer efficiency of 75% in the FRET population. The microscopy data are related to biophysical data on the EGFR in the A431 cell line and the three-dimensional structure of the ligated EGFR extracellular domain. In the context of a monomer-dimer-oligomer model, the biophysical data are consistent with a significant fraction of ligated EGFR tetramers comprising two dimers juxtaposed in a side-by-side (or slightly staggered) arrangement. Our data are consistent with a specific higher order association of the ligand-bound EGFR on the nanometer scale and indicate the existence of distinct signaling entities beyond the level of the EGFR dimer which could play an important role in receptor transactivation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
280
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
30392-9
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:15994331-Animals, pubmed-meshheading:15994331-Cell Line, pubmed-meshheading:15994331-Cell Membrane, pubmed-meshheading:15994331-Chromatography, High Pressure Liquid, pubmed-meshheading:15994331-Culture Media, Serum-Free, pubmed-meshheading:15994331-Dimerization, pubmed-meshheading:15994331-Dose-Response Relationship, Drug, pubmed-meshheading:15994331-Fluorescein-5-isothiocyanate, pubmed-meshheading:15994331-Fluorescence Resonance Energy Transfer, pubmed-meshheading:15994331-Green Fluorescent Proteins, pubmed-meshheading:15994331-Kinetics, pubmed-meshheading:15994331-Ligands, pubmed-meshheading:15994331-Mice, pubmed-meshheading:15994331-Microscopy, pubmed-meshheading:15994331-Microscopy, Confocal, pubmed-meshheading:15994331-Microscopy, Fluorescence, pubmed-meshheading:15994331-Models, Biological, pubmed-meshheading:15994331-Phosphorylation, pubmed-meshheading:15994331-Protein Structure, Tertiary, pubmed-meshheading:15994331-Receptor, Epidermal Growth Factor, pubmed-meshheading:15994331-Recombinant Fusion Proteins, pubmed-meshheading:15994331-Transcriptional Activation, pubmed-meshheading:15994331-Tyrosine
pubmed:year
2005
pubmed:articleTitle
Ligand-induced dimer-tetramer transition during the activation of the cell surface epidermal growth factor receptor-A multidimensional microscopy analysis.
pubmed:affiliation
Ludwig Institute for Cancer Research, Melbourne Tumour Biology Branch, Royal Melbourne Hospital, Victoria 3050, Australia. andrew.clayton@ludwig.edu.au
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't