Proteomic identification of glucocorticoid receptor interacting proteins
2006 (English)In: Proteomics, ISSN 1615-9853, Vol. 6, no 10, 3114-26 p.Article in journal (Refereed) Published
The glucocorticoid receptor (GR) acts as a ligand dependent transcription factor but can also cross talk with other signaling pathways via protein-protein interactions. In this paper we describe methods to study novel cytosolic GR interacting proteins, using mAb based immunoaffinity chromatography of GR from rat liver cytosol. Co-purifying proteins were identified by 2-DE in combination with MALDI-TOF-MS. Non-liganded/non-activated and in vitro liganded/activated GR, respectively, co-purifies with specific sets of proteins. Of these 34 were conclusively identified, seven have previously been reported to be part of the GR-complex, revealing 27 new possible interacting candidates for the GR-complex. Of the novel GR interacting proteins the major vault protein, TATA binding interacting protein 49a and glycoprotein PP63 were of special interest. Furthermore, using 2-D DIGE we show that the set of proteins interacting with non-liganded GR is distinctly different in protein amount compared to the proteins found with liganded/activated GR. This suggests the presence of different GR complexes in the cell, which was further substantiated by the finding of several separate GR native protein complexes, "GR-receptosomes", using blue native gel electrophoresis. Our findings suggest the existence of several new mechanisms for GR signaling and regulation.
Place, publisher, year, edition, pages
2006. Vol. 6, no 10, 3114-26 p.
Animals, Antibodies; Monoclonal, Cell Line; Tumor, Chromatography; Affinity, Cytosol/metabolism, Electrophoresis; Gel; Two-Dimensional, Electrophoresis; Polyacrylamide Gel, Immunoblotting, Ligands, Liver/metabolism, Protein Interaction Mapping, Proteome/*metabolism, Rats, Receptors; Glucocorticoid/agonists/*metabolism, Spectrometry; Mass; Matrix-Assisted Laser Desorption-Ionization
IdentifiersURN: urn:nbn:se:umu:diva-11756PubMedID: 16619302OAI: oai:DiVA.org:umu-11756DiVA: diva2:151427