Intermolecular relations between the glucocorticoid receptor, ZAP-70 kinase, and Hsp-90

D Bartis, F Boldizsár, K Kvell, M Szabó… - Biochemical and …, 2007 - Elsevier
D Bartis, F Boldizsár, K Kvell, M Szabó, L Pálinkás, P Németh, E Monostori, T Berki
Biochemical and biophysical research communications, 2007Elsevier
The glucocorticoid receptor (GR) participates in both genomic and non-genomic
glucocorticoid hormone (GC) actions by interacting with other cytoplasmic signalling
proteins. Previously, we have shown that high dose Dexamethasone (DX) treatment of
Jurkat cells causes tyrosine phosphorylation of ZAP-70 within 5min in a GR-dependent
manner. By using co-immunoprecipitation and confocal microscopy, here we demonstrate
that the liganded GR physically associates with ZAP-70, in addition to its phosphorylation …
The glucocorticoid receptor (GR) participates in both genomic and non-genomic glucocorticoid hormone (GC) actions by interacting with other cytoplasmic signalling proteins. Previously, we have shown that high dose Dexamethasone (DX) treatment of Jurkat cells causes tyrosine phosphorylation of ZAP-70 within 5min in a GR-dependent manner. By using co-immunoprecipitation and confocal microscopy, here we demonstrate that the liganded GR physically associates with ZAP-70, in addition to its phosphorylation changes. The association of the ligand-bound GR and ZAP-70 was also observed in HeLa cells transfected with ZAP-70, suggesting that this co-clustering is independent of lymphocyte specific factors. Furthermore, the ZAP-70 was found to also co-precipitate with Hsp-90 chaperone both in Jurkat and transgenic HeLa cells, independent of the presence of DX. These findings raise the possibility that ZAP-70 may serve as an important link between GC and TcR-induced signaling, thereby transmitting non-genomic GC action in T-cells.
Elsevier