TY - JOUR
T1 - The 27-kDa heat shock protein confers cytoprotective effects through a β2-adrenergic receptor agonist-initiated complex with β-arrestin
AU - Rojanathammanee, Lalida
AU - Harmon, Erin B.
AU - Grisanti, Laurel A.
AU - Govitrapong, Piyarat
AU - Ebadi, Manuchair
AU - Grove, Bryon D.
AU - Miyagi, Masaru
AU - Porter, James E.
PY - 2009/4
Y1 - 2009/4
N2 - Heat shock proteins represent an emerging model for the coordinated, multistep regulation of apoptotic signaling events. Although certain aspects of the biochemistry associated with heat shock protein cytoprotective effects are known, little information is found describing the regulation of heat shock protein responses to harmful stimuli. During screening for non-canonical (β adrenergic receptor signaling pathways in human urothelial cells, using mass spectroscopy techniques, an agonist-dependent interaction with β-arrestin and the 27-kDa heat shock protein was observed in vitro. Formation of this β-arrestin/Hsp27 complex in response to the selective β adrenergic receptor agonist isoproterenol, was subsequently confirmed in situ by immunofluorescent colocalization studies. Radioligand binding techniques characterized a homogeneous population of the β2 adrenergic receptor subtype expressed on these cells. Using terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling, immunoblot analysis and quantitation of caspase-3 activity to detect apoptosis, preincubation of these cells with isoproterenol was found to be sufficient for protection against programmed cell death initiated by staurosporine. RNA interference strategies confirmed the necessity for Hsp27 as well as both 3-arrestin isoforms to confer this cytoprotective consequence of (β adrenergic receptor activation in this cell model. As a result, these studies represent the first description of an agonist-dependent relationship between a small heat shock protein and β-arrestin to form a previously unknown antiapoptotic "signalosome."
AB - Heat shock proteins represent an emerging model for the coordinated, multistep regulation of apoptotic signaling events. Although certain aspects of the biochemistry associated with heat shock protein cytoprotective effects are known, little information is found describing the regulation of heat shock protein responses to harmful stimuli. During screening for non-canonical (β adrenergic receptor signaling pathways in human urothelial cells, using mass spectroscopy techniques, an agonist-dependent interaction with β-arrestin and the 27-kDa heat shock protein was observed in vitro. Formation of this β-arrestin/Hsp27 complex in response to the selective β adrenergic receptor agonist isoproterenol, was subsequently confirmed in situ by immunofluorescent colocalization studies. Radioligand binding techniques characterized a homogeneous population of the β2 adrenergic receptor subtype expressed on these cells. Using terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling, immunoblot analysis and quantitation of caspase-3 activity to detect apoptosis, preincubation of these cells with isoproterenol was found to be sufficient for protection against programmed cell death initiated by staurosporine. RNA interference strategies confirmed the necessity for Hsp27 as well as both 3-arrestin isoforms to confer this cytoprotective consequence of (β adrenergic receptor activation in this cell model. As a result, these studies represent the first description of an agonist-dependent relationship between a small heat shock protein and β-arrestin to form a previously unknown antiapoptotic "signalosome."
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U2 - 10.1124/mol.108.053397
DO - 10.1124/mol.108.053397
M3 - Article
C2 - 19176359
AN - SCOPUS:63849114816
SN - 0026-895X
VL - 75
SP - 855
EP - 865
JO - Molecular pharmacology
JF - Molecular pharmacology
IS - 4
ER -