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Involvement of the 90-kDa heat shock protein (Hsp-90) in CB2 cannabinoid receptor-mediated cell migration: a new role of Hsp-90 in migration signaling of a G protein-coupled receptor.
Mol Pharmacol 2007; 72(5):1289-300MP

Abstract

The endocannabinoid 2-arachidonoylglycerol (2-AG) enhances cell migration through the CB2 cannabinoid receptor. In this study, using an immunoprecipitation and mass spectrometry-based proteomic approach, we first identified the 90-kDa heat shock protein (Hsp90), a chaperone protein with novel signaling functions, as a CB2-interacting protein. The CB2/Hsp90 interaction was confirmed in human embryonic kidney 293 cells expressing transfected CB2 and in differentiated HL-60 cells expressing endogenous CB2, by coimmunoprecipitation and Western blot experiments, as well as by treatment with geldanamycin (GA), a specific Hsp90 inhibitor. Disruption of the CB2/Hsp90 interaction by treatment with GA or reducing Hsp90 levels with specific short interfering RNAs markedly inhibited 2-AG-induced cell migration, demonstrating that Hsp90 is crucial for 2-AG-induced cell migration. 2-AG treatment resulted in a CB2-mediated stimulation of Rac1 activity, and treatment with GA blocked 2AG-induced activation of Rac1. It is noteworthy that expression of the dominant-negative form of Rac1 reduced 2-AG-induced cell migration. These data demonstrate that 2-AG-induced activation of Rac1 is essential for 2-AG-induced cell migration, and the CB2/Hsp90 interaction is needed for 2-AG-induced activation of Rac1. Furthermore, 2-AG-induced Rac1 activation was sensitive to pertussis toxin treatment, hence involving G(i) proteins. In addition, treatment with GA significantly inhibited the CB2/Galpha(i2) interaction. As a whole, our data indicate that Hsp90 may serve as scaffold to keep the CB2 receptor and its signaling components, including Galpha(i2), in proximity, thus facilitating CB2-mediated signaling to cell migration through the G(i)-Rac1 pathway. By demonstrating that Hsp90 is essential for CB2-mediated signaling to cell migration, this study reveals a novel role of Hsp90 in the signaling events mediated by a G protein-coupled receptor.

Authors+Show Affiliations

Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY 40292, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, N.I.H., Extramural

Language

eng

PubMed ID

17698952

Citation

He, Fang, et al. "Involvement of the 90-kDa Heat Shock Protein (Hsp-90) in CB2 Cannabinoid Receptor-mediated Cell Migration: a New Role of Hsp-90 in Migration Signaling of a G Protein-coupled Receptor." Molecular Pharmacology, vol. 72, no. 5, 2007, pp. 1289-300.
He F, Qiao ZH, Cai J, et al. Involvement of the 90-kDa heat shock protein (Hsp-90) in CB2 cannabinoid receptor-mediated cell migration: a new role of Hsp-90 in migration signaling of a G protein-coupled receptor. Mol Pharmacol. 2007;72(5):1289-300.
He, F., Qiao, Z. H., Cai, J., Pierce, W., He, D. C., & Song, Z. H. (2007). Involvement of the 90-kDa heat shock protein (Hsp-90) in CB2 cannabinoid receptor-mediated cell migration: a new role of Hsp-90 in migration signaling of a G protein-coupled receptor. Molecular Pharmacology, 72(5), pp. 1289-300.
He F, et al. Involvement of the 90-kDa Heat Shock Protein (Hsp-90) in CB2 Cannabinoid Receptor-mediated Cell Migration: a New Role of Hsp-90 in Migration Signaling of a G Protein-coupled Receptor. Mol Pharmacol. 2007;72(5):1289-300. PubMed PMID: 17698952.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Involvement of the 90-kDa heat shock protein (Hsp-90) in CB2 cannabinoid receptor-mediated cell migration: a new role of Hsp-90 in migration signaling of a G protein-coupled receptor. AU - He,Fang, AU - Qiao,Zhuan-Hong, AU - Cai,Jian, AU - Pierce,William, AU - He,Da-Cheng, AU - Song,Zhao-Hui, Y1 - 2007/08/14/ PY - 2007/8/19/pubmed PY - 2007/12/14/medline PY - 2007/8/19/entrez SP - 1289 EP - 300 JF - Molecular pharmacology JO - Mol. Pharmacol. VL - 72 IS - 5 N2 - The endocannabinoid 2-arachidonoylglycerol (2-AG) enhances cell migration through the CB2 cannabinoid receptor. In this study, using an immunoprecipitation and mass spectrometry-based proteomic approach, we first identified the 90-kDa heat shock protein (Hsp90), a chaperone protein with novel signaling functions, as a CB2-interacting protein. The CB2/Hsp90 interaction was confirmed in human embryonic kidney 293 cells expressing transfected CB2 and in differentiated HL-60 cells expressing endogenous CB2, by coimmunoprecipitation and Western blot experiments, as well as by treatment with geldanamycin (GA), a specific Hsp90 inhibitor. Disruption of the CB2/Hsp90 interaction by treatment with GA or reducing Hsp90 levels with specific short interfering RNAs markedly inhibited 2-AG-induced cell migration, demonstrating that Hsp90 is crucial for 2-AG-induced cell migration. 2-AG treatment resulted in a CB2-mediated stimulation of Rac1 activity, and treatment with GA blocked 2AG-induced activation of Rac1. It is noteworthy that expression of the dominant-negative form of Rac1 reduced 2-AG-induced cell migration. These data demonstrate that 2-AG-induced activation of Rac1 is essential for 2-AG-induced cell migration, and the CB2/Hsp90 interaction is needed for 2-AG-induced activation of Rac1. Furthermore, 2-AG-induced Rac1 activation was sensitive to pertussis toxin treatment, hence involving G(i) proteins. In addition, treatment with GA significantly inhibited the CB2/Galpha(i2) interaction. As a whole, our data indicate that Hsp90 may serve as scaffold to keep the CB2 receptor and its signaling components, including Galpha(i2), in proximity, thus facilitating CB2-mediated signaling to cell migration through the G(i)-Rac1 pathway. By demonstrating that Hsp90 is essential for CB2-mediated signaling to cell migration, this study reveals a novel role of Hsp90 in the signaling events mediated by a G protein-coupled receptor. SN - 0026-895X UR - https://www.unboundmedicine.com/medline/citation/17698952/Involvement_of_the_90_kDa_heat_shock_protein__Hsp_90__in_CB2_cannabinoid_receptor_mediated_cell_migration:_a_new_role_of_Hsp_90_in_migration_signaling_of_a_G_protein_coupled_receptor_ L2 - http://molpharm.aspetjournals.org/cgi/pmidlookup?view=long&pmid=17698952 DB - PRIME DP - Unbound Medicine ER -