@article {827,
	title = {Thrombin receptor signaling to cytoskeleton requires Hsp90.},
	journal = {J Biol Chem},
	volume = {276},
	year = {2001},
	month = {2001 Aug 31},
	pages = {32642-7},
	abstract = {<p>Thrombin is a serine protease that evokes various cellular responses involved in injury and repair of the nervous system through the activation of protease-activated receptor-1 (PAR-1). Signals that modulate cell morphology precede most PAR-1 effects, but the initial signal transduction molecules are not known. Using the yeast two-hybrid system, we identified Hsp90, a chaperone with known signaling properties, as a binding partner of PAR-1. The interaction was confirmed by glutathione S-transferase pull-down, overlay, and co-immunoprecipitation assays. Morphological assays in mouse astrocytes were carried out to evaluate the importance of Hsp90 during cytoskeletal signaling. Reducing Hsp90 levels by antisense treatment or disruption of the Hsp90.PAR-1 complex by the Hsp90-specific drug geldanamycin attenuated thrombin-mediated astrocyte shape changes. Furthermore, overexpression of the PAR-1 cytoplasmic tail abrogated thrombin-induced cytoskeletal changes in neuronal cells. Treatment with geldanamycin specifically inhibited activation of RhoA without affecting thrombin-mediated intracellular calcium release, revealing the regulation of a distinct signaling pathway by Hsp90. Taken together, these studies demonstrate that Hsp90 may be essential for PAR-1-mediated signaling to the cytoskeleton.</p>},
	keywords = {Animals, Animals, Newborn, Astrocytes, Cells, Cultured, Cerebral Cortex, Cloning, Molecular, Cytoskeleton, HSP90 Heat-Shock Proteins, Humans, Neurons, Oligodeoxyribonucleotides, Antisense, Rats, Rats, Sprague-Dawley, Receptor, PAR-1, Receptors, Thrombin, Recombinant Fusion Proteins, rhoA GTP-Binding Protein, Saccharomyces cerevisiae, Signal Transduction, Thrombin},
	issn = {0021-9258},
	doi = {10.1074/jbc.M104212200},
	author = {Pai, K S and Mahajan, V B and Lau, A and Cunningham, D D}
}
@article {185,
	title = {Creatine kinase, an ATP-generating enzyme, is required for thrombin receptor signaling to the cytoskeleton.},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {97},
	year = {2000},
	month = {2000 Oct 24},
	pages = {12062-7},
	abstract = {<p>Thrombin orchestrates cellular events after injury to the vascular system and extravasation of blood into surrounding tissues. The pathophysiological response to thrombin is mediated by protease-activated receptor-1 (PAR-1), a seven-transmembrane G protein-coupled receptor expressed in the nervous system that is identical to the thrombin receptor in platelets, fibroblasts, and endothelial cells. Once activated by thrombin, PAR-1 induces rapid and dramatic changes in cell morphology, notably the retraction of growth cones, axons, and dendrites in neurons and processes in astrocytes. The signal is conveyed by a series of localized ATP-dependent reactions directed to the actin cytoskeleton. How cells meet the dynamic and localized energy demands during signal transmission is unknown. Using the yeast two-hybrid system, we identified an interaction between PAR-1 cytoplasmic tail and the brain isoform of creatine kinase, a key ATP-generating enzyme that regulates ATP within subcellular compartments. The interaction was confirmed in vitro and in vivo. Reducing creatine kinase levels or its ATP-generating potential inhibited PAR-1-mediated cellular shape changes as well as a PAR-1 signaling pathway involving the activation of RhoA, a small G protein that relays signals to the cytoskeleton. Thrombin-stimulated intracellular calcium release was not affected. Our results suggest that creatine kinase is bound to PAR-1 where it may be poised to provide bursts of site-specific high-energy phosphate necessary for efficient receptor signal transduction during cytoskeletal reorganization.</p>
},
	keywords = {Adenosine Triphosphate, Animals, Base Sequence, Calcium, Creatine Kinase, Cytoskeleton, Oligonucleotides, Antisense, Rats, Receptor, PAR-1, Receptors, Thrombin, Signal Transduction, Two-Hybrid System Techniques},
	author = {Mahajan, V B and Pai, K S and Lau, A and Cunningham, D D}
}
