“Thrombin” receptor-directed ligand accounts for activation by thrombin of platelet phospholipase C and accumulation of 3-phosphorylated phosphoinositides.

Huang, R S; Sorisky, Alexander; Church, William R.; Simons, Elizabeth R.; Rittenhouse, Susan E.

doi:10.1016/s0021-9258(18)55079-1

Cited by 111 publications

(11 citation statements)

References 22 publications

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“…In contrast, the PtdIns(3,4,5)P3 signal (Fig. 2 A, inset) appeared to be more rapid than PtdIns(3,4)P2 synthesis, as previously reported (24,38). Thus, the accumulation of Ptd-Ins(3,4)P2 but not of PtdIns(3,4,5)P3 temporally correlated with the translocation of PtdIns 3-kinase to the cytoskeleton.…”

Section: Ptdlns(34)pz But Not Ptdins(345)pj Synthesis Parallels Translocation Of Activated Ptdlns 3-kinase To the Cytoskeletonsupporting

confidence: 81%

“…Interestingly, Ptdlns(3,4)P2 but not PtdIns(3,4,5)P3 synthesis paralleled the translocation of both p85ot and Ptdlns 3-kinase activity to the cytoskeleton, strongly suggesting a relationship between these two events. In thrombin-stimulated platelets, PtdIns(3,4,5)P3 is produced very rapidly, whereas Ptdlns(3,4)P2 accumulates at a later stage (24,38). Although Ptdlns(3,4)P2 has been shown to be a degradation product of Ptdlns (3,4,5)P3 in neutrophils, Sorisky et al (38) have demonstrated that the production of these two phospholipids is regulated differ-ently in thrombin-stimulated platelets.…”

Section: Discussionmentioning

confidence: 99%

“…T HE accumulation of phosphatidylinositol 3,4-bisphosphate (Ptdlns(3,4)P2) m and Ptdlns (3,4,5)P3 in thrombin-stimulated human platelets is now well established (16,24,38,41) and seems to be regulated differently (38). However, the exact mechanism of activation of phosphoinositide 3-kinase (Ptdlns 3-kinase) in these ceils is still obscure.…”

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confidence: 99%

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Integrin-dependent translocation of phosphoinositide 3-kinase to the cytoskeleton of thrombin-activated platelets involves specific interactions of p85 alpha with actin filaments and focal adhesion kinase.

Guinebault

Payrastre

Racaud‐Sultan

et al. 1995

The Journal of Cell Biology

219

135

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Abstract. Thrombin-induced accumulation of phosphatidylinositol 3,4-bisphosphate (Ptdlns(3,4)P2) but not of PtdIns(3,4,5,)P3 is strongly correlated with the relocation to the cytoskeleton of 29 % of the p85o~ regulatory subunit of phosphoinositide 3-kinase (Ptdlns 3-kinase) and is accompanied by a significant increase in Ptdlns 3-kinase activity in this subcellular fraction. Actually, Ptdlns(3,4)P2 accumulation and Ptdlns 3-kinase, pp60 ~-s'~, and p125 eA~ translocations as well as aggregation were concomitant events occurring with a distinct lag after actin polymerization. The accumulation of Ptdlns(3,4)P2 and the relocalization of Ptdlns 3-kinase to the cytoskeleton were both dependent on tyrosine phosphorylation, integrin signaling, and aggregation. Furthermore, although p85o~ was detected in anti-phosphotyrosine immunoprecipitates obtained from the cytoskeleton of thrombin-activated platelets, we failed to demonstrate tyrosine phosphorylation of cytoskeletal p85a. Tyrphostin treatment clearly reduced its presence in this subcellular fraction, suggesting a physical interaction of p85et with a phosphotyrosyl protein. These data led us to investigate the proteins that are able to interact with Ptdlns 3-kinase in the cytoskeleton. We found an association of this enzyme with actin filaments: this interaction was spontaneously restored after one cycle of actin depolymerization-repolymerization in vitro. This association with F-actin appeared to be at least partly indirect, since we demonstrated a thrombin-dependent interaction of p85tx with a proline-rich sequence of the tyrosine-phosphorylated cytoskeletal focal adhesion kinase, p125 rAK. In addition, we show that Ptdlns 3-kinase is significantly activated by the p125 rAK proline-rich sequence binding to the src homology 3 domain of p85a subunit. This interaction may represent a new mechanism for Ptdlns 3-kinase activation at very specific areas of the cell and indicates that the focal contact-like areas linked to the actin filaments play a critical role in signaling events that occur upon ligand engagement of o~ro/~3 integrin and platelet aggregation evoked by thrombin.T HE accumulation of phosphatidylinositol 3,4-bisphosphate (Ptdlns(3,4)P2) m and Ptdlns(3,4,5)P3 in thrombin-stimulated human platelets is now well established (16,24,38,41) and seems to be regulated differently (38). However, the exact mechanism of activation of phosphoinositide 3-kinase (Ptdlns 3-kinase) in these ceils is still obscure.

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Section: Ptdlns(34)pz But Not Ptdins(345)pj Synthesis Parallels Translocation Of Activated Ptdlns 3-kinase To the Cytoskeletonsupporting

confidence: 81%

Section: Discussionmentioning

confidence: 99%

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Integrin-dependent translocation of phosphoinositide 3-kinase to the cytoskeleton of thrombin-activated platelets involves specific interactions of p85 alpha with actin filaments and focal adhesion kinase.

Guinebault

Payrastre

Racaud‐Sultan

et al. 1995

The Journal of Cell Biology

219

135

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“…Evidence for this proteolytic mechanism of activation is supported by the findings that a synthetic peptide corresponding to the N-terminal sequence of the cleaved receptor (residues Ser-42 to Phe-55) is able to stimulate aggregation of human platelets and Ca2+ release in Xenopus oocytes expressing the cloned human receptor [1]. Further, this 14-amino-acid peptide (SFLLRNPNDKYEPF) has been found to trigger several intracellular signalling events in human platelets including phospholipase C and phosphatidylinositol 3-kinase activation [3], adenyl cyclase inhibition and phosphorylation of proteins on tyrosine residues [4,5] Activation of non-platelet cellular responses also appears to be mediated by the cloned receptor, or a similar subtype. Peptides derived from the human or hamster a-thrombin receptor sequence are able to mimic a-thrombin action on G-proteincoupled effectors in fibroblasts [6] and HEL cells [7], to elevate intracellular Ca2+ and stimulate prostacyclin production in human endothelial cells [8], and to cause neurite retraction in neuronal cells [9].…”

Section: Introductionmentioning

confidence: 90%

Structure-activity analysis of synthetic α-thrombin-receptor-activating peptides

Obberghen-Schilling

Rasmussen

Vouret‐Craviari

et al. 1993

Biochemical Journal

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alpha-Thrombin stimulates G-protein-coupled effectors leading to secretion and aggregation in human platelets, and to a mitogenic response in CCL39 hamster fibroblasts. alpha-Thrombin receptors can be activated by synthetic peptides corresponding to the receptor sequence starting with serine-42, at the proposed cleavage site. We have previously determined that the agonist domain of receptor-activating peptides resides within the five N-terminal residues [Vouret-Craviari, Van Obberghen-Schilling, Rasmussen, Pavirani, Lecocq and Pouysségur (1992) Mol. Biol. Cell. 3, 95-102], although the 7-residue peptide (SFFLRNP) corresponding to the hamster alpha-thrombin receptor was 10 times more potent than the 5-residue peptide for activation of human platelets. In the present study we have analysed the role of individual amino acids in receptor activation by using a series of modified hexa- or hepta-peptides derived from the human alpha-thrombin-receptor sequence. Cellular events examined here include phospholipase C activation, adenylyl cyclase inhibition and DNA synthesis stimulation in non-transformed CCL39 fibroblasts and a tumorigenic variant of that line (A71 cells). Modification of the peptide sequence had similar functional consequence for each of the assays described, indicating that either a unique receptor or pharmacologically indistinguishable receptor subtypes activate distinct G-protein signalling pathways. Furthermore, we found that: (1) the N-terminal serine can be replaced by small or intermediately sized amino acids (+/- hydroxyl groups) without loss of activity. However, its replacement by an aromatic side-chain or omission of the N-terminal amino group severely reduces activity. (2) An aromatic side-chain on the penultimate N-terminal residue appears to play a critical role since phenylalanine in this position can be substituted by tyrosine without complete loss of activity whereas an alanine in its place is not tolerated. (3) Deletion of the first, second or third N-terminal residue leads to a loss of activity, suggesting that a defined spacing of more than one structural component may be important for ligand-receptor interaction. Finally, we did not observe an antagonistic effect of the inactive peptides on phospholipase C activation or DNA synthesis induced by alpha-thrombin (1 nM) or SFLLRNP (3 microM).

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“…The remaining shortened extracellular portion after cleavage contains a newly exposed NH2 terminus that binds to as yet an undefined region on the thrombin receptor, and functions as a "tethered ligand" to activate the receptor (27,36). Synthetic peptides corresponding to the exposed NH2 terminus (i.e., SFLLRNPNDKYEPF) (TRP-14) elicit cellular responses characteristic of native thrombin (e.g., platelet aggregation [15,29,36], increase in [Ca2+]~ in endothelial cells [26], activation of PLC [15,35], and activation of neutrophil adhesion via P-selectin expression on endothelial cells [31]).…”

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confidence: 99%

Thrombin receptor peptide inhibits thrombin-induced increase in endothelial permeability by receptor desensitization.

Lum

Andersen

Siflinger-Birnboim

et al. 1993

The Journal of Cell Biology

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Abstract. Thrombin, a potent activator of cellular responses, proteolytically cleaves, and thereby activates its receptor. In the present study, we compared the effects of the thrombin receptor 14-amino acid peptide (TRP-14; SFLLRNPNDKYEPF), which comprises the NH2 terminus after cleavage of the thrombin receptor, and of the native ot-thrombin on endothelial monolayer permeability. Addition of TRP-14 (1-200 #M) to bovine pulmonary artery endothelial cells increased [Ca2+]i in a dose-dependent manner. The peak increase in [Ca2+]i in response to 100 #M TRP-14 or 0.1 #M ot-thrombin was similar (i.e., 931 + 74 nM and 1032 + 80 nM, respectively), which was followed by a slow decrease with tirE values of 0.73 and 0.61 min, respectively. Extracellular Ca z+ chelation with 5 mM EGTA abolished the sustained increases in [Ca~+]i induced by either TRP-14 or ol-thrombin, ot-thrombin (0.1 /zM) increased transendothelial [~25I]albumin permeability, whereas TRP-14 (1-100 #M) had no effect. Coincubation of 100 #M TRP-14 with 1 #M DIP-athrombin also did not increase permeability over control values. Stimulation of BPAEC with 0

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“Thrombin” receptor-directed ligand accounts for activation by thrombin of platelet phospholipase C and accumulation of 3-phosphorylated phosphoinositides.

Cited by 111 publications

References 22 publications

Integrin-dependent translocation of phosphoinositide 3-kinase to the cytoskeleton of thrombin-activated platelets involves specific interactions of p85 alpha with actin filaments and focal adhesion kinase.

Integrin-dependent translocation of phosphoinositide 3-kinase to the cytoskeleton of thrombin-activated platelets involves specific interactions of p85 alpha with actin filaments and focal adhesion kinase.

Structure-activity analysis of synthetic α-thrombin-receptor-activating peptides

Thrombin receptor peptide inhibits thrombin-induced increase in endothelial permeability by receptor desensitization.

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