Phosphatidylinositol 3,4,5-trisphosphate triggers platelet aggregation by activating Ca2+ influx

被引:31
作者
Lu, PJ [1 ]
Hsu, AL [1 ]
Wang, DS [1 ]
Chen, CS [1 ]
机构
[1] Univ Kentucky, Coll Pharm, Div Med Chem & Pharmaceut, Lexington, KY 40506 USA
关键词
D O I
10.1021/bi980163o
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Exogenous phosphatidylinositol 3,4,5-trisphosphate [PtdIns(3,4,5)P-3] stimulates the aggregation of washed rabbit platelets in a Ca2+- and dose-dependent manner. This aggregation is reversible at low PtdIns(3,4,5)P3 levels, but becomes irreversible when the concentration exceeds a threshold of about 20 mu M. Other D-3 and D-4 phosphoinositides examined, including phosphatidylinositol 3,4-bisphosphate [PtdIns(3,4)P-2], phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P-2], and phosphatidylinositol 3-monophosphate [PtdIns(3)P], fail to exert appreciable platelet activation at comparable concentrations. In addition, PtdIns(3,4,5)P-3 can reverse the inhibitory effect of wortmannin on thrombin-induced platelet aggregation. Taken together with the observation that PtdIns(3,4,5)P-3 is readily incorporated into cell membranes, these findings reaffirm the second messenger role of PtdIns(3,4,5)P-3 in thrombin receptor activation. The existence of a PtdIns(3,4,5)P-3-dependent Ca2+ entry system on platelet membranes is supported by the partial inhibition of thrombin-induced Ca2+ influx by wortmannin. Evidence suggests that this system differs from receptor-operated nonselective Ca2+ channels.; However, the mechanism by which PtdIns(3,4,5)P-3 facilitates Ca2+ entry remains unclear. Although PtdIns(3,4,5)P-3 has been known to stimulate phospholipase C-gamma (PLC-gamma), internal Ca2+ mobilization does not play a significant role in the cytosolic Ca2+ increase in response to PtdIns(3,4,5)P-3 stimulation. Collectively, these data provide a putative link between PtdIns(3,4,5)P-3 and Ca2+ signaling, which may, in part, account for the regulatory function of PtdIns(3,4,5)P-3 during platelet aggregation. Moreover, this study bears out the notion that individual PI 3-kinase lipid products play distinct roles in the regulation of cellular functions.
引用
收藏
页码:9776 / 9783
页数:8
相关论文
共 46 条
[1]  
ANGER KR, 1989, CELL, V57, P167
[2]   STIMULATION OF NONSELECTIVE CATION CHANNELS PROVIDING CA2+ INFLUX INTO PLATELETS BY PLATELET-ACTIVATING-FACTOR AND OTHER AGGREGATION INDUCERS [J].
AVDONIN, PV ;
CHEGLAKOV, IB ;
TKACHUK, VA .
EUROPEAN JOURNAL OF BIOCHEMISTRY, 1991, 198 (01) :267-273
[3]   NI2+ IMPAIRS THROMBIN-INDUCED SIGNAL-TRANSDUCTION BY ACTING ON THE AGONIST AND OR RECEPTOR IN HUMAN PLATELETS [J].
AZULA, FJ ;
ALONSO, R ;
MARINO, A ;
TRUEBA, M ;
MACARULLA, JM .
AMERICAN JOURNAL OF PHYSIOLOGY, 1993, 265 (06) :C1681-C1688
[4]   Activation of phospholipase C-γ by phosphatidylinositol 3,4,5-trisphosphate [J].
Bae, YS ;
Cantley, LG ;
Chen, CS ;
Kim, SR ;
Kwon, KS ;
Rhee, SG .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1998, 273 (08) :4465-4469
[5]  
Baenziger N L, 1974, Methods Enzymol, V31, P149
[6]   A novel integrin-activated pathway forms PKB/Akt-stimulatory phosphatidylinositol 3,4-bisphosphate via phosphatidylinositol 3-phosphate in platelets [J].
Banfic, H ;
Tang, XW ;
Batty, IH ;
Downes, CP ;
Chen, CS ;
Rittenhouse, SE .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1998, 273 (01) :13-16
[7]  
CATER AN, 1994, BIOCHEM J, V301, P415
[8]   SPECIFIC BINDING-SITES FOR INOSITOL 1,3,4,5-TETRAKISPHOSPHATE ARE LOCATED PREDOMINANTLY IN THE PLASMA-MEMBRANES OF HUMAN PLATELETS [J].
CULLEN, PJ ;
PATEL, Y ;
KAKKAR, VV ;
IRVINE, RF ;
AUTHI, KS .
BIOCHEMICAL JOURNAL, 1994, 298 :739-742
[9]   PURIFICATION AND CHARACTERIZATION OF AN INS(1,3,4,5)P-4 BINDING-PROTEIN FROM PIG PLATELETS - POSSIBLE IDENTIFICATION OF A NOVEL NONNEURONAL INS(1,3,4,5)P-4 RECEPTOR [J].
CULLEN, PJ ;
DAWSON, AP ;
IRVINE, RF .
BIOCHEMICAL JOURNAL, 1995, 305 :139-143
[10]   IDENTIFICATION OF A SPECIFIC INS(1,3,4,5)P-4-BINDING PROTEIN AS A MEMBER OF THE GAP1 FAMILY [J].
CULLEN, PJ ;
HSUAN, JJ ;
TRUONG, O ;
LETCHER, AJ ;
JACKSON, TR ;
DAWSON, AP ;
IRVINE, RF .
NATURE, 1995, 376 (6540) :527-530