Targeted gene inactivation reveals a functional role of calpain-1 in platelet spreading.
Targeted gene inactivation reveals a functional role of calpain-1 in platelet spreading.
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DOI：
10.1111/j.1538-7836.2012.04715.x
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发表时间：
2012-06
期刊：
影响因子：
--
通讯作者：
Chishti AH
中科院分区：
文献类型：
--
作者：
Kuchay SM;Wieschhaus AJ;Marinkovic M;Herman IM;Chishti AH
钙蛋白酶参与广泛的细胞功能，包括通过调节血小板中的细胞骨架修饰来维持止血。确定钙蛋白酶亚型在血小板扩散中的功能作用。来自calpain-1−/−小鼠的血小板在胶原蛋白和纤维蛋白原包被的表面上显示出增强的扩散，如免疫荧光、微分干涉对比（DIC）和扫描电子显微镜所示。用MDL（一种钙蛋白酶1/2的细胞渗透性抑制剂）处理小鼠血小板，导致扩散增加。PTP 1B介导的钙蛋白酶-1-/-血小板中酪氨酸去磷酸化的增强并不能完全解释增强的扩散，因为缺乏钙蛋白酶-1和PTP 1B的双敲除小鼠的血小板仅显示出部分的扩散表型拯救。在非粘附血小板中，RhoA和Rac 1的蛋白水解和GTdR活性在野生型（WT）和钙蛋白酶-1-/-血小板之间无法区分。相比之下，ECM粘附的钙蛋白酶-1-/-血小板在扩散开始时表现出更高的Rac 1活性，而RhoA在稍后的时间点更具活性。ECM粘附的钙蛋白酶-1 −/−血小板显示RhoA蛋白水平升高，但Rac 1和Cdc 42没有升高。重组RhoA的蛋白水解，而不是Rac 1和Cdc 42，表明RhoA是钙蛋白酶-1底物在体外。钙蛋白酶-1-/-小鼠血小板扩散表型的增强表明钙蛋白酶-1在止血中的新作用，并可能解释在钙蛋白酶-1-/-小鼠中观察到的正常出血时间。
Calpains are implicated in a wide range of cellular functions including the maintenance of hemostasis via the regulation of cytoskeletal modifications in platelets. Determine the functional role of calpain isoforms in platelet spreading. Platelets from calpain-1−/− mice show enhanced spreading on collagen-and fibrinogen-coated surfaces as revealed by immunofluorescence, differential interference contrast (DIC) and scanning electron microscopy. The treatment of mouse platelets with MDL, a cell permeable inhibitor of calpains 1/2, resulted in increased spreading. The PTP1B-mediated enhanced tyrosine dephosphorylation in calpain-1−/− platelets did not fully account for the enhanced spreading as platelets from the double knockout mice lacking calpain-1 and PTP1B showed only a partial rescue of the spreading phenotype. In non-adherent platelets, proteolysis and GTPase activity of RhoA and Rac1 were indistinguishable between the wild-type (WT) and calpain-1−/− platelets. In contrast, the ECM-adherent calpain-1−/− platelets showed higher Rac1 activity at the beginning of spreading, whereas RhoA was more active at later time points. The ECM-adherent calpain-1−/− platelets showed an elevated level of RhoA protein but not Rac1 and Cdc42. Proteolysis of recombinant RhoA, but not Rac1 and Cdc42, indicates that RhoA is a calpain-1 substrate in vitro. Potentiation of the platelet spreading phenotype in calpain-1−/− mice suggests a novel role of calpain-1 in hemostasis, and may explain the normal bleeding time observed in the calpain-1−/− mice.
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影响因子：
7.8
作者：
Bialkowska, K;Kulkarni, S;Fox, JEB
通讯作者：
Fox, JEB
影响因子：
10.4
作者：
Calaminus, S. D. J.;Thomas, S.;Watson, S. P.
通讯作者：
Watson, S. P.
影响因子：
--
作者：
BRACE, LD;VENTON, DL;LEBRETON, GC
通讯作者：
LEBRETON, GC
DOI：
10.1083/jcb.200703185
发表时间：
2007-11-05
期刊：
The Journal of cell biology
影响因子：
--
作者：
Flevaris P;Stojanovic A;Gong H;Chishti A;Welch E;Du X
通讯作者：
Du X
影响因子：
--
作者：
Dutt P;Croall DE;Arthur JS;Veyra TD;Williams K;Elce JS;Greer PA
通讯作者：
Greer PA