Deciphering the human platelet sheddome
Deciphering the human platelet sheddome
复制标题
DOI：
10.1182/blood-2010-05-283838
复制
发表时间：
2011-01-06
期刊：
影响因子：
20.3
通讯作者：
Brass, Lawrence F.
中科院分区：
文献类型：
--
作者：
Fong, Karen P.;Barry, Colin;Brass, Lawrence F.
活化的血小板脱落表面蛋白，可能改变血小板功能并提供生物活性片段的来源。先前的研究已经确定了血小板脱落的几种成分，但脱落的全部程度尚不清楚。在这里，我们采取了一种全局方法，使用质谱分析活化血小板上清液中的蛋白质片段，并寻找源自血小板膜的蛋白质。去除血浆蛋白和微粒后，鉴定出 1048 种蛋白质，其中包括 69 种膜蛋白。几乎所有的膜蛋白之前都已被检测到，但只有 10 种膜蛋白被证明在血小板中脱落。其余59名候选人有待确认。根据光谱计数，棚顶中的蛋白质代表性差异很大。作为原理证明，我们验证了一种不太常检测到的蛋白质，即信号蛋白 7A，该蛋白以前从未在血小板中被发现。信号蛋白 7A 的表面表达、裂解和脱落以及它与 α 颗粒的关联都得到了证明。最后，ADAM17（一种已知的脱落酶）抑制剂大大减少了信号蛋白 7A 和其他 12 种蛋白质的裂解。这些结果将膜蛋白的一个子集定义为脱落细胞候选者，为进一步研究胞外域脱落对血小板功能的影响奠定了基础。 （血。2011；117(1):e15-e26）
Activated platelets shed surface proteins, potentially modifying platelet function as well as providing a source of bioactive fragments. Previous studies have identified several constituents of the platelet sheddome, but the full extent of shedding is unknown. Here we have taken a global approach, analyzing protein fragments in the supernate of activated platelets using mass spectroscopy and looking for proteins originating from platelet membranes. After removing plasma proteins and microparticles, 1048 proteins were identified, including 69 membrane proteins. Nearly all of the membrane proteins had been detected previously, but only 10 had been shown to be shed in platelets. The remaining 59 are candidates subject to confirmation. Based on spectral counts, protein representation in the sheddome varies considerably. As proof of principle, we validated one of the less frequently detected proteins, semaphorin 7A, which had not previously been identified in platelets. Surface expression, cleavage, and shedding of semaphorin 7A were demonstrated, as was its association with alpha-granules. Finally, cleavage of semaphorin 7A and 12 other proteins was substantially reduced by an inhibitor of ADAM17, a known sheddase. These results define a subset of membrane proteins as sheddome candidates, forming the basis for further studies examining the impact of ectodomain shedding on platelet function. (Blood. 2011;117(1):e15-e26)