The factor H protein family
The factor H protein family
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DOI：
10.1016/s0162-3109(99)00015-6
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发表时间：
1999-05-01
期刊：
影响因子：
--
通讯作者：
Meri, S
中科院分区：
文献类型：
--
作者：
Zipfel, PF;Jokiranta, TS;Meri, S
因子H基因家族提供了多结构域多功能蛋白质家族的一个最好的例子，其单个成员由保守的共同结构元件定义，并显示不同但经常重叠的功能。该蛋白质家族的六个鉴定成员代表主要在肝脏中合成的分泌型血浆蛋白。在这里，我们总结了目前的理解，这些蛋白质的功能，并建议在补体控制的共同作用。因子H是最具特征的成员，并作为补体调节剂。该蛋白质在中心补体成分C3 B的降解中显示因子I的辅因子活性，充当C3转化酶C3 bB B b的衰变加速因子，并且是与C3 B结合的因子B的竞争者。因子H是一种多功能蛋白质，在补体系统外发挥功能：它与细胞整联蛋白受体（CD 11b/CD 18）结合，与细胞表面糖胺聚糖相互作用，还与某些病原微生物的表面结合。此外，因子H有几个C3蛋白的结合位点。因子H样蛋白1（FHL-1）或Recectin与因子H共享补体调节功能，并与肝素相互作用。该蛋白质显示细胞铺展活性并结合链球菌M蛋白的N-末端。H因子相关蛋白（FHR-1至FHR-4）的功能目前正在研究中。这些蛋白质分布不同。三种蛋白质（FHR-1、FHR-2和FHR-4）是脂蛋白的组分，而FHR-3与肝素相互作用。已证明FHR-3和FHR-4与C3 b和C3 d结合，并且这两种蛋白质显示出辅因子相关活性。(C)1999 Elsevier Science B. V.保留所有权利。
The factor H gene family provides a prime example of a multidomain multifunctional protein family whose individual members are defined by conserved common structural elements and display diverse but often overlapping functions. The six identified members of this protein family represent secreted plasma proteins that are primarily synthesized in the liver. Here, we summarize the current understanding of the function of these proteins and suggest a common role in complement control. Factor H is the best characterized member and acts as a complement regulator. The protein displays cofactor activity for factor I in the degradation of the central complement component C3b, acts as a decay accelerating factor for the C3 convertase, C3bBb and is a competitor for factor B binding to C3b. Factor H is a multifunctional protein and displays functions outside the complement system: it binds to the cellular integrin receptor (CD11b/CD18), interacts with cell surface glycosaminoglycans and also binds to the surface of certain pathogenic microorganisms. In addition, factor H has several binding sites for the C3 protein. The factor H-like protein 1 (FHL-1) or reconectin shares the complement regulatory functions with factor H and interacts with heparin. The protein displays cell spreading activity and binds to the N-terminus of the streptococcal M protein. The function of the factor H-related proteins (FHR-1 to FHR-4) is currently under investigation. These proteins are differently distributed. Three proteins (FHR-1, FHR-2 and FHR-4) are constituents of lipoproteins, while FHR-3 interacts with heparin. Binding to C3b and C3d has been demonstrated for FHR-3 and FHR-4 and the two proteins display a cofactor related activity. (C) 1999 Elsevier Science B.V. All rights reserved.