人类编码补体调节剂 C4结合蛋白(C4bp)、补体第一受体(C3b/C4b受体、CR1)及 H 因子(H)的基因紧密连锁,称为补体激活调节剂(RCA)基因簇。最近,用 CR1 cDNA 探针原位杂交实验将RCA 基因簇定位于人类第1号染色体长臂上。C2,B 因子,C4bp、H 及 CR1又均为新近称作与 C3b/C4b结合的蛋白家族的成员,并存在共同的由约60个氨基酸残基组成的重复单位及高度保守残基组成的结构,这提示这些蛋白质在进化上源于一个共同的祖先。衰变加速因子(DAF)为一膜糖蛋白,与 C4bp、CR1及 H 相似,能结合 C3b 或 C4b,从而抑制 C3转化酶的形成,但并不作为Ⅰ因子裂解 C3b 及 C4b 的辅因子.阵发性睡眠性血红蛋白尿(PNH)患者红细胞 The gene encoding human complement regulatory C4 binding protein (C4bp), complement first receptor (C3b / C4b receptor, CR1) and H factor (H) are closely linked and are called complement activation regulator (RCA) gene cluster. Recently, the RCA gene cluster was located on the long arm of human chromosome 1 using in situ hybridization with the CR1 cDNA probe. The C2, B factors, C4bp, H and CR1 are each a member of a family of proteins newly termed C3b / C4b-binding protein and present a common structure consisting of a repeat unit of about 60 amino acid residues and a highly conserved residue , Suggesting that these proteins evolved from a common ancestor. The decay accelerating factor (DAF) is a membrane glycoprotein that, like C4bp, CR1 and H, binds to C3b or C4b and thus inhibits the formation of C3 convertase but does not act as a cofactor for the cleavage of C3b and C4b by factor I. Sexually active hemoglobinuria (PNH) patients with red blood cells