The chicken yolk sac IgY receptor, a functional equivalent of the mammalian MHC-related Fc receptor, is a phospholipase A2 receptor homolog
The chicken yolk sac IgY receptor, a functional equivalent of the mammalian MHC-related Fc receptor, is a phospholipase A2 receptor homolog
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DOI：
10.1016/s1074-7613(04)00113-x
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发表时间：
2004-05-01
期刊：
影响因子：
32.4
通讯作者：
Bjorkman, PJ
中科院分区：
文献类型：
--
作者：
West, AP;Herr, AB;Bjorkman, PJ
在哺乳动物中，IgG通过mhc相关受体FcRn从母体传递给幼崽，FcRn将IgG结合在酸性内体中，并以碱性pH释放到血液中。母体IgY，鸟类IgG的对应物，通过卵黄囊膜转移到胚胎中。对鸡卵黄囊IgY受体（FcRY）进行亲和纯化，并对其基因进行测序。FcRY与MHC分子无关，但它是哺乳动物磷脂酶a(2)受体的同源物。分析性超离心和截断实验表明，FcRY在酸性pH下形成含有IgY结合位点的致密结构，但在碱性pH下发生构象变化，破坏了该位点。因此，在ph依赖性结合的结构和机制上，FcRn与哺乳动物的FcRn无关，说明了进化中用于转移抗体的不同途径。
In mammals, IgG is transferred from mother to young by the MHC-related receptor FcRn, which binds IgG in acidic endosomes and releases it at basic pH into blood. Maternal IgY, the avian counterpart of IgG, is transferred to embryos across yolk sac membranes. We affinity-purified the chicken yolk sac IgY receptor (FcRY) and sequenced its gene. FcRY is unrelated to MHC molecules but is a homolog of the mammalian phospholipase A(2) receptor. Analytical ultracentrifugation and truncation experiments suggest that FcRY forms a compact structure containing an IgY binding site at acidic pH but undergoes a conformational change at basic pH that disrupts the site. FcRY is thus unrelated to mammalian FcRn in both its structure and mechanism for pH-dependent binding, illustrating distinct routes utilized by evolution to transfer antibodies.