The importance of N-glycosylation on β(3) integrin ligand binding and conformational regulation.
The importance of N-glycosylation on β(3) integrin ligand binding and conformational regulation.
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DOI：
10.1038/s41598-017-04844-w
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发表时间：
2017-07-05
影响因子：
4.6
通讯作者：
Zhu J
中科院分区：
文献类型：
--
作者：
Cai X;Thinn AMM;Wang Z;Shan H;Zhu J
N-糖基化可以调节整合素的粘附功能。在18 α和8 β整合素亚基中发现了N-糖基化位点的数量和分布的巨大差异。αIIbβ3和αVβ3的晶体结构已经解析了每个N-聚糖位点的精确结构位置，但单个N-聚糖位点对整合素活化的结构影响仍不清楚。通过定点突变和结构导向分析，我们剖析了单个N-聚糖位点在β3整合素活化中的功能。我们发现，N-聚糖位点，头片段和腿结构域界面处的β3-N320正调节αIIbβ3，但不调节αVβ3活化。β3-I-EGF 3和α IIb-calf-1结构域界面处的β3-N559 N-聚糖以及β3-β-尾和α IIb-calf-2结构域界面处的β3-N654 N-聚糖正调控αIIbβ3和αVβ3整联蛋白的活化。相反，去除β3杂合物和I-EGF 3界面附近的β3-N371 N-聚糖或I-EGF 1结构域处的β3-N452 N-聚糖使得β3整联蛋白比野生型更有活性。我们在β1亚基的βI结构域鉴定了一个独特的N-聚糖，其负调节α5β1活化。我们的研究表明，庞大的N-聚糖影响大规模的构象重排，潜在的稳定或不稳定的结构域界面的整合素。
N-glycosylations can regulate the adhesive function of integrins. Great variations in both the number and distribution of N-glycosylation sites are found in the 18 α and 8 β integrin subunits. Crystal structures of αIIbβ3 and αVβ3 have resolved the precise structural location of each N-glycan site, but the structural consequences of individual N-glycan site on integrin activation remain unclear. By site-directed mutagenesis and structure-guided analyses, we dissected the function of individual N-glycan sites in β3 integrin activation. We found that the N-glycan site, β3-N320 at the headpiece and leg domain interface positively regulates αIIbβ3 but not αVβ3 activation. The β3-N559 N-glycan at the β3-I-EGF3 and αIIb-calf-1 domain interface, and the β3-N654 N-glycan at the β3-β-tail and αIIb-calf-2 domain interface positively regulate the activation of both αIIbβ3 and αVβ3 integrins. In contrast, removal of the β3-N371 N-glycan near the β3 hybrid and I-EGF3 interface, or the β3-N452 N-glycan at the I-EGF1 domain rendered β3 integrin more active than the wild type. We identified one unique N-glycan at the βI domain of β1 subunit that negatively regulates α5β1 activation. Our study suggests that the bulky N-glycans influence the large-scale conformational rearrangement by potentially stabilizing or destabilizing the domain interfaces of integrin.