Characterization of the heparin/heparan sulfate binding site of the natural cytotoxicity receptor NKp46.
Characterization of the heparin/heparan sulfate binding site of the natural cytotoxicity receptor NKp46.
复制标题
天然细胞毒性受体 NKp46 的肝素/硫酸乙酰肝素结合位点的表征。
作者：
Alon Zilka;Guy Landau;O. Hershkovitz;Noga Bloushtain;A. Bar;F. Benchetrit;E. Fima;T. V. van Kuppevelt;J. Gallagher;S. Elgavish;A. Porgador
NKp46 是一组统称为天然细胞毒性受体 (NCR) 的受体的成员，由自然杀伤 (NK) 细胞表达。 NCR 能够介导 NK 细胞直接杀死肿瘤和病毒感染的细胞。我们最近发现 NKp46 识别膜硫酸乙酰肝素蛋白聚糖 (HSPG) 的硫酸乙酰肝素部分，从而使 NK 细胞能够裂解肿瘤细胞。在当前的研究中，我们进一步检查了 NKp46 中可能参与硫酸乙酰肝素与肿瘤细胞结合的残基。根据静电势图以及与人纤连蛋白上肝素结合位点的比较，我们预测包含碱性氨基酸 K133、R136、H139、R142 和 K146 的连续区域参与 NKp46 与硫酸乙酰肝素的结合。将 NKp46D2 上的这些氨基酸突变为不带电荷的氨基酸保留了其病毒结合能力，但在与肝素的直接结合测试中降低了其与肿瘤细胞的结合，K(D) 降低了 10-100 倍。 NKp46 识别的肝素/硫酸乙酰肝素表位的最小长度是八个糖，根据结构预测并通过测试肝素寡聚物证明。测试选择性单脱硫肝素寡聚物强调了 O-硫酸化、N-硫酸化和 N-乙酰化对 NKp46 表位识别的具体贡献。 NKp46 中硫酸乙酰肝素结合区域的表征可以进一步深入了解 NKp46 配体的身份以及 NK 与癌症的相互作用。
NKp46 is a member of a group of receptors collectively termed natural cytotoxicity receptors (NCRs) that are expressed by natural killer (NK) cells. NCRs are capable of mediating direct killing of tumor and virus-infected cells by NK cells. We have recently shown that NKp46 recognizes the heparan sulfate moieties of membranal heparan sulfate proteoglycans (HSPGs), thus enabling lysis of tumor cells by NK cells. In the current study, we further examined the residues in NKp46 that may be involved in heparan sulfate binding on tumor cells. On the basis of both the electrostatic potential map and comparison to the heparin binding site on human fibronectin, we predicted a continuous region containing the basic amino acids K133, R136, H139, R142, and K146 to be involved in NKp46 binding to heparan sulfate. Mutating these amino acids on NKp46D2 to noncharged amino acids retained its virus binding capacity but reduced its binding to tumor cells with a 10-100 fold lower K(D) when tested for direct binding to heparin. The minimal length of the heparin/heparan sulfate epitope recognized by NKp46 was eight saccharides as predicted from the structure and proven by testing heparin oligomers. Testing selectively monodesulfated heparin oligomers emphasized the specific contributions of O-sulfation, N-sulfation, and N-acetylation to epitope recognition by NKp46. The characterization of heparan sulfate binding region in NKp46 offers further insight into the identity of the ligands for NKp46 and the interaction of NK and cancers.
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影响因子：
15.9
作者：
Kleeff, J;Ishiwata, T;Korc, M
通讯作者：
Korc, M
具有黑色素瘤粘附和肝素结合活性的纤连蛋白肽的定位和化学合成。
影响因子：
2.9
作者：
McCarthy,JB;Chelberg,MK;Mickelson,DJ;Furcht,LT
通讯作者：
Furcht,LT
纤连蛋白合成肽 FN-C/H II 的结构特征，负责细胞粘附、神经突延伸和硫酸乙酰肝素结合。
DOI：
--
发表时间：
1993
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Drake,SL;Varnum,J;Mayo,KH;Letourneau,PC;Furcht,LT;McCarthy,JB
通讯作者：
McCarthy,JB
影响因子：
2.9
作者：
Ibrahimi, OA;Zhang, FM;Linhardt, RJ
通讯作者：
Linhardt, RJ
影响因子：
3.9
作者：
Fromm, JR;Hileman, RE;Linhardt, RJ
通讯作者：
Linhardt, RJ