Establishment and Analysis of mice disrupted with DNAM-1 gene

DNAM-1是由CTL和NK细胞介导的细胞功能的信号转换聚合物分子。交叉链接的DNAM-1与反DNAM-1 mAb诱导的细胞基化由CTL和NK细胞介导，也有DNA-1分子酪氨酸磷酸化的结果。我们研究了DNAM-1介导的信号和聚合的规则。我们在这里报告PKC活性的特定抑制剂，这些抑制剂预防了NK细胞的DNA-1介导细胞活性。DNAM-1的粘附与不需要的配体不同，如镁或钙，由PKC调节，由PMA增强的DNAM-1粘附和由特定PKC抑制剂抑制的抑制进行说明。Mutation of the putative PKC binding site in the cytoplasmic domain of DNAM-1（SeryD1329 yD1 to PheyD1329 yD1） prevents ligand binding and PMA-induced serine phosphorylation of the DNAM-1 receptor。这些结果表明，PKC磷酸化Sery-D1329的DNA-1 D1对两种DNA-1偶氮和信号都具有关键作用，在DNA-1偶氮分子触发器细胞毒性介导的情况下，当DNA-1偶氮分子触发器由正常NK和T细胞诱导时，这一函数在光细胞偶氮缺陷综合症中被削弱NK细胞克隆。However，LFA-1细胞表面表达的遗传重构恢复了DNAM-1初始化反DNAM-1 mAb诱导的细胞毒性，并表明DNAM-1和LFA-1之间的功能关系。进一步研究表明LFA-1与NK细胞中的DNA-1物理相关，以及抗CD 3 mAb刺激的T细胞，对于DNA-1的丝氨酸磷酸化发挥了关键作用。在LFA-1诱导体中的酪氨酸磷酸化与DNAM-1结合，对于那些鳍蛋白酪氨酸激酶是负责任的。这些结果表明，DNAM-1被纳入LFA-1介导的内部信号。

DNAM-1 is a signal transducing adhesion molecule involved in the cytolytic function mediated by CTL and NK cells. Cross-linking DNAM-1 with anti-DNAM-1 mAb induces cytolysis mediated by CTL and NK cells and also results in tyrosine phosphorylation of the DNAM-1 molecule. We studied regulation of DNAM-1-mediated signaling and adhesion. We report here that specific inhibitors of PKC activity prevented DNAM-1-mediated cytolytic activation of NK cells. Adhesion of DNAM-1 to its ligand does not require divalent cations, such as magnesium or calcium, and is regulated by PKC, as demonstrated by augmentation of DNAM-1 adhesion by PMA and inhibition by specific PKC inhibitors. Mutation of the putative PKC binding site in the cytoplasmic domain of DNAM-1 (SerィイD1329ィエD1 to PheィイD1329ィエD1) prevents ligand binding and PMA-induced serine phosphorylation of the DNAM-1 receptor. These results indicate that PKC phosphorylates SerィイD1329ィエD1 of DNAM-1 and plays a critical role for both DNAM-1 adhesion and signaling.Whereas ligation of DNAM-1 adhesion molecule triggers cytotoxicity mediated by normal NK and T cells, this function was defective in NK cell clones from leukocyte adhesion deficiency syndrome. However, genetic reconstitution of cell surface expression of LFA-1 restored the ability of DNAM-1 to initiate anti-DNAM-1 mAb induced cytotoxicity, indicating a functional relationship between DNAM-1 and LFA-1. Further studies demonstrated that LFA-1 physically associates with DNAM-1 in NK cells and anti-CD3 mAb stimulated T cells, for which serine phosphorylation of DNAM-1 plays a critical role. In addition, cross-linking of LFA-1 induces tyrosine phosphorylation of DNAM-1, for which the fyn protein tyrosine kinase is responsible. These results indicate that DNAM-1 is involved in the LFA-1-mediated intracellular signals.