Treiger B F, Leonard W J, Svetlik P, Rubin L A, Nelson D L, Greene W C
J Immunol. 1986 Jun 1;136(11):4099-105.
The DNA sequence encoding all of the putative intracytoplasmic domain and most of the trans-membrane domain of the human IL 2 receptor was deleted from a full length receptor cDNA. After expression in mouse L cells, the resultant "anchor minus" cDNA was found to direct the synthesis of a secreted rather than membrane-associated form of the IL 2 receptor. The secreted receptor protein (44,000 to 46,000 Mr) retained the capacity to bind both IL 2 and the monoclonal anti-Tac antibody, as evidenced by retention on IL 2 and anti-Tac affinity columns, inhibition of [3H]-anti-Tac binding to HUT 102B2 cells, and partial inhibition of IL 2-induced CTLL proliferation. Removal of these domains from the IL 2 receptor did not alter the posttranslational processing or rate of export of the truncated receptor protein. These data confirm the proposed membrane orientation of the IL 2 receptor (NH2 terminus out, COOH terminus in) and underscore the anchoring function of this carboxy terminal receptor segment. The availability of such anchor minus receptor cDNA constructs may facilitate purification of large quantities of receptor protein for further analysis of receptor structure, valency, and localization of the IL 2 binding site(s).
从人白细胞介素2（IL-2）受体的全长cDNA中删除了编码所有推定的胞质内结构域和大部分跨膜结构域的DNA序列。在小鼠L细胞中表达后，发现所得的“无锚定”cDNA指导合成一种分泌型而非膜相关型的IL-2受体。分泌的受体蛋白（分子量为44,000至46,000）保留了结合IL-2和抗Tac单克隆抗体的能力，这通过其在IL-2和抗Tac亲和柱上的保留、抑制[3H] -抗Tac与HUT 102B2细胞的结合以及部分抑制IL-2诱导的CTLL增殖得以证明。从IL-2受体中去除这些结构域不会改变截短的受体蛋白的翻译后加工或输出速率。这些数据证实了所提出的IL-2受体的膜取向（氨基末端向外，羧基末端向内），并强调了该羧基末端受体片段的锚定功能。这种无锚定受体cDNA构建体的可用性可能有助于纯化大量的受体蛋白，以进一步分析受体结构、价态和IL-２结合位点的定位。
