Myristoylation-dependent binding of HIV-1 Nef to CD4.
Myristoylation-dependent binding of HIV-1 Nef to CD4.
复制标题
HIV-1 Nef 与 CD4 的肉豆蔻酰化依赖性结合。
DOI：
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发表时间：
1994
影响因子：
5.6
通讯作者：
J. Neil
中科院分区：
文献类型：
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作者：
M. Harris;J. Neil
nef基因在整个灵长类慢病毒家族中是保守的。尽管在体外是不稳定的，但SIV nef突变体未能建立持续的病毒血症表明nef在体内具有重要作用。尽管Nef蛋白的生化功能仍然不明确，但随着可重复的观察，出现了一个一致的主题，即Nef表达导致细胞表面标记物CD 4的下调。下调需要CD 4胞质结构域内的氨基酸序列，但通过不同于正常丝氨酸磷酸化依赖性途径的机制发生。由于CD 4是一种跨膜糖蛋白，Nef是一种靶向质膜细胞质表面的肉豆蔻酰化蛋白，我们认为Nef和CD 4之间的直接相互作用可能在下调中起作用。在这里，我们证明了杆状病毒表达的Nef-GST融合蛋白与CD 4特异性相互作用。这种相互作用需要在同一细胞中共表达，并且依赖于Nef豆蔻酰化。Nef相互作用的位点映射到CD 4的胞质结构域，因为缺乏该结构域的缺失突变体不能与Nef相互作用。这一观察结果为Nef的生化功能提供了新的线索，并为HIV化疗的未来发展提供了新的机会。
The nef gene is conserved throughout the primate lentivirus family. Although dispensable in vitro, an important role for nef in vivo is suggested by the failure of SIV nef mutants to establish persistent viraemia. Although the biochemical function of the Nef protein remains equivocal, a consistent theme has emerged with the reproducible observation that Nef expression results in the down-modulation of the cell surface marker CD4. Down-modulation requires amino acid sequences within the cytoplasmic domain of CD4 but occurs by a mechanism distinct from the normal serine phosphorylation-dependent pathway. As CD4 is a transmembrane glycoprotein and Nef a myristoylated protein targeted to the cytoplasmic face of the plasma membrane we considered that a direct interaction between Nef and CD4 might play a role in down-modulation. Here we demonstrate that a baculovirus-expressed Nef-GST fusion protein interacts specifically with CD4. This interaction requires co-expression in the same cell and is dependent on Nef myristoylation. The site of Nef interaction maps to the cytoplasmic domain of CD4, as a deletion mutant lacking this domain fails to interact with Nef. This observation sheds new light on the biochemical function of Nef and offers new opportunities for the future development of HIV chemotherapy.