ALIX Is a Lys63-Specific Polyubiquitin Binding Protein that Functions in Retrovirus Budding
ALIX Is a Lys63-Specific Polyubiquitin Binding Protein that Functions in Retrovirus Budding
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DOI：
10.1016/j.devcel.2012.10.023
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发表时间：
2012-12-11
影响因子：
11.8
通讯作者：
Kopito, Ron R.
中科院分区：
文献类型：
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作者：
Dowlatshahi, Dara P.;Sandrin, Virginie;Kopito, Ron R.
泛素依赖信号的多样性归因于这种小蛋白形成不同类型共价连接的聚脲链的能力，以及解释这种分子语法的Ub结合蛋白的存在。我们使用亲和捕获/质谱法鉴定了ALIX， ESCRT通路的一个组成部分，作为Ub结合蛋白。我们报道了ALIX的V结构域直接和选择性地结合到k63连接的polyb链上，对由三个以上Ub组成的链表现出强烈的偏好。序列分析在V结构域的螺旋区单个a-螺旋表面上发现了两个潜在的Ub结合位点。这些假设的Ub结合位点的突变抑制了polyb与体外分离的V结构域的结合，并损害了慢病毒的出芽。这些数据揭示了K63 polyb与ALIX结合在逆转录病毒释放中的重要作用。
The diversity of ubiquitin (Ub)-dependent signaling is attributed to the ability of this small protein to form different types of covalently linked polyUb chains and to the existence of Ub binding proteins that interpret this molecular syntax. We used affinity capture/mass spectrometry to identify ALIX, a component of the ESCRT pathway, as a Ub binding protein. We report that the V domain of ALIX binds directly and selectively to K63-linked polyUb chains, exhibiting a strong preference for chains composed of more than three Ub. Sequence analysis identified two potential Ub binding sites on a single a-helical surface within the coiled-coil region of the V domain. Mutation of these putative Ub binding sites inhibited polyUb binding to the isolated V domain in vitro and impaired budding of lentiviruses. These data reveal an important role for K63 polyUb binding by ALIX in retroviral release.