Syntenin-1 is a new component of tetraspanin-enriched microdomains: Mechanisms and consequences of the interaction of syntenin-1 with CD63
Syntenin-1 is a new component of tetraspanin-enriched microdomains: Mechanisms and consequences of the interaction of syntenin-1 with CD63
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DOI：
10.1128/mcb.00849-06
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发表时间：
2006-10-01
影响因子：
5.3
通讯作者：
Berditchevski, Fedor
中科院分区：
文献类型：
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作者：
Latysheva, Nadya;Muratov, Gairat;Berditchevski, Fedor
四跨膜蛋白聚集在质膜上的特定微区（称为四跨膜蛋白富集微区，或TERM）中，并调节相关跨膜受体（包括整合素和受体酪氨酸激酶）的功能。我们已经确定了syntenin-1，一个PDZ结构域的蛋白质，作为一个新的组成部分的TERM，并显示syntenin-1特异性相互作用的四跨膜蛋白CD 63。详细的生物化学和异源磁共振光谱（NMR）研究表明，相互作用是介导的C-末端细胞质区域的四跨膜蛋白和PDZ结构域的syntenin-1。在相互作用后，NMR化学位移扰动主要定位于PDZ 1结合口袋周围的残基，表明CD 63细胞质尾区的特定识别模式。此外，syntenin-1的C末端在CD 63-syntenin-1缔合中具有稳定作用，因为最后17个氨基酸的缺失消除了相互作用。CD 63-syntenin-1复合物在质膜上是丰富的，并且野生型syntenin-1的表达升高减缓了四跨膜蛋白的组成性内化。此外，在表达缺少前100个氨基酸的syntenin-1突变体的细胞中，CD 63的内化被完全阻断。先前的结果表明，CD 63通过AP-2依赖性机制内化。因此，我们的数据表明，syntenin-1可以抵消AP-2依赖的内化，并确定这种串联PDZ蛋白作为一种新的内吞调节剂。
Tetraspanins are clustered in specific microdomains (named tetraspanin-enriched microdomains, or TERM) in the plasma membrane and regulate the functions of associated transmembrane receptors, including integrins and receptor tyrosine kinases. We have identified syntenin-1, a PDZ domain-containing protein, as a new component of TERM and show that syntenin-1 specifically interacts with the tetraspanin CD63. Detailed biochemical and heteronuclear magnetic resonance spectroscopy (NMR) studies have demonstrated that the interaction is mediated by the C-terminal cytoplasmic region of the tetraspanin and the PDZ domains of syntenin-1. Upon interaction, NMR chemical shift perturbations were predominantly localized to residues around the binding pocket of PDZ1, indicating a specific mode of recognition of the cytoplasmic tail of CD63. In addition, the C terminus of syntenin-1 has a stabilizing role in the CD63-syntenin-1 association, as deletion of the last 17 amino acids abolished the interaction. The CD63-syntenin-1 complex is abundant on the plasma membrane, and the elevated expression of the wild-type syntenin-1 slows down constitutive internalization of the tetraspanin. Furthermore, internalization of CD63 was completely blocked in cells expressing a syntenin-1 mutant lacking the first 100 amino acids. Previous results have shown that CD63 is internalized via AP-2-dependent mechanisms. Hence, our data indicate that syntenin-1 can counteract the AP-2-dependent internalization and identify this tandem PDZ protein as a new regulator of endocytosis.