Synaptotagmins I and II act as nerve cell receptors for botulinum neurotoxin G
Synaptotagmins I and II act as nerve cell receptors for botulinum neurotoxin G
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DOI：
10.1074/jbc.m403945200
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发表时间：
2004-07-16
影响因子：
4.8
通讯作者：
Binz, T
中科院分区：
文献类型：
--
作者：
Rummel, A;Karnath, T;Binz, T
肉毒杆菌神经毒素(BoNTs)通过选择性地进入胆碱能运动神经元和随后对囊泡融合机制的核心组件的特定切割而导致肌肉瘫痪。复杂的神经节苷脂是有效与神经细胞结合所必需的，但蛋白质受体是内化的关键。最近的工作证明，突触凝集素I和II可以作为BONT/B的蛋白质受体(董，M.，Richards，D.A.，Goodnough，M.C.，Tepp，W.H.，Johnson，E.A.和Chapman，E.R.(003)J.Cell Biol)。162、1293-1303)。在这里，我们报告了第二种BONT血清型的蛋白质受体。与BONT/B一样，BONT/G利用突触素I和II进入膈神经细胞。通过下拉实验，我们发现只有BoNT/G，而剩下的五个BoNTs和破伤风神经毒素都不能与突触素I和II相互作用。与BoNT/B相反，与这两种异构体的相互作用不依赖于神经节苷脂的存在。来源于突触素I和II腔结构域的多肽能够阻断ONT/G在膈神经制剂中的神经毒性。下拉和中和实验进一步确定了突触素I和II的膜并列的10个鲁米那氨基酸是神经毒素结合的关键片段。此外，我们还证明了BONT/B和BONT/G的细胞结合片段的羧基末端结构域介导了与其蛋白受体的相互作用。
Botulinum neurotoxins (BoNTs) induce muscle paralysis by selectively entering cholinergic motoneurons and subsequent specific cleavage of core components of the vesicular fusion machinery. Complex gangliosides are requisite for efficient binding to neuronal cells, but protein receptors are critical for internalization. Recent work evidenced that synaptotagmins I and II can function as protein receptors for BoNT/B (Dong, M., Richards, D. A., Goodnough, M. C., Tepp, W. H., Johnson, E. A., and Chapman, E. R. ( 003) J. Cell Biol. 162, 1293-1303). Here, we report the protein receptor for a second BoNT serotype. Like BoNT/B, BoNT/G employs synaptotagmins I and II to enter phrenic nerve cells. Using pull-down assays we show that only BoNT/G, but neither the five remaining BoNTs nor tetanus neurotoxin, interacts with synaptotagmins I and II. In contrast to BoNT/B, interactions with both isoforms are independent of the presence of gangliosides. Peptides derived from the luminal domain of synaptotagmin I and II are capable of blocking the neurotoxicity of BoNT/G in phrenic nerve preparations. Pull-down and neutralization assays further established the membrane-juxtaposed 10 luminal amino acids of synaptotagmins I and II as the critical segment for neurotoxin binding. In addition, we show that the carboxyl-terminal domain of the cell binding fragment of BoNT/B and BoNT/G mediates the interaction with their protein receptor.