SNARE PRE-FUSION INTERMEDIATE WITH INHIBITORY PEPTIDES

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 SNARE介导的膜融合是包括突触囊泡融合在内的所有囊泡运输途径中保守的重要过程。神经元融合需要三个SNARE蛋白，位于质膜上的t-SNARE Synaxin和SNAP-25，以及与突触小泡结合的v-SNARE Vamp2。此外，许多调节蛋白确保了神经递质的高效和及时的排泄。复合素是一种广为人知的融合抑制调节因子，但其作用模式仍存在争议。我们正在研究一种含有Synaxin、SNAP-25和Vamp2的截断神经元陷阱。这种复合体类似于一个部分组装的融合前陷阱中间体，络合素被认为对其起作用。我们已经得到了这种络合物的单独晶体和与络合蛋白衍生的多肽的共晶。已知这些多肽与SNARE复合体结合并抑制融合。这些多肽的作用方式尚不完全清楚，但它们被认为在融合前状态下稳定了SNARE复合体。我们的结构研究将为从机制上理解络合素调节SNARE融合提供分子基础。最终，这将有助于解释突触小泡融合是如何进行的。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. SNARE-mediated membrane fusion is an essential process conserved in all vesicular trafficking pathways, including synaptic vesicle fusion in neurotransmission. Neuronal fusion requires three SNARE proteins, the t-SNAREs Syntaxin and SNAP-25 located at the plasma membrane, and the v-SNARE Vamp2 which is bound to the synaptic vesicle. In addition, a number of regulatory proteins ensure efficient and timely exocytosis of neurotransmitters. Complexin is a well-known inhibitory regulator of fusion, but its mode of action remains controversial.We are working with a truncated neuronal SNARE containing Syntaxin, SNAP-25, and Vamp2. This complex resembles a partially assembled SNARE pre-fusion intermediate on which complexin is thought to act. We have obtained crystals of this complex alone and co-crystals with peptides derived from complexin. These peptides are known to bind to the SNARE complex and inhibit fusion. The mode of action of these peptides is not fully understood, but they are thought to stabilize the SNARE complex in the pre-fusion state.Our structural studies will provide the molecular basis for a mechanistic understanding on how SNARE fusion is regulated by complexin. Ultimately, this will help explaining how synaptic vesicle fusion is orchestrated.