SNARE PRE-FUSION INTERMEDIATE WITH INHIBITORY PEPTIDES

这个子项目是许多利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 SNARE介导的膜融合是所有囊泡运输途径中保守的重要过程，包括神经传递中的突触囊泡融合。神经元融合需要三种SNARE蛋白，位于质膜上的t-SNARE突触融合蛋白和SNAP-25，以及与突触囊泡结合的v-SNARE Vamp 2。此外，许多调节蛋白确保神经递质的有效和及时的胞吐作用。复合蛋白是一种众所周知的融合抑制调节因子，但其作用方式仍存在争议。我们正在研究一种截短的神经元SNARE，其中含有Syntaxin，SNAP-25和Vamp 2。该复合物类似于部分组装的SNARE融合前中间体，据信复合蛋白对其起作用。我们已经获得了这种复合物单独的晶体和与来自复合蛋白的肽的共晶体。已知这些肽与SNARE复合物结合并抑制融合。这些肽的作用模式还不完全清楚，但他们被认为是稳定的SNARE复合物在pre-fusion状态。我们的结构研究将提供一个机制的理解SNARE融合是如何调控complexin的分子基础。最终，这将有助于解释突触囊泡融合是如何协调的。

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.