Examining the function of biological sex specific genes: the NLGN4s

摘要 NLGN在突触发生和突触后致密物的成熟中起着重要作用 通过募集和与支架蛋白、神经递质受体和离子相互作用， 渠道已经表明，NRXN结合对于NLGN功能是至关重要的，因为NRXN能够 在突触后密度（PSD）聚集NLGN并启动下游相互作用的募集， 突触稳定和成熟所必需的蛋白质。大多数脊椎动物拥有四个NLGN基因： NLGN 1、NLGN 2、NLGN 3和NLGN 4。在大多数哺乳动物中，NLGN 4位于X染色体上， 然而，在更高级的灵长类动物如智人和黑猩猩中，NLGN 4X是互补的， 在Y染色体上（有时称为NLGN 5），与NLGN 4X具有近98%的同源性。是 我认为这种NLGN 4Y亚型起源于最近发生的一个复制事件 与几乎所有的脊椎动物不同，人类拥有X染色体和Y染色体。 NLGN 4的亚型，然而NLGN 4在突触处的功能仍然未知。我们打算 研究NLGN4X和NLGN4Y的功能特性，如NRXN结合，突触发生， 和本地化。 我们计划通过以下三个具体目标来解决这些问题：1）确定 NLGN4X和NLGN4Y是否定位于人类突触位点。2)确定的亲和力 NLGN4X和NLGN4Y用于NRXN。3)确定负责的分子机制 NLGN4X和NLGN4Y的突触发生活性的差异。我们进行了实验， 这表明我们能够实现我们提出的三个雄心勃勃的目标中的每一个目标。为特定 目的1：建立研究人脑组织和细胞中NLGN功能的方法。为特定 目的2，我们已经建立了一种测定法，并开始实验，以确定NLGN 4在 生物性别特异性组合。对于具体目标3，我们已经开始使用突触进行实验， 分析系统，并表达NLGN 4 X和NLGN 4 Y，并产生构建体以开始结构功能 分析.这些初步数据表明，我们准备在我们的 了解这些两性异形基因。这些结果可能有助于阐明突触 在ASD和学习障碍等疾病中的功能障碍，并提出了 雄性和雌性之间的突触功能。

Abstract NLGNs are known to play crucial roles in synaptogenesis and the maturation of the postsynaptic density through recruitment of and interactions with scaffolding proteins, neurotransmitter receptors, and ion channels. It has been shown that NRXN binding is crucial for NLGN function, as NRXN is capable of clustering NLGNs at the postsynaptic density (PSD) and initiating recruitment of downstream interacting proteins necessary for synapse stabilization and maturation. Most vertebrates possess four NLGN genes: NLGN1, NLGN2, NLGN3, and NLGN4. In most mammals, NLGN4 is located on the X chromosome, however in higher order primates such as Homo sapiens and Pan troglodytes NLGN4X is complemented on the Y chromosome (sometimes referred to as NLGN5) with nearly 98% homology to NLGN4X. It is believed that this NLGN4Y isoform originated from a duplication event that occurred relatively recently during evolution Unlike almost all vertebrates, humans possess X chromosome and Y chromosome isoforms of NLGN4, however the function of NLGN4 at synapses remains unknown. We intend to investigate the functional properties of NLGN4X and NLGN4Y such as NRXN binding, synaptogenesis, and localization. We plan on addressing these questions with the following three specific aims: 1) Determine whether NLGN4X and NLGN4Y are localized to human synaptic sites. 2) Determine the affinities of NLGN4X and NLGN4Y for NRXN. 3) Determine the molecular mechanism responsible for differences in the synaptogenic activity of NLGN4X and NLGN4Y. We have conducted experiments to demonstrate that we can achieve the goals of each of the three ambitious aims we proposed. For specific aim 1, we established approaches to study NLGN function in human brain tissue and cells. For Specific aim 2, we have established an assay and begun experiments to determine the affinity of NLGN4 in biological sex-specific combinations. For specific aim 3, we have begun experiments using a synapse assay system and expressed NLGN4X and NLGN4Y and generated constructs to begin structure function analysis. Together these preliminary data indicate that we are poised to make rapid progress on our understanding of these sexually dimorphic genes. Results are likely to shed light on the matter of synaptic dysfunction in disorders such as ASD and learning disabilities and propose a potential difference in synaptic function between males and females.