Celllular mechanisms of neuronal metal transport and toxicity

描述(申请人提供)：神经元锌参与兴奋性神经传递的调节等关键过程。相比之下，神经元特别容易受到这种金属过量的影响。为了平衡这些相反的影响，细胞具有精细控制细胞质中游离金属浓度的机制。在这些机制中，细胞器金属固存的锌稳态依赖于ZNT/SLC30锌转运蛋白家族成员。这些机制是本应用程序的重点。神经元内主要的ZNT/SLC30锌转运蛋白是锌转运蛋白。ZnT3位于突触小泡中，它的遗传缺陷调节了从癫痫到阿尔茨海默病的各种病理过程。在我们之前的资助期间，我们发现了zt3的分布和锌的转运活性受其齐聚作用的控制。 州政府。三价锌二聚体通过氧化还原机制催化生成的锌酪氨酸键赋予细胞对锌毒性的抗性。这是第一个膜蛋白受二硫代酪氨酸键调节的例子。我们认为，通过氧化还原机制，隔室特异性的转运蛋白齐聚调节了金属的毒性抗性。在这一应用中，我们在体外和体内使用二聚化功能获得和功能丧失突变I ZnT3以及在运输和运输途径中携带缺陷或功能获得的小鼠来验证这一假说。我们的研究将影响我们对急性和慢性神经系统疾病过程的理解和可能的治疗，在这些过程中，锌发挥着作用，如癫痫和阿尔茨海默病。

DESCRIPTION (provided by applicant): Neuronal zinc participates in key processes such as modulation of excitatory neurotransmission. In contrast, neurons are particularly susceptible to excess of this metal. To balance these opposing effects, cells possess mechanisms to finely control free cytoplasmic metal concentration. Among these mechanisms, zinc homeostasis by organelle metal sequestration relies on ZnT/SLC30 zinc transporter family members. These mechanisms are the focus of this application. The main ZnT/SLC30 zinc transporter in neurons is ZnT3. ZnT3 is located in synaptic vesicles and its genetic deficiency modulates pathology ranging from epilepsy to Alzheimer's disease. During our previous funding period, we discovered that ZnT3 distribution and zinc transport activity are controlled by its oligomerization state. ZnT3 dimers confer cellular resistance to zinc toxicity by an inter-ZnT3 dityrosine bond whose generation is catalyzed by redox mechanisms. This is the first example of a membrane protein regulated by dityrosine bonds. We propose that compartment-specific ZnT3 transporter oligomerization by redox mechanisms regulates metal toxicity resistance. In this application, we test this hypothesis in vitro and in vivo using dimerization gain- and loss-of-function mutations i ZnT3 as well as mice carrying deficiencies or gain-of-function in the ZnT3 trafficking and transport pathways. Our studies will impact our understanding and possibly treatment of acute and chronic neurological disease processes where zinc play a role such as epilepsy and Alzheimer's disease.