锌离子的排泄机制

Zinc is an important life-sustaining element, and a part of many proteins such as zinc finger proteins and superoxide dismuatse (Sod1). Zinc deficiency is a wide-spread disease, leading to developmental retardation, dermatitis, alopecia and suppressed immune response. However, zinc excess is also detrimental. Little is known about the molecular mechanism governing zinc homeostasis in multicellular organisms. In the past several years we systematically studied the absorptive mechanism of zinc in the Drosophila gut, but the excretion mechanism remains to be explored. Absorption and excretion are two indispensable aspects of homeostasis control. This proposal plans to use the model organism Drosophila to study the molecular mechanism of zinc excretion in order to have a basic understanding of this process. The results are expetected to fill the existing knowledge gap and provide a reference point for zinc excretion study in other animals in particular mammals including humans.

锌离子是生命活动的重要元素, 是很多蛋白质如锌指蛋白(zinc-finger protein)、超氧化物歧化酶(Sod1)的组成部分。 锌缺乏是人类普遍疾病, 导致发育障碍、皮肤溃烂、脱发以及免疫低下等症状, 但锌过多也有害。 关于多细胞生物锌代谢以及维持锌稳态的调节机制人们知道的不多,我们过去几年利用果蝇这一模式生物系统研究了锌离子的肠道吸收机制, 但是锌离子排泄机理人们知之甚少。 吸收和排泄是维持稳态的两个方面, 本研究计划利用果蝇系统研究锌离子的排泄机制, 期望对整个过程有个基本认识，填补这一研究方向的空白, 并为其他生物特别是哺乳动物包括人类的锌代谢研究提供参考。

锌离子在过量的情况下需要有解毒机制，机体是如何将过量的锌排出体外的？ 利用果蝇我们研究了马氏管在锌排泄解毒中的作用，发现ZIP71B（CG10006)和ZnT35C（CG31860)协同介导了锌离子的排泄，这两种蛋白表达都受锌离子浓度调节。 这种锌离子代谢和某种嘌呤代谢引起的肾结石有关。这是第一次较系统地研究了锌的排泄机制，该研究结果对哺乳类动物相关研究将有指导作用。