CLONING OF MAMMALIAN LIVER IRON TRANSPORTER, DMT2

我一直被金属离子作为许多不同生物过程的重要辅助因子的巨大重要性所吸引，包括基因调控、自由基稳态和无数其他催化反应。我最近克隆的DMT1（以前称为DCT1）是一种接受多种过渡金属离子的跨膜转运蛋白。自然发生的DMT1突变提供了令人信服的证据，表明它在肠道和骨髓铁摄取中起主要作用。然而，正如我在研究计划部分所描述的那样，我们假设必须存在至少一种不同于DMT1的额外跨膜铁转运蛋白。我们假设，在铁超载的情况下，这种假定的转运蛋白DMT2介导肝脏铁的积累。这一假设得到了以前的报告和我的初步数据的支持。因此，我的直接目标是分离这种候选转运蛋白DMT2，以更好地了解正常和疾病状态下的铁代谢和调控。为此，我将把我以前使用过的表达克隆技术与我目前工作的实验室生成的小鼠模型分析结合起来。在KO1的支持下，关于肝铁运输的工作将在哈佛医学院和霍华德休斯医学研究所儿童医院安德鲁斯博士实验室提供的优秀环境中进行。她是老鼠分子遗传学和铁代谢医学意义方面的专家。她的实验室、合作者和当地社区的同事将帮助我发展各种方法的技能，包括转基因小鼠技术。我的研究生涯曾因在日本的教学工作而中断。通过辞去我在那里的职位，我已经完全承诺要建立一个独立的研究科学家的职业生涯。NIDDK对KO1的支持将是实现这一目标的垫脚石。这个项目将在一个良好的培训环境中进行，这将培养我的长期职业目标，了解金属离子在健康和疾病中的作用。

I have been intrigued by the enormous importance of metal-ions as essential cofactors for many different biological processes, including gene regulation, free radical homeostasis, and innumerable other catalytic reactions. DMT1 (previously known as DCT1), which I recently cloned is a transmembrane transporter that accepts a variety of transition metal ions. Naturally occurring mutants in DMT1 have provided compelling evidence that it plays a major role in intestinal and bone marrow iron uptake. However, as I describe in the Research Plan section, we hypothesize that there must exist at least one additional transmembrane iron transporter that is different from DMT1. We postulate that this putative transporter, DMT2, mediates liver iron accumulation in the setting of iron overload. This hypothesis is supported by previous reports and my preliminary data. Therefore, my immediate objective is to isolate this candidate transporter, DMT2, to better understand iron metabolism and regulation in normal and disease states. To do this, I will combine expression cloning technology that I have used previously along with analysis of mouse models generated in the laboratory where I am currently working. The work under KO1 support on liver iron transport will be performed in the outstanding environment provided by Harvard Medical School and the Howard Hughes Medical Institute in the laboratory of Dr. Andrews at Children's Hospital. She is an expert in mouse molecular genetics and the medical implications of iron metabolism. Her laboratory, collaborators and colleagues in the local community will help me to develop the skills in a variety of methodologies, including transgenic mouse technology. My research career had been interrupted previously by my teaching obligations in Japan. By resigning from my post there, I have made a total commitment to establish an independent career as a research scientist. This KO1 support from NIDDK will be a stepping stone toward that goal. The proposed project will be carried out in a superb training environment which will nurture my long-term career goal to understand the roles of metal-ions in health and disease.