Physiological role of polyamines and regulation of their cellular contents

多胺（腐胺、亚精胺和精胺）在细胞增殖和分化中起着重要作用。研究了多胺的生理作用及其对细胞含量的调节。1)在大肠杆菌中鉴定出5个“多胺调节”（polyamine modulon）基因，多胺在翻译水平上增强其表达，参与维持细胞活力。2)为了阐明多胺对神经功能的作用，鉴定了精胺和伊芬普罗地尔在NMDA受体R结构域上的结合位点，并阐明了这些化合物结合后R结构域的结构变化。丙烯醛，一种多胺代谢物，被发现与中风后的神经变性有关。探讨了丙烯醛对细胞的毒性作用机制。4)阐明了两种腐胺转运系统在大肠杆菌中的生理作用。

Polyamines (putrescine, spermidine and spermine) play important roles in cell proliferation and differentiation. The physiological role of polyamines and regulation of their cellular contents were examined. 1) Five genes were identified as members of "polyamine modulon", whose expression is enhanced by polyamines at the level of translation, and were involved in maintenance of cell viability in Escherichia coli. 2) For elucidation of the role of polyamines on neural functions, spermine and ifenprodil binding sites on R domains of NMDA receptors were identified and the structural change of R domains by binding of these compounds were elucidated. Acrolein, a polyamine metabolite, was found to be involved in neurodegeneration after stroke. Mechanisms of cell toxicity of acrolein were examined. 4) Physiological role of two putrescine transport systems were clarified in E. coli.