脱镁叶绿酸a单加氧酶与叶绿素降解

Pheophorbide a monooxygenase and chlorophyll degradation

近年来叶绿素降解的分子调控机制颇受关注,脱镁叶绿酸a单加氧酶(PaO)作为催化叶绿素卟啉环开环成为四元线性吡咯衍生物的关键酶,成为研究的焦点。本文从PaO的结构与生理功能出发,着重介绍了近期在PaO表达调控方面的最新研究进展,包括PaO突变体中叶绿素降解的反馈机制;去磷酸化作用与PaO的活性调节;非黄化突变体AtNYE1基因、蛋白激酶基因rlpk2、持绿突变体基因sgr的表达与PaO活性之间的关系,并且简要归纳了PaO研究的发展过程与趋势、存在的问题和争议。

Much attention has been paid to molecular regulation of chlorophyll breakdown in recent years. The pheophorbide a monooxygenase （PaO） is the key enzyme in the oxygenolytic cleavage of the macrocyclic porphyrin ring of chlorophyll to form linear tetrapyrrole derivative. In this paper, based on the structure and physiological function, the recent progress in the studies on PaO was emphasized, including the feedback mechanism of chlorophyll degradation in PaO mutant, the dephosphorylation and activity regulation of PaO, and the relationship between PaO activities and gene expressions of AtNYEI of nonyellowing mutant, rlpk2 of protein kinase and sgr of stay-green mutant. The development, problems and disputes of the research of PaO were also summarized.