植物中的线粒体和叶绿体是包含遗传信息的半自主性细胞器,它们的功能同时受到自身和细胞核遗传信息共同的调控.三角状五肽(PPR)蛋白是一类含有三角状五肽重复结构的核基因组编码蛋白的大家族.植物中的PPR蛋白通常定位于线粒体或叶绿体中,并对这些细胞器基因组转录的RNA进行编辑和修饰,参与许多重要的组织发生和器官形成过程的调控,同时也参与了植物对内外环境变化过程的响应等.因此,PPR是研究植物中细胞器功能和核质互作机制的热点.依据PPR蛋白基序的种类和排列方式,将植物中的PPR分为两大亚类:P 类和PLS类.P 类由经典的35个氨基酸基序排列组成,主要参与细胞器基因的转录调控;短的S、长的L和经典的P基序排列组成PLS亚族,主要对细胞器基因转录的RNA进行编辑修饰.本文主要从PPR蛋白的结构、亚细胞定位以及在线粒体和叶绿体中的功能等方面着手阐述植物PPR蛋白在叶绿体和线粒体基因组转录和加工过程中的作用以及与植物发育之间的关系,并对研究中存在的一些问题提出设想.%Mitochondria and chloroplasts are semi-autonomous organelles in plants. Their functions are regulated by both their own and the nuclear information. Pentatricopeptide repeat(PPR) proteins are a large nuclear genome encoded protein family with a tri-angular five peptide repeat structure. PPRs are usually sub-located in plant mitochondria and chloroplasts,and participate in organ-elle genome transcribed RNA editing and modifications. The functions of PPRs are varied in different plant tissue and organ develop-ment processes,and also in the responses to changes of internal and external environment events. Therefore,the research on PPRs is one of the hotspots in the study of organelle functions and cytoplasm-nuclear interactions in plants. PPRs are mainly divided into two major categories,class P and class PLS,based on the types of PPR motif and their arrangement.In this study,we summarize the research progress on the functions of PPRs in plants,mainly focus on the protein structure characteristics,the sub-cellular localiza-tion of PPRs,and the functions of PPRs in mitochondria and chloroplasts to decipher the roles of PPRs in mitochondria and chloro-plasts RNA editing and processing, and their regulations with plant development. Some prospects about the problems existing in present studies are also proposed.
展开▼
