Kang Ji Hyun, Lee Dong Wook
Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, 61186, South Korea.
Department of Bioenergy Science and Technology, Chonnam National University, Gwangju, 61186, South Korea.
Plant Cell Rep. 2024 Dec 26;44(1):14. doi: 10.1007/s00299-024-03409-2.
Chloroplasts, distinctive subcellular organelles found exclusively in plant species, contain three membranes: the outer, inner, and thylakoid membranes. They also have three soluble compartments: the intermembrane space, stroma, and thylakoid lumen. Accordingly, delicate sorting mechanisms are required to ensure proper protein targeting to these sub-chloroplast compartments. Except for most outer membrane proteins, chloroplast interior proteins possess N-terminal cleavable transit peptides as primary import signals. After the cleavage of transit peptides, which occurs during or after import into chloroplasts, the inner and thylakoid membrane proteins, as well as stromal and thylakoid luminal proteins, are further sorted based on additional targeting signals. In this review, we aim to recapitulate the mechanisms by which proteins are targeted to chloroplasts and subsequently sorted into sub-chloroplast compartments, with a focus on the design principles of sorting signals present in chloroplast proteins.
叶绿体是仅在植物物种中发现的独特亚细胞器，它含有三层膜：外膜、内膜和类囊体膜。它们还有三个可溶性区室：膜间隙、基质和类囊体腔。因此，需要精密的分选机制来确保蛋白质正确靶向这些叶绿体亚区室。除了大多数外膜蛋白外，叶绿体内部蛋白具有可在N端切割的转运肽作为主要的导入信号。转运肽在导入叶绿体的过程中或之后被切割，之后，内膜蛋白、类囊体膜蛋白以及基质蛋白和类囊体腔蛋白会根据其他靶向信号进一步分选。在这篇综述中，我们旨在概述蛋白质靶向叶绿体并随后被分选到叶绿体亚区室的机制，重点是叶绿体蛋白中存在的分选信号的设计原则。
