Abstract
To function as a metabolic hub, plant mitochondria have to exchange a wide variety of metabolic intermediates as well as inorganic ions with the cytosol. As identified by proteomic profiling or as predicted by MU-LOC, a newly developed bioinformatics tool, Arabidopsis thaliana mitochondria contain 128 or 143 different transporters, respectively. The largest group is the mitochondrial carrier family, which consists of symporters and antiporters catalyzing secondary active transport of organic acids, amino acids, and nucleotides across the inner mitochondrial membrane. An impressive 97% (58 out of 60) of all the known mitochondrial carrier family members in Arabidopsis have been experimentally identified in isolated mitochondria. In addition to many other secondary transporters, Arabidopsis mitochondria contain the ATP synthase transporters, the mitochondria protein translocase complexes (responsible for protein uptake across the outer and inner membrane), ATP-binding cassette (ABC) transporters, and a number of transporters and channels responsible for allowing water and inorganic ions to move across the inner membrane driven by their transmembrane electrochemical gradient. A few mitochondrial transporters are tissue-specific, development-specific, or stress-response specific, but this is a relatively unexplored area in proteomics that merits much more attention.
Highlights
Eukaryotic multicellular organisms need to exchange energy, matter, and information between the environment and their cells, between their cells, and within their cells
The largest protein groups in the identified proteome of both Arabidopsis and potato mitochondria are related to energy and metabolism, with around 150 and 200 proteins, respectively; protein fate, protein synthesis, and RNA processing are each represented by approximately 100 proteins, while transport has around 50 proteins [8]
The outer mitochondrial membrane (OMM) in isolated mitochondria behaves as if it is freely permeable to small molecules, so the voltage-dependent anion channel (VDAC) do not appear to be actively gated, but it is possible that porin is involved in tRNA transport [11,12,42]
Summary
Eukaryotic multicellular organisms need to exchange energy, matter, and information between the environment and their cells, between their cells, and within their cells To perform these tasks, they need a diverse array of specialized proteins to move ions and molecules across the biological membranes, which delimit the cells and the subcellular compartmentation. To grow and divide the mitochondria one needs to import the vast majority of its proteins as well as some tRNAs and rRNA [8,9,10] All of these processes require the presence of many different transporters in the mitochondria. The mitochondrial transportome was comprehensively reviewed by Lee and Millar [13] It is the purpose of this review first to compile a list of the transporters identified by proteomic profiling of isolated plant mitochondria. For each transporter class or family, we will briefly discuss the properties of the transporters present in plant mitochondria
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
