Single organelle function and organization as estimated from Arabidopsis mitochondrial proteomics

Fuchs P, Rugen N, Carrie C, Elsässer M, Finkemeier I, Giese J, Hildebrandt TM, Kühn K, Maurino VG, Ruberti C, Schallenberg-Rüdinger M, Steinbeck J, Braun HP, Eubel H, Meyer EH, Müller-Schüssele SJ, Schwarzländer M

Research article (journal) | Peer reviewed

Abstract

Mitochondria host vital cellular functions, including oxidative phosphorylation and co-factor biosynthesis, which are reflected in their proteome. At the cellular level plant mitochondria are organized into hundreds of discrete functional entities, which undergo dynamic fission and fusion. It is the individual organelle that operates in the living cell, yet biochemical and physiological assessments have exclusively focused on the characteristics of large populations of mitochondria. Here, we explore the protein composition of an individual average plant mitochondrion to deduce principles of functional and structural organisation. We perform proteomics on purified mitochondria from cultured heterotrophic Arabidopsis cells with intensity-based absolute quantification and scale the dataset to the single organelle based on criteria that are justified by experimental evidence and theoretical considerations. We estimate that a total of 1.4 million protein molecules make up a single Arabidopsis mitochondrion on average. Copy numbers of the individual proteins span five orders of magnitude, ranging from >40,000 for Voltage-Dependent Anion Channel 1 (VDAC1) to sub-stoichiometric copy numbers, i.e. less than a single copy per single mitochondrion, for several pentatricopeptide repeat (PPR) proteins that modify mitochondrial transcripts. For our analysis, we consider the physical and chemical constraints of the single organelle and discuss prominent features of mitochondrial architecture, protein biogenesis, oxidative phosphorylation, metabolism, antioxidant defence, genome maintenance, gene expression and dynamics. While assessing the limitations of our considerations, we exemplify how our understanding of biochemical function and structural organization of plant mitochondria can be connected in order to obtain global and specific insights into how organelles work.

Details about the publication

JournalThe Plant journal (Plant J)
Volume1
StatusPublished
Release year2020
Language in which the publication is writtenEnglish
DOI10.1111/tpj.14534
Link to the full texthttps://onlinelibrary.wiley.com/doi/abs/10.1111/tpj.14534

Authors from the University of Münster

Elsässer, Marlene
Professorship for general botany with the focus on plant/environment interactions (Prof. Schwarzländer)
Finkemeier, Iris
Professorship for Plant Physiology (Prof. Finkemeier)
Giese, Jonas
Professorship for Plant Physiology (Prof. Finkemeier)
Ruberti, Cristina
Professorship for general botany with the focus on plant/environment interactions (Prof. Schwarzländer)
Schwarzländer, Markus
Professorship for general botany with the focus on plant/environment interactions (Prof. Schwarzländer)
Steinbeck, Maren Janina
Plant Biochemistry and Biotechnology - Group Prof. Michael Hippler