Unraveling the functions of type II-prohibitins in Arabidopsis mitochondria
- 591 Downloads
In yeast and mammals, prohibitins (PHBs) are considered as structural proteins that form a scaffold-like structure for interacting with a set of proteins involved in various processes occurring in the mitochondria. The role of PHB in plant mitochondria is poorly understood. In the study, the model organism Arabidopsis thaliana was used to identify the possible roles of type-II PHBs (homologs of yeast Phb2p) in plant mitochondria. The obtained results suggest that the plant PHB complex participates in the assembly of multisubunit complexes; namely, respiratory complex I and enzymatic complexes carrying lipoic acid as a cofactor (pyruvate dehydrogenase, 2-oxoglutarate dehydrogenase and glycine decarboxylase). PHBs physically interact with subunits of these complexes. Knockout of two Arabidopsis type-II prohibitins (AtPHB2 and AtPHB6) results in a decreased abundance of these complexes along with a reduction in mitochondrial acyl carrier proteins. Also, the absence of AtPHB2 and AtPHB6 influences the expression of the mitochondrial genome and leads to the activation of alternative respiratory pathways, namely alternative oxidase and external NADH-dependent alternative dehydrogenases.
KeywordsArabidopsis High-molecular-weight complexes Lipoic acid Mitochondria Prohibitins Respiratory chain
This study was supported by Grants N30111932/4116 and NN303561039 funded by the Ministry of Science and Higher Education.
Conflict of interest
The authors declare that they have no conflict of interest.
- Artal-Sanz M, Tsang WY, Willems EM, Grivell LA, Lemire BD, van der Spek H, Nijtmans LG (2003) The mitochondrial prohibitin complex is essential for embryonic viability and germline function in Caenorhabditis elegans. J Biol Chem 278:32091–32099. doi: 10.1074/jbc.M304877200 CrossRefPubMedGoogle Scholar
- Back JW et al. (2002) A structure for the yeast prohibitin complex: structure prediction and evidence from chemical crosslinking and mass spectrometry protein science: a publication of the Protein Society. 11: 2471–2478. doi: 10.1110/ps.0212602Google Scholar
- Christians MJ, Larsen PB (2007) Mutational loss of the prohibitin AtPHB3 results in an extreme constitutive ethylene response phenotype coupled with partial loss of ethylene-inducible gene expression in Arabidopsis seedlings. J Exp Bot 58:2237–2248. doi: 10.1093/jxb/erm086 CrossRefPubMedGoogle Scholar
- Kwasniak M, Majewski P, Skibior R, Adamowicz A, Czarna M, Sliwinska E, Janska H (2013) Silencing of the nuclear RPS10 gene encoding mitochondrial ribosomal protein alters translation in Arabidopsis mitochondria. Plant Cell 25:1855–1867. doi: 10.1105/tpc.113.111294 CrossRefPubMedCentralPubMedGoogle Scholar
- Piechota J, Kolodziejczak M, Juszczak I, Sakamoto W, Janska H (2010) Identification and characterization of high molecular weight complexes formed by matrix AAA proteases and prohibitins in mitochondria of Arabidopsis thaliana. J Biol Chem 285:12512–12521. doi: 10.1074/jbc.M109.063644 CrossRefPubMedCentralPubMedGoogle Scholar