Piechota Janusz, Bereza Monika, Sokołowska Aleksandra, Suszyński Kondrad, Lech Karolina, Jańska Hanna
Department of Biotechnology, University of Wroclaw, F. Juliot-Curie 14a, 50-383, Wroclaw, Poland,
Plant Mol Biol. 2015 Jun;88(3):249-67. doi: 10.1007/s11103-015-0320-3. Epub 2015 Apr 21.
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.
在酵母和哺乳动物中， prohibitin蛋白（PHB）被认为是一种结构蛋白，可形成支架样结构，用于与参与线粒体中各种过程的一组蛋白质相互作用。PHB在植物线粒体中的作用尚不清楚。在这项研究中，使用模式生物拟南芥来确定II型PHB（酵母Phb2p的同源物）在植物线粒体中的可能作用。获得的结果表明，植物PHB复合物参与多亚基复合物的组装；即呼吸复合物I和以硫辛酸为辅因子的酶复合物（丙酮酸脱氢酶、2-氧代戊二酸脱氢酶和甘氨酸脱羧酶）。PHB与这些复合物的亚基发生物理相互作用。敲除两个拟南芥II型prohibitin蛋白（AtPHB2和AtPHB6）会导致这些复合物的丰度降低，同时线粒体酰基载体蛋白减少。此外，AtPHB2和AtPHB6的缺失会影响线粒体基因组的表达，并导致替代呼吸途径的激活，即交替氧化酶和外部NADH依赖性替代脱氢酶。
