Mitochondrial ribosome bL34 mutants present diminished translation of cytochrome c oxidase subunits. (7th December 2017)

• Record Type: Journal Article
• Authors: Guedes‐Monteiro, Raquel Fonseca; Ferreira‐Junior, José Ribamar; Bleicher, Lucas; Nóbrega, Francisco G.; Barrientos, Antoni; Barros, Mario H.
• Other Names: de Souza‐Pinto Nadja Cristhina guestEditor.
• Is Part Of: Cell biology international. Volume 42:Number 6(2018)
• Page Start: 630
• Page End: 642
• Publication Date: 2017-12-07
• Subjects: cytochrome c oxidase -- mitoribosome -- mtDNA -- respiratory chain -- translation -- yeast; Cytology -- Periodicals; Cells -- Periodicals; 571.605
• DOI: 10.1002/cbin.10913
• Languages: English
• ISSNs: 1065-6995

Abstract

Abstract: Saccharomyces cerevisiae mitoribosomes are specialized in the translation of a few number of highly hydrophobic membrane proteins, components of the oxidative phosphorylation system. Mitochondrial characteristics, such as the membrane system and its redox state driven mitoribosomes evolution through great diversion from their bacterial and cytosolic counterparts. Therefore, mitoribosome presents a considerable number of mitochondrial‐specific proteins, as well as new protein extensions. In this work we characterize temperature sensitive mutants of the subunit bL34 present in the 54S large subunit. Although bL34 has bacterial homologs, in yeast it has a long 65 aminoacids mitochondrial N‐terminal addressing sequence, here we demonstrate that it can be replaced by the mitochondrial addressing sequence of Neurospora crassa ATP9 gene. The bL34 temperature sensitive mutants present lowered translation of mitochondrial COX1 and COX3, which resulted in reduced cytochrome c oxidase activity and respiratory growth deficiency. The sedimentation properties of bL34 in sucrose gradients suggest that similarly to its bacterial homolog, bL34 is also a later participant in the process of mitoribosome biogenesis.