Mitochondrial ribosome bL34 mutants present diminished translation of cytochrome c oxidase subunits

Author(s)

Guedes-Monteiro, Raquel Fonseca ; Ferreira-Junior, Jose Ribamar ; Bleicher, Lucas ; Nobrega, Francisco G. ; Barrientos, Antoni ; Barros, Mario H.

• Document type: Journal article
• Source: Cell Biology International; v. 42, n. 6, p. 13-pg., 2018-06-01.

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. (AU)

• FAPESP's process: 13/09482-8 - Saccharomyces cerevisiae as a model for mitochondrial translation studies
• Grantee: Mario Henrique de Barros
• Support Opportunities: Regular Research Grants
• FAPESP's process: 11/18892-0 - Characterization of mitochondrial gene products with unknown function in Saccharomyces cerevisiae.
• Grantee: Raquel Fonseca Guedes Monteiro
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 13/07937-8 - Redoxome - Redox Processes in Biomedicine
• Grantee: Ohara Augusto
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC