Document Type
Article
Publication Date
12-2023
Publisher
American Society for Cell Biology
Source Publication
Molecular Biology of the Cell
Source ISSN
1059-1524
Original Item ID
DOI: 10.1091/mbc.E23-04-0132
Abstract
Located in the central protuberance region of the mitoribosome and mitospecific mL38 proteins display homology to PEBP (Phosphatidylethanolamine Binding Protein) proteins, a diverse family of proteins reported to bind anionic substrates/ligands and implicated in cellular signaling and differentiation pathways. In this study, we have performed a mutational analysis of the yeast mitoribosomal protein MrpL35/mL38 and demonstrate that mutation of the PEBP-invariant ligand binding residues Asp(D)232 and Arg(R)288 impacted MrpL35/mL38’s ability to support OXPHOS-based growth of the cell. Furthermore, our data indicate these residues exist in a functionally important charged microenvironment, which also includes Asp(D)167 of MrpL35/mL38 and Arg(R)127 of the neighboring Mrp7/bL27m protein. We report that mutation of each of these charged residues resulted in a strong reduction in OXPHOS complex levels that was not attributed to a corresponding inhibition of the mitochondrial translation process. Rather, our findings indicate that a disconnect exists in these mutants between the processes of mitochondrial protein translation and the events required to ensure the competency and/or availability of the newly synthesized proteins to assemble into OXPHOS enzymes. Based on our findings, we postulate that the PEBP-homology domain of MrpL35/mL38, together with its partner Mrp7/bL27m, form a key regulatory region of the mitoribosome.
Recommended Citation
Box, Jodie M.; Anderson, Jessica M.; and Stuart, Rosemary A., "Mutation of the PEBP-like Domain of the Mitoribosomal MrpL35/mL38 Protein Results in Production of Nascent Chains with Impaired Capacity to Assemble into OXPHOS Complexes" (2023). Biological Sciences Faculty Research and Publications. 966.
https://epublications.marquette.edu/bio_fac/966
Comments
Published version. Molecular Biology of the Cell, Vol. 34, No. 13 (December 2023). DOI. © 2023 American Society for Cell Biology. Used with permission.