title: A Role for the Mitochondrial Protein Mrpl44 in Maintaining OXPHOS Capacity.
abstract: We identified Mrpl44 in a search for mammalian proteins that contain RNase III domains. This protein was previously found in association with the mitochondrial ribosome of bovine liver extracts. However, the precise Mrpl44 localization had been unclear. Here, we show by immunofluorescence microscopy and subcellular fractionation that Mrpl44 is localized to the matrix of the mitochondria. We found that it can form multimers, and confirm that it is part of the large subunit of the mitochondrial ribosome. By manipulating its expression, we show that Mrpl44 may be important for regulating the expression of mtDNA-encoded genes. This was at the level of RNA expression and protein translation. This ultimately impacted ATP synthesis capability and respiratory capacity of cells. These findings indicate that Mrpl44 plays an important role in the regulation of the mitochondrial OXPHOS capacity.
authors.affiliation: Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia; Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia; St. Vincent's Institute of Medical Research, Fitzroy, VIC, Australia.
authors.forename: Janet H C
authors.initials: JH
authors.lastname: Yeo
authors.affiliation: St. Vincent's Institute of Medical Research, Fitzroy, VIC, Australia.
authors.forename: Jarrod P J
authors.initials: JP
authors.lastname: Skinner
authors.affiliation: Murdoch Childrens Research Institute, Parkville, VIC, Australia; Department of Paediatrics, University of Melbourne, Parkville VIC, Australia.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Bird
authors.affiliation: Department of Biochemistry, La Trobe University, Bundoora, VIC, Australia.
authors.forename: Luke E
authors.initials: LE
authors.lastname: Formosa
authors.affiliation: Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia; Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia.
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Zhang
authors.affiliation: Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia; Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia.
authors.forename: Ruth M
authors.initials: RM
authors.lastname: Kluck
authors.affiliation: Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia; Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia.
authors.forename: Gabrielle T
authors.initials: GT
authors.lastname: Belz
authors.affiliation: St. Vincent's Institute of Medical Research, Fitzroy, VIC, Australia; Department of Medicine (St Vincent's), University of Melbourne, Parkville VIC, Australia.
authors.forename: Mark M W
authors.initials: MM
authors.lastname: Chong
mesh_terms: D000255:Adenosine Triphosphate / Q000096:biosynthesis; D000818:Animals; D002417:Cattle; D002460:Cell Line; D004272:DNA, Mitochondrial / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D057809:HEK293 Cells; D006801:Humans; D051379:Mice; D008930:Mitochondria, Liver / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000069396:Mitochondrial Ribosomes / Q000378:metabolism; D041681:NIH 3T3 Cells; D010085:Oxidative Phosphorylation; D010101:Oxygen Consumption; D055503:Protein Multimerization; D043244:Ribonuclease III / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012269:Ribosomal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D004272:DNA, Mitochondrial; D024101:Mitochondrial Proteins; D012269:Ribosomal Proteins; D000255:Adenosine Triphosphate; D043244:Ribonuclease III