Another function for the mitochondrial ribosomal RNA: protein folding.
Specialized proteins known as molecular chaperones bind transiently to non-native conformational states of proteins and protein complexes to promote transition to a biologically active conformation. Recently, it was demonstrated in vitro that proteins do not uniquely possess this activity. We show that mitochondrial 12S and 16S ribosomal RNA can fold chemically denatured proteins and reactivate heat-induced aggregated proteins in vitro. This chaperone action is ATP-independent. The specific secondary structure of the mitochondrial rRNA is critical to its folding activity. Furthermore, mutant mitochondrial 16S rRNA from aged cardiac muscle cells lacked this activity. We propose that mitochondrial 12S and 16S ribosomal RNA may play an important role in protein folding in mitochondria.
Sulijoadikusumo
I
I
Division of Endocrinology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA.
Horikoshi
N
N
Usheva
A
A
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001517:Coleoptera; D004272:DNA, Mitochondrial / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry / Q000378:metabolism; D015246:Deoxyribonuclease EcoRI / Q000737:chemistry / Q000378:metabolism*; D004798:Enzymes / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008156:Luciferases / Q000737:chemistry / Q000378:metabolism; D008291:Malate Dehydrogenase / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D008929:Mitochondria, Heart / Q000201:enzymology; D018832:Molecular Chaperones / Q000378:metabolism; D009690:Nucleic Acid Conformation; D011489:Protein Denaturation; D017510:Protein Folding; D012313:RNA / Q000737:chemistry / Q000378:metabolism*; D000077278:RNA, Mitochondrial; D012335:RNA, Ribosomal / Q000737:chemistry / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000737:chemistry / Q000378:metabolism*; D013552:Swine; D014158:Transcription, Genetic; D014764:Viral Proteins
D004272:DNA, Mitochondrial; D004798:Enzymes; D018832:Molecular Chaperones; D000077278:RNA, Mitochondrial; D012335:RNA, Ribosomal; D012336:RNA, Ribosomal, 16S; C075526:RNA, ribosomal, 12S; D014764:Viral Proteins; D012313:RNA; D000255:Adenosine Triphosphate; D008291:Malate Dehydrogenase; D008156:Luciferases; C062210:bacteriophage T7 RNA polymerase; D012321:DNA-Directed RNA Polymerases; D015246:Deoxyribonuclease EcoRI