The ATP-dependent PIM1 protease is required for the expression of intron-containing genes in mitochondria.
The ATP-dependent PIM1 protease, a Lon-like protease localized in the mitochondrial matrix, is required for mitochondrial genome integrity in yeast. Cells lacking PIM1 accumulate lesions in the mitochondrial DNA (mtDNA) and therefore lose respiratory competence. The identification of a multicopy suppressor, which stabilizes mtDNA in the absence of PIM1, enabled us to characterize novel functions of PIM1 protease during mitochondrial biogenesis. The synthesis of mitochondrially encoded cytochrome c oxidase subunit I (CoxI) and cytochrome b (Cob) is impaired in pim1 mutants containing mtDNA. PIM1-mediated proteolysis is required for the translation of mature COXI mRNA. Moreover, deficiencies in the splicing of COXI and COB transcripts, which appear to be restricted to introns encoding mRNA maturases, were observed in cells lacking the PIM1 gene. Transcripts of COXI and COB genes harboring multiple introns are degraded in the absence of PIM1. These results establish multiple, essential functions of the ATP-dependent PIM1 protease during mitochondrial gene expression.
van Dyck
L
L
Institut für Physiologische Chemie der Universität München, 80336 München, Germany. Langer@bio.med.uni-muenchen.de
Neupert
W
W
Langer
T
T
D049069:ATP-Dependent Proteases; D000255:Adenosine Triphosphate / Q000502:physiology*; D003573:Cytochrome b Group / Q000096:biosynthesis* / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics*; D003576:Electron Transport Complex IV / Q000096:biosynthesis* / Q000235:genetics; D004722:Endoribonucleases / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000502:physiology*; D015966:Gene Expression Regulation, Fungal; D016153:Genes, Suppressor; D007438:Introns / Q000235:genetics*; D008928:Mitochondria / Q000378:metabolism; D024101:Mitochondrial Proteins; D009713:Nucleotidyltransferases / Q000378:metabolism; D012322:RNA Precursors / Q000378:metabolism; D012326:RNA Splicing / Q000502:physiology*; D012331:RNA, Fungal / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D012697:Serine Endopeptidases / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic
D003573:Cytochrome b Group; D004272:DNA, Mitochondrial; D005656:Fungal Proteins; D024101:Mitochondrial Proteins; D012322:RNA Precursors; D012331:RNA, Fungal; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; D000255:Adenosine Triphosphate; D003576:Electron Transport Complex IV; D009713:Nucleotidyltransferases; C034038:mRNA maturase; D004722:Endoribonucleases; D049069:ATP-Dependent Proteases; C085155:PIM1 protein, S cerevisiae; D012697:Serine Endopeptidases