Mitochondrial DNA polymerase gamma is expressed and translated in the absence of mitochondrial DNA maintenance and replication.
Nucleic Acids Res
; 24(14): 2753-9, 1996 Jul 15.
Article
en En
| MEDLINE
| ID: mdl-8759007
Mitochondria are essential organelles in all eukaryotic cells where cellular ATP is generated through the process of oxidative phosphorylation. Protein components of the respiratory assembly are gene products of both mitochondrial and nuclear genes. The mitochondrial genome itself encodes several protein and nucleic acid components required for such oxidative phosphorylative processes, but the vast majority of genes encoding respiratory chain components are nuclear. Similarly, the processes of replication and transcription of mitochondrial DNA rely exclusively upon RNA and protein species encoded by nuclear genes. We have analyzed two key nuclear-encoded proteins involved in mitochondrial DNA replication and transcription as a function of the presence or absence of mitochondrial DNA. Mitochondrial DNA polymerase (DNA polymerase gamma), the nuclear-encoded enzyme which synthesizes mtDNA, is expressed and translated in cells devoid of mitochondrial DNA itself. In contrast, mitochondrial transcription factor A protein levels are tightly linked to the mtDNA status of the cell. These results demonstrate that the DNA polymerase gamma protein is stable in the absence of mitochondrial DNA, and that there appears to be no regulatory mechanism present in these cells to alter levels of this protein in the complete absence of mitochondrial DNA. Alternatively, it is possible that this enzyme plays an additional, as yet undefined, role in the cell, thereby mandating its continued production.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Biosíntesis de Proteínas
/
ADN Mitocondrial
/
Proteínas Nucleares
/
Transactivadores
/
Proteínas de Xenopus
/
Proteínas Mitocondriales
/
Proteínas de Unión al ADN
/
ADN Polimerasa III
/
Mitocondrias
Límite:
Humans
Idioma:
En
Revista:
Nucleic Acids Res
Año:
1996
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Reino Unido