Cookies Disclaimer

OK Our site saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing our website without changing the browser settings you grant us permission to store that information on your device.

Publication

Bibliographic Data

  • Authors: Kukat, C.,Wurm, C.A.,Spahr, H.,Falkenberg, M.,Larsson, N.-G. and Jakobs, S.
  • Title: Super-resolution microscopy reveals that mammalian mitochondrial nucleoids have a uniform size and frequently contain a single copy of mtDNA
  • Journal: PNAS
  • Volume: 108
  • Issue: 33
  • Volume: 13534-13539
  • DOI: 10.1073/pnas.1109263108

Abstract

Mammalian mtDNA is packaged in DNA-protein complexes denoted mitochondrial nucleoids. The organization of the nucleoid is a very fundamental question in mitochondrial biology and will determine tissue segregation and transmission of mtDNA. We have used a combination of stimulated emission depletion microscopy, enabling a resolution well below the diffraction barrier, and molecular biology to study nucleoids in a panel of mammalian tissue culture cells. We report that the nucleoids labeled with antibodies against DNA, mitochondrial transcription factor A (TFAM), or incorporated BrdU, have a defined, uniform mean size of similar to 100 nm in mammals. Interestingly, the nucleoid frequently contains only a single copy of mtDNA (average similar to 1.4 mtDNA molecules per nucleoid). Furthermore, we show by molecular modeling and volume calculations that TFAM is a main constituent of the nucleoid, besides mtDNA. These fundamental insights into the organization of mtDNA have broad implications for understanding mitochondrial dysfunction in disease and aging.