Published online January 8, 2007
doi:10.1083/jcb.200609158
The Journal of Cell Biology, Vol. 176, No. 2, 141-146
The Rockefeller University Press, 0021-9525 $30.00
© 2007 He et al.
The AAA+ protein ATAD3 has displacement loop binding properties and is involved in mitochondrial nucleoid organization
Jiuya He1,
Chih-Chieh Mao1,
Aurelio Reyes1,
Hiroshi Sembongi1,
Miriam Di Re1,
Caroline Granycome1,
Andrew B. Clippingdale1,
Ian M. Fearnley1,
Michael Harbour1,
Alan J. Robinson1,
Stefanie Reichelt2,
Johannes N. Spelbrink3,
John E. Walker1, and
Ian J. Holt1
1 Medical Research Council Dunn Human Nutrition Unit, Wellcome Trust/Medical Research Council Building, Cambridge CB2 OXY, England, UK
2 Cancer Research UK, Cambridge Research Institute, Cambridge CB2 ORE, England, UK
3 Institute of Medical Technology and Tampere University Hospital, University of Tampere, FI-33014 Tampere, Finland
Correspondence to Ian J. Holt: holt{at}mrc-dunn.cam.ac.uk
Many copies of mammalian mitochondrial DNA contain a short triple-stranded region, or displacement loop (D-loop), in the major noncoding region. In the 35 years since their discovery, no function has been assigned to mitochondrial D-loops. We purified mitochondrial nucleoprotein complexes from rat liver and identified a previously uncharacterized protein, ATAD3p. Localization studies suggested that human ATAD3 is a component of many, but not all, mitochondrial nucleoids. Gene silencing of ATAD3 by RNA interference altered the structure of mitochondrial nucleoids and led to the dissociation of mitochondrial DNA fragments held together by protein, specifically, ones containing the D-loop region. In vitro, a recombinant fragment of ATAD3p bound to supercoiled DNA molecules that contained a synthetic D-loop, with a marked preference over partially relaxed molecules with a D-loop or supercoiled DNA circles. These results suggest that mitochondrial D-loops serve to recruit ATAD3p for the purpose of forming or segregating mitochondrial nucleoids.
J. He and C.-C. Mao contributed equally to this paper.
Abbreviations used in this paper: AGE, agarose gel electrophoresis; D-loop, displacement loop; dsRNA, double-stranded RNA; EMSA, electrophoretic mobility shift assay; mtDNA, mitochondrial DNA; NCR, noncoding region.

CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati What's this?
Related Article
-
Thrown for a D-loop
- Mitch Leslie
J. Cell Biol. 2007 176: 129a.
[Full Text]
[PDF]
This article has been cited by other articles:
-
Kienhofer, J., Haussler, D. J. F., Ruckelshausen, F., Muessig, E., Weber, K., Pimentel, D., Ullrich, V., Burkle, A., Bachschmid, M. M.
(2009). Association of mitochondrial antioxidant enzymes with mitochondrial DNA as integral nucleoid constituents. FASEB J.
23: 2034-2044
[Abstract]
[Full Text]
-
Iacovino, M., Granycome, C., Sembongi, H., Bokori-Brown, M., Butow, R. A., Holt, I. J., Bateman, J. M.
(2009). The conserved translocase Tim17 prevents mitochondrial DNA loss. Hum Mol Genet
18: 65-74
[Abstract]
[Full Text]
-
Rorbach, J., Richter, R., Wessels, H. J., Wydro, M., Pekalski, M., Farhoud, M., Kuhl, I., Gaisne, M., Bonnefoy, N., Smeitink, J. A., Lightowlers, R. N., Chrzanowska-Lightowlers, Z. M.A.
(2008). The human mitochondrial ribosome recycling factor is essential for cell viability. Nucleic Acids Res
36: 5787-5799
[Abstract]
[Full Text]
-
Bogenhagen, D. F., Rousseau, D., Burke, S.
(2008). The Layered Structure of Human Mitochondrial DNA Nucleoids. J. Biol. Chem.
283: 3665-3675
[Abstract]
[Full Text]
-
Hyvarinen, A. K., Pohjoismaki, J. L. O., Reyes, A., Wanrooij, S., Yasukawa, T., Karhunen, P. J., Spelbrink, J. N., Holt, I. J., Jacobs, H. T.
(2007). The mitochondrial transcription termination factor mTERF modulates replication pausing in human mitochondrial DNA. Nucleic Acids Res
35: 6458-6474
[Abstract]
[Full Text]
-
Sembongi, H., Di Re, M., Bokori-Brown, M., Holt, I. J.
(2007). The yeast Holliday junction resolvase, CCE1, can restore wild-type mitochondrial DNA to human cells carrying rearranged mitochondrial DNA. Hum Mol Genet
16: 2306-2314
[Abstract]
[Full Text]
-
Kaufman, B. A., Durisic, N., Mativetsky, J. M., Costantino, S., Hancock, M. A., Grutter, P., Shoubridge, E. A.
(2007). The Mitochondrial Transcription Factor TFAM Coordinates the Assembly of Multiple DNA Molecules into Nucleoid-like Structures. Mol. Biol. Cell
18: 3225-3236
[Abstract]
[Full Text]