Abstract
The accessory subunit of mitochondrial DNA polymerase γ, POLGβ, functions as a processivity factor in vitro. Here we show POLGβ has additional roles in mitochondrial DNA metabolism. Mitochondrial DNA is arranged in nucleoprotein complexes, or nucleoids, which often contain multiple copies of the mitochondrial genome. Gene-silencing of POLGβ increased nucleoid numbers, whereas overexpression of POLGβ reduced the number and increased the size of mitochondrial nucleoids. Both increased and decreased expression of POLGβ altered nucleoid structure and precipitated a marked decrease in 7S DNA molecules, which form short displacement-loops on mitochondrial DNA. Recombinant POLGβ preferentially bound to plasmids with a short displacement-loop, in contrast to POLGα. These findings support the view that the mitochondrial D-loop acts as a protein recruitment centre, and suggest POLGβ is a key factor in the organization of mitochondrial DNA in multigenomic nucleoprotein complexes.
| Original language | English |
|---|---|
| Article number | gkp614 |
| Pages (from-to) | 5701-5713 |
| Number of pages | 13 |
| Journal | Nucleic acids research |
| Volume | 37 |
| Issue number | 17 |
| DOIs | |
| Publication status | Published - Jul 22 2009 |
| Externally published | Yes |
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All Science Journal Classification (ASJC) codes
- Genetics
Cite this
The accessory subunit of mitochondrial DNA polymerase γ determines the DNA content of mitochondrial nucleoids in human cultured cells. / Di Re, M.; Sembongi, H.; He, J.; Reyes, A.; Yasukawa, Takehiro; Martinsson, P.; Bailey, L. J.; Goffart, S.; Boyd-kirkup, J. D.; Wong, T. S.; Fersht, A. R.; Spelbrink, J. N.; Holt, I. J.
In: Nucleic acids research, Vol. 37, No. 17, gkp614, 22.07.2009, p. 5701-5713.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The accessory subunit of mitochondrial DNA polymerase γ determines the DNA content of mitochondrial nucleoids in human cultured cells
AU - Di Re, M.
AU - Sembongi, H.
AU - He, J.
AU - Reyes, A.
AU - Yasukawa, Takehiro
AU - Martinsson, P.
AU - Bailey, L. J.
AU - Goffart, S.
AU - Boyd-kirkup, J. D.
AU - Wong, T. S.
AU - Fersht, A. R.
AU - Spelbrink, J. N.
AU - Holt, I. J.
PY - 2009/7/22
Y1 - 2009/7/22
N2 - The accessory subunit of mitochondrial DNA polymerase γ, POLGβ, functions as a processivity factor in vitro. Here we show POLGβ has additional roles in mitochondrial DNA metabolism. Mitochondrial DNA is arranged in nucleoprotein complexes, or nucleoids, which often contain multiple copies of the mitochondrial genome. Gene-silencing of POLGβ increased nucleoid numbers, whereas overexpression of POLGβ reduced the number and increased the size of mitochondrial nucleoids. Both increased and decreased expression of POLGβ altered nucleoid structure and precipitated a marked decrease in 7S DNA molecules, which form short displacement-loops on mitochondrial DNA. Recombinant POLGβ preferentially bound to plasmids with a short displacement-loop, in contrast to POLGα. These findings support the view that the mitochondrial D-loop acts as a protein recruitment centre, and suggest POLGβ is a key factor in the organization of mitochondrial DNA in multigenomic nucleoprotein complexes.
AB - The accessory subunit of mitochondrial DNA polymerase γ, POLGβ, functions as a processivity factor in vitro. Here we show POLGβ has additional roles in mitochondrial DNA metabolism. Mitochondrial DNA is arranged in nucleoprotein complexes, or nucleoids, which often contain multiple copies of the mitochondrial genome. Gene-silencing of POLGβ increased nucleoid numbers, whereas overexpression of POLGβ reduced the number and increased the size of mitochondrial nucleoids. Both increased and decreased expression of POLGβ altered nucleoid structure and precipitated a marked decrease in 7S DNA molecules, which form short displacement-loops on mitochondrial DNA. Recombinant POLGβ preferentially bound to plasmids with a short displacement-loop, in contrast to POLGα. These findings support the view that the mitochondrial D-loop acts as a protein recruitment centre, and suggest POLGβ is a key factor in the organization of mitochondrial DNA in multigenomic nucleoprotein complexes.
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U2 - 10.1093/nar/gkp614
DO - 10.1093/nar/gkp614
M3 - Article
VL - 37
SP - 5701
EP - 5713
JO - Nucleic Acids Research
JF - Nucleic Acids Research
SN - 0305-1048
IS - 17
M1 - gkp614
ER -