scholarly journals Replication Intermediates of the Linear Mitochondrial DNA of Candida parapsilosis Suggest a Common Recombination Based Mechanism for Yeast Mitochondria

2014 ◽  
Vol 289 (33) ◽  
pp. 22659-22670 ◽  
Author(s):  
Joachim M. Gerhold ◽  
Tiina Sedman ◽  
Katarina Visacka ◽  
Judita Slezakova ◽  
Lubomir Tomaska ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Candida Parapsilosis ◽  
Yeast Mitochondria ◽  
Linear Mitochondrial Dna ◽  
Replication Intermediates

A human mitochondrial transcriptional activator can functionally replace a yeast mitochondrial HMG-box protein both in vivo and in vitro

1993 ◽  
Vol 13 (3) ◽  
pp. 1951-1961
Author(s):  
M A Parisi ◽  
B Xu ◽  
D A Clayton
Keyword(s):  
Transcription Factor ◽  
Mitochondrial Dna ◽  
Nuclear Gene ◽  
Transcriptional Activator ◽  
Yeast Mitochondria ◽  
Yeast Protein ◽  
Mitochondrial Transcription ◽  
Mitochondrial Transcription Factor ◽  
Mitochondrial Transcription Factor A

Human mitochondrial transcription factor A is a 25-kDa protein that binds immediately upstream of the two major mitochondrial promoters, thereby leading to correct and efficient initiation of transcription. Although the nature of yeast mitochondrial promoters is significantly different from that of human promoters, a potential functional homolog of the human transcriptional activator protein has been previously identified in yeast mitochondria. The importance of the yeast protein in yeast mitochondrial DNA function has been shown by inactivation of its nuclear gene (ABF2) in Saccharomyces cerevisiae cells resulting in loss of mitochondrial DNA. We report here that the nuclear gene for human mitochondrial transcription factor A can be stably expressed in yeast cells devoid of the yeast homolog protein. The human protein is imported efficiently into yeast mitochondria, is processed correctly, and rescues the loss-of-mitochondrial DNA phenotype in a yeast abf2 strain, thus functionally substituting for the yeast protein. Both human and yeast proteins affect yeast mitochondrial transcription initiation in vitro, suggesting that the two proteins may have a common role in this fundamental process.

The complete mitochondrial DNA sequence of Hansenula wingei reveals new characteristics of yeast mitochondria

1995 ◽  
Vol 28 (1) ◽  
pp. 39-53 ◽  
Author(s):  
Takayuki Sekito ◽  
Kozi Okamoto ◽  
Hiromichi Kitano ◽  
Kazuo Yoshida
Keyword(s):  
Mitochondrial Dna ◽  
Dna Sequence ◽  
Yeast Mitochondria ◽  
Mitochondrial Dna Sequence ◽  
Hansenula Wingei

scholarly journals Human Dna2 Is a Nuclear and Mitochondrial DNA Maintenance Protein

2009 ◽  
Vol 29 (15) ◽  
pp. 4274-4282 ◽  
Author(s):  
Julien P. Duxin ◽  
Benjamin Dao ◽  
Peter Martinsson ◽  
Nina Rajala ◽  
Lionel Guittat ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Dna Replication ◽  
Telomere Maintenance ◽  
Okazaki Fragment Processing ◽  
Biochemical Fractionation ◽  
Mitochondrial Nucleoids ◽  
Mutant Forms ◽  
Dna Maintenance ◽  
Replication Intermediates ◽  
Chromatin Bridges

ABSTRACT Dna2 is a highly conserved helicase/nuclease that in yeast participates in Okazaki fragment processing, DNA repair, and telomere maintenance. Here, we investigated the biological function of human Dna2 (hDna2). Immunofluorescence and biochemical fractionation studies demonstrated that hDna2 was present in both the nucleus and the mitochondria. Analysis of mitochondrial hDna2 revealed that it colocalized with a subfraction of DNA-containing mitochondrial nucleoids in unperturbed cells. Upon the expression of disease-associated mutant forms of the mitochondrial Twinkle helicase which induce DNA replication pausing/stalling, hDna2 accumulated within nucleoids. RNA interference-mediated depletion of hDna2 led to a modest decrease in mitochondrial DNA replication intermediates and inefficient repair of damaged mitochondrial DNA. Importantly, hDna2 depletion also resulted in the appearance of aneuploid cells and the formation of internuclear chromatin bridges, indicating that nuclear hDna2 plays a role in genomic DNA stability. Together, our data indicate that hDna2 is similar to its yeast counterpart and is a new addition to the growing list of proteins that participate in both nuclear and mitochondrial DNA maintenance.

Discrimination between different groups of Candida parapsilosis by mitochondrial DNA restriction analysis

1988 ◽  
Vol 13 (5) ◽  
pp. 445-449 ◽  
Author(s):  
Nadine Camougrand ◽  
Bernard Mila ◽  
Gis�le Velours ◽  
Jaga Lazowska ◽  
Martine Gu�rin
Keyword(s):  
Mitochondrial Dna ◽  
Candida Parapsilosis ◽  
Restriction Analysis ◽  
Dna Restriction

scholarly journals Low doses of ultraviolet radiation and oxidative damage induce dramatic accumulation of mitochondrial DNA replication intermediates, fork regression, and replication initiation shift

2015 ◽  
Vol 26 (23) ◽  
pp. 4197-4208 ◽  
Author(s):  
Rubén Torregrosa-Muñumer ◽  
Steffi Goffart ◽  
Juha A. Haikonen ◽  
Jaakko L. O. Pohjoismäki
Keyword(s):  
Oxidative Stress ◽  
Mitochondrial Dna ◽  
Replication Initiation ◽  
Mtdna Copy Number ◽  
Strand Breaks ◽  
Rna:Dna Hybrid ◽  
Fork Regression ◽  
Cruciform Dna ◽  
Replication Intermediates ◽  
Massive Accumulation

Mitochondrial DNA is prone to damage by various intrinsic as well as environmental stressors. DNA damage can in turn cause problems for replication, resulting in replication stalling and double-strand breaks, which are suspected to be the leading cause of pathological mtDNA rearrangements. In this study, we exposed cells to subtle levels of oxidative stress or UV radiation and followed their effects on mtDNA maintenance. Although the damage did not influence mtDNA copy number, we detected a massive accumulation of RNA:DNA hybrid–containing replication intermediates, followed by an increase in cruciform DNA molecules, as well as in bidirectional replication initiation outside of the main replication origin, OH. Our results suggest that mitochondria maintain two different types of replication as an adaptation to different cellular environments; the RNA:DNA hybrid–involving replication mode maintains mtDNA integrity in tissues with low oxidative stress, and the potentially more error tolerant conventional strand-coupled replication operates when stress is high.

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