scholarly journals A DNA polymerization-independent role for mitochondrial DNA polymerase I-like protein C in African trypanosomes

2020 ◽  
Vol 133 (9) ◽  
pp. jcs233072 ◽  
Author(s):  
Jonathan C. Miller ◽  
Stephanie B. Delzell ◽  
Jeniffer Concepción-Acevedo ◽  
Michael J. Boucher ◽  
Michele M. Klingbeil
Keyword(s):  
Mitochondrial Dna ◽  
Dna Polymerase ◽  
Protein C ◽  
Dna Polymerase I ◽  
African Trypanosomes ◽  
Dna Polymerization ◽  
Polymerase I ◽  
Mitochondrial Dna Polymerase

scholarly journals Characterization of the mitochondrial DNA polymerase from Saccharomyces cerevisiae.

1994 ◽  
Vol 41 (1) ◽  
pp. 79-86 ◽  
Author(s):  
S Sen ◽  
S Mukhopadhyay ◽  
J Wetzel ◽  
T K Biswas
Keyword(s):  
Mitochondrial Dna ◽  
Dna Polymerase ◽  
Nuclear Dna ◽  
Dna Polymerase I ◽  
Specificity And Sensitivity ◽  
Protease Deficient ◽  
Polymerase I ◽  
Mitochondrial Dna Polymerase

The mitochondrial DNA (mtDNA) polymerase was isolated from a protease-deficient yeast strain (PY2), and purified about 3000 fold by a column chromatography on phosphocellulose, heparin-agarose, and single-stranded DNA cellulose. The purified polymerase was characterized with respect to optimal nucleotide concentrations, template-primer specificity and sensitivity to some inhibitors. These results were compared with the nuclear DNA polymerase I activity. Both polymerases showed similar requirement of deoxynucleotide concentrations (Km < 1 microM), and highest activity with poly(dA-dT) template. However, the mtDNA polymerase was more sensitive to ddTTP, EtBr and Mn2+ inhibition in comparison to the nuclear DNA polymerase I. The mtDNA polymerase did not need ATP as an energy source for in vitro DNA synthesis. This mtDNA polymerase preparation also showed 3'-->5' exonuclease activity.

scholarly journals Mitochondrial DNA polymerase POLIB is essential for minicircle DNA replication in African trypanosomes

2010 ◽  
Vol 75 (6) ◽  
pp. 1414-1425 ◽  
Author(s):  
David F. Bruhn ◽  
Brian Mozeleski ◽  
Laurie Falkin ◽  
Michele M. Klingbeil
Keyword(s):  
Mitochondrial Dna ◽  
Dna Replication ◽  
Dna Polymerase ◽  
African Trypanosomes ◽  
Mitochondrial Dna Polymerase ◽  
Minicircle Dna

scholarly journals Cell cycle localization dynamics of mitochondrial DNA polymerase IC in African trypanosomes

2018 ◽  
Vol 29 (21) ◽  
pp. 2540-2552 ◽  
Author(s):  
Jeniffer Concepción-Acevedo ◽  
Jonathan C. Miller ◽  
Michael J. Boucher ◽  
Michele M. Klingbeil
Keyword(s):  
Cell Cycle ◽  
Mitochondrial Dna ◽  
Dna Polymerase ◽  
Dna Polymerases ◽  
Dynamic Environment ◽  
African Trypanosomes ◽  
Protein Levels ◽  
Replication Sites ◽  
Cycle Dependent ◽  
Mitochondrial Dna Polymerase

Trypanosoma brucei has a unique catenated mitochondrial DNA (mtDNA) network called kinetoplast DNA (kDNA). Replication of kDNA occurs once per cell cycle in near synchrony with nuclear S phase and requires the coordination of many proteins. Among these are three essential DNA polymerases (TbPOLIB, IC, and ID). Localization dynamics of these proteins with respect to kDNA replication stages and how they coordinate their functions during replication are not well understood. We previously demonstrated that TbPOLID undergoes dynamic localization changes that are coupled to kDNA replication events. Here, we report the localization of TbPOLIC, a second essential DNA polymerase, and demonstrate the accumulation of TbPOLIC foci at active kDNA replication sites (antipodal sites) during stage II of the kDNA duplication cycle. While TbPOLIC was undetectable by immunofluorescence during other cell cycle stages, steady-state protein levels measured by Western blot remained constant. TbPOLIC foci colocalized with the fraction of TbPOLID that localized to the antipodal sites. However, the partial colocalization of the two essential DNA polymerases suggests a highly dynamic environment at the antipodal sites to coordinate the trafficking of replication proteins during kDNA synthesis. These data indicate that cell cycle–dependent localization is a major regulatory mechanism for essential mtDNA polymerases during kDNA replication.

scholarly journals Structure-function analysis reveals a DNA polymerization-independent role for mitochondrial DNA polymerase IC in African trypanosomes

2019 ◽  
Author(s):  
Jonathan C Miller ◽  
Stephanie B Delzell ◽  
Jeniffer Concepción-Acevedo ◽  
Michael J Boucher ◽  
Michele M Klingbeil
Keyword(s):  
Cell Cycle ◽  
Mitochondrial Dna ◽  
Dna Polymerase ◽  
Function Analysis ◽  
Point Mutations ◽  
Rnai Phenotype ◽  
African Trypanosomes ◽  
Dna Segregation ◽  
Summary Statement ◽  
Mitochondrial Dna Polymerase

ABSTRACTThe mitochondrial DNA of Trypanosoma brucei and related parasites is a catenated network containing thousands of minicircles and tens of maxicircles called kinetoplast DNA (kDNA). Replication of the single nucleoid requires at least three DNA polymerases (POLIB, POLIC, and POLID) each having discrete localization near the kDNA during S phase. POLIB and POLID have roles in minicircle replication while the specific role of POLIC in kDNA maintenance is less clear. Here, we use an RNAi-complementation system to dissect the functions of the distinct POLIC domains: the conserved family A DNA polymerase domain (POLA) and the uncharacterized N-terminal region (UCR). While RNAi complementation with wild-type POLIC restored kDNA content and cell cycle localization, active site point mutations in the POLA domain impaired minicircle replication similarly to POLIB and POLID depletions. Complementation with the POLA domain alone abolished POLIC foci formation and partially rescued the RNAi phenotype. Furthermore, we provide evidence of a crucial role for the UCR in cell cycle localization and segregation of kDNA daughter networks. This is the first report of a DNA polymerase that impacts DNA segregation.Summary statementMitochondrial DNA segregation in African trypanosomes is supported by a dual-functioning DNA polymerase.

scholarly journals Characteristics of DNA polymerase I from an extreme thermophile, Thermus scotoductus strain K1

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Ani Saghatelyan ◽  
Hovik Panosyan ◽  
Armen Trchounian ◽  
Nils‐Kåre Birkeland
Keyword(s):  
Dna Polymerase ◽  
Extreme Thermophile ◽  
Dna Polymerase I ◽  
Polymerase I
Sign in / Sign up

Export Citation Format

Share Document