A DNA polymerization-independent role for mitochondrial DNA polymerase I-like protein C in African trypanosomes
Autor: | Jonathan C. Miller, Jeniffer Concepción-Acevedo, Michael J. Boucher, Stephanie B. Delzell, Michele M. Klingbeil |
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Rok vydání: | 2019 |
Předmět: |
DNA Replication
Mitochondrial DNA biology DNA polymerase DNA Kinetoplast Trypanosoma brucei brucei Protozoan Proteins Cell Biology Minicircle DNA Polymerase I DNA Mitochondrial Cell biology DNA Polymerase gamma Polymerization Kinetoplast parasitic diseases biology.protein DNA polymerase I Polymerase Mitochondrial nucleoid Mitochondrial DNA replication Protein C Research Article |
Zdroj: | J Cell Sci |
ISSN: | 1477-9137 |
Popis: | 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 a single nucleoid requires at least three DNA polymerase I-like proteins (i.e. POLIB, POLIC and POLID), each showing discrete localizations near the kDNA during S phase. POLIB and POLID have roles in minicircle replication but the specific role of POLIC in kDNA maintenance is less clear. Here, we use an RNA interference (RNAi)-complementation system to dissect the functions of two distinct POLIC regions, i.e. the conserved family A DNA polymerase (POLA) domain and the uncharacterized N-terminal region (UCR). While RNAi complementation with wild-type POLIC restored kDNA content and cell cycle localization of kDNA, active site point mutations in the POLA domain impaired minicircle replication similar to that of POLIB and POLID depletions. Complementation with POLA domain alone abolished the formation of POLIC foci and partially rescued the RNAi phenotype. Furthermore, we provide evidence that the UCR is crucial in cell cycle-dependent protein localization and facilitates proper distribution of progeny networks. This is the first report of a DNA polymerase that impacts on mitochondrial nucleoid distribution. This article has an associated First Person interview with the first author of the paper. |
Databáze: | OpenAIRE |
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