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TFAM’s Contributions to mtDNA Replication and OXPHOS Biogenesis Are Genetically Separable

The ability of animal orthologs of human mitochondrial transcription factor A (hTFAM) to support the replication of human mitochondrial DNA (hmtDNA) does not follow a simple pattern of phylogenetic closeness or sequence similarity. In particular, TFAM from chickens (Gallus gallus, chTFAM), unlike TF...

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Autores principales: Kozhukhar, Natalya, Alexeyev, Mikhail F.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9739059/
https://www.ncbi.nlm.nih.gov/pubmed/36497015
http://dx.doi.org/10.3390/cells11233754
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author Kozhukhar, Natalya
Alexeyev, Mikhail F.
author_facet Kozhukhar, Natalya
Alexeyev, Mikhail F.
author_sort Kozhukhar, Natalya
collection PubMed
description The ability of animal orthologs of human mitochondrial transcription factor A (hTFAM) to support the replication of human mitochondrial DNA (hmtDNA) does not follow a simple pattern of phylogenetic closeness or sequence similarity. In particular, TFAM from chickens (Gallus gallus, chTFAM), unlike TFAM from the “living fossil” fish coelacanth (Latimeria chalumnae), cannot support hmtDNA replication. Here, we implemented the recently developed GeneSwap approach for reverse genetic analysis of chTFAM to obtain insights into this apparent contradiction. By implementing limited “humanization” of chTFAM focused either on amino acid residues that make DNA contacts, or the ones with significant variances in side chains, we isolated two variants, Ch13 and Ch22. The former has a low mtDNA copy number (mtCN) but robust respiration. The converse is true of Ch22. Ch13 and Ch22 complement each other’s deficiencies. Opposite directionalities of changes in mtCN and respiration were also observed in cells expressing frog TFAM. This led us to conclude that TFAM’s contributions to mtDNA replication and respiratory chain biogenesis are genetically separable. We also present evidence that TFAM residues that make DNA contacts play the leading role in mtDNA replication. Finally, we present evidence for a novel mode of regulation of the respiratory chain biogenesis by regulating the supply of rRNA subunits.
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spelling pubmed-97390592022-12-11 TFAM’s Contributions to mtDNA Replication and OXPHOS Biogenesis Are Genetically Separable Kozhukhar, Natalya Alexeyev, Mikhail F. Cells Article The ability of animal orthologs of human mitochondrial transcription factor A (hTFAM) to support the replication of human mitochondrial DNA (hmtDNA) does not follow a simple pattern of phylogenetic closeness or sequence similarity. In particular, TFAM from chickens (Gallus gallus, chTFAM), unlike TFAM from the “living fossil” fish coelacanth (Latimeria chalumnae), cannot support hmtDNA replication. Here, we implemented the recently developed GeneSwap approach for reverse genetic analysis of chTFAM to obtain insights into this apparent contradiction. By implementing limited “humanization” of chTFAM focused either on amino acid residues that make DNA contacts, or the ones with significant variances in side chains, we isolated two variants, Ch13 and Ch22. The former has a low mtDNA copy number (mtCN) but robust respiration. The converse is true of Ch22. Ch13 and Ch22 complement each other’s deficiencies. Opposite directionalities of changes in mtCN and respiration were also observed in cells expressing frog TFAM. This led us to conclude that TFAM’s contributions to mtDNA replication and respiratory chain biogenesis are genetically separable. We also present evidence that TFAM residues that make DNA contacts play the leading role in mtDNA replication. Finally, we present evidence for a novel mode of regulation of the respiratory chain biogenesis by regulating the supply of rRNA subunits. MDPI 2022-11-24 /pmc/articles/PMC9739059/ /pubmed/36497015 http://dx.doi.org/10.3390/cells11233754 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Kozhukhar, Natalya
Alexeyev, Mikhail F.
TFAM’s Contributions to mtDNA Replication and OXPHOS Biogenesis Are Genetically Separable
title TFAM’s Contributions to mtDNA Replication and OXPHOS Biogenesis Are Genetically Separable
title_full TFAM’s Contributions to mtDNA Replication and OXPHOS Biogenesis Are Genetically Separable
title_fullStr TFAM’s Contributions to mtDNA Replication and OXPHOS Biogenesis Are Genetically Separable
title_full_unstemmed TFAM’s Contributions to mtDNA Replication and OXPHOS Biogenesis Are Genetically Separable
title_short TFAM’s Contributions to mtDNA Replication and OXPHOS Biogenesis Are Genetically Separable
title_sort tfam’s contributions to mtdna replication and oxphos biogenesis are genetically separable
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9739059/
https://www.ncbi.nlm.nih.gov/pubmed/36497015
http://dx.doi.org/10.3390/cells11233754
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