Mitochondrial Telomere-binding Protein from Candida parapsilosis Suggests an Evolutionary Adaptation of a Nonspecific Single-stranded DNA-binding Protein

Nosek, Jozef; Tomáška, Ľubomír; Pagác̆ová, Blanka; Fukuhara, Hiroshi

doi:10.1074/jbc.274.13.8850

Cited by 34 publications

(29 citation statements)

References 33 publications

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“…Moreover, it has been demonstrated that linear mtDNA retains its structural and functional integrity in the presence of ethidium bromide and acridine orange, a feature which may underlie the ability of C. parapsilosis to grow in the presence of high levels of these intercalating agents (Maleszka 1994). A series of analyses has confirmed the linear nature of this mitochondrial genome and uncovered specific terminal structures (mitochondrial telomeres) consisting of tandem arrays of a 738-bp unit and a 5¢ single-stranded protrusion of about 110 nt (Nosek et al 1995), which is protected by a protein cap (Nosek et al 1999;Tomaska et al 2001). Moreover, it has been demonstrated that mitochondrial telomeres adopt a higher-order structure (telomeric loop, t-loop; Tomaska et al 2002), like that found in the nuclear chromosomes of eukaryotes (Griffith et al 1999).…”

Section: Introductionmentioning

confidence: 82%

Complete DNA sequence of the linear mitochondrial genome of the pathogenic yeast Candida parapsilosis

et al. 2004

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The complete sequence of the mitochondrial DNA of the opportunistic yeast pathogen Candida parapsilosis was determined. The mitochondrial genome is represented by linear DNA molecules terminating with tandem repeats of a 738-bp unit. The number of repeats varies, thus generating a population of linear DNA molecules that are heterogeneous in size. The length of the shortest molecules is 30,922 bp, whereas the longer molecules have expanded terminal tandem arrays (nx738 bp). The mitochondrial genome is highly compact, with less than 8% of the sequence corresponding to non-coding intergenic spacers. In silico analysis predicted genes encoding fourteen protein subunits of complexes of the respiratory chain and ATP synthase, rRNAs of the large and small subunits of the mitochondrial ribosome, and twenty-four transfer RNAs. These genes are organized into two transcription units. In addition, six intronic ORFs coding for homologues of RNA maturase, reverse transcriptase and DNA endonucleases were identified. In contrast to its overall molecular architecture, the coding sequences of the linear mitochondrial DNA of C. parapsilosis are highly similar to their counterparts in the circular mitochondrial genome of its close relative C. albicans. The complete sequence has implications for both mitochondrial DNA replication and the evolution of linear DNA genomes.

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Section: Introductionmentioning

confidence: 82%

Complete DNA sequence of the linear mitochondrial genome of the pathogenic yeast Candida parapsilosis

et al. 2004

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“…This hypothesis is consistent with what has been observed for certain fungi (Tomá ka et al, 2001). In Candida species in which the mitochondrial genome has linearized, a divergent mtSSB now appears to function as a telomere binding protein (Nosek et al, 1995(Nosek et al, , 1998. With the apparent linear conformation of the plant mitochondrial genome, that could be the situation in plants as well.…”

Section: Discussionmentioning

confidence: 99%

Nuclear Genes That Encode Mitochondrial Proteins for DNA and RNA Metabolism Are Clustered in the Arabidopsis Genome[W]

et al. 2003

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The plant mitochondrial genome is complex in structure, owing to a high degree of recombination activity that subdivides the genome and increases genetic variation. The replication activity of various portions of the mitochondrial genome appears to be nonuniform, providing the plant with an ability to modulate its mitochondrial genotype during development. These and other interesting features of the plant mitochondrial genome suggest that adaptive changes have occurred in DNA maintenance and transmission that will provide insight into unique aspects of plant mitochondrial biology and mitochondrial-chloroplast coevolution. A search in the Arabidopsis genome for genes involved in the regulation of mitochondrial DNA metabolism revealed a region of chromosome III that is unusually rich in genes for mitochondrial DNA and RNA maintenance. An apparently similar genetic linkage was observed in the rice genome. Several of the genes identified within the chromosome III interval appear to target the plastid or to be targeted dually to the mitochondria and the plastid, suggesting that the process of endosymbiosis likely is accompanied by an intimate coevolution of these two organelles for their genome maintenance functions.

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“…As mitochondrial telomeres seem to fulfill analogous biological functions and display all the essential features of their nuclear counterparts, i.e. they consist of arrays of tandem repeats and possess a protruding single-stranded overhang (16) that is capped by specific telomere-binding protein (33,34) and telomeric loops (27), mitochondria harboring linear mitochondrial genomes may represent a molecular fossil (35) of the original telomere replication strategy (36). Telomeric loops seem to represent a general, evolutionary conserved property of terminal tandem arrays and may explain several telomererelated phenomena such as capping function, masking the ends from DNA repair machinery providing a solution to the endreplication problem, and telomere rapid deletion (7,8).…”

Section: Resultsmentioning

confidence: 99%

Amplification of Telomeric Arrays via Rolling-circle Mechanism

Nosek¹,

Rycovska²,

Makhov

et al. 2005

Journal of Biological Chemistry

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Alternative (telomerase-independent) lengthening of telomeres mediated through homologous recombination is often accompanied by a generation of extrachromosomal telomeric circles (t-circles), whose role in direct promotion of recombinational telomere elongation has been recently demonstrated. Here we present evidence that t-circles in a natural telomerase-deficient system of mitochondria of the yeast Candida parapsilosis replicate independently of the linear chromosome via a rollingcircle mechanism. This is supported by an observation of (i) single-stranded DNA consisting of concatameric arrays of telomeric sequence, (ii) lasso-shaped molecules representing rolling-circle intermediates, and (iii) preferential incorporation of deoxyribonucleotides into telomeric fragments and t-circles. Analysis of naturally occurring variant t-circles revealed conserved motifs with potential function in driving the rolling-circle replication. These data indicate that extrachromosomal t-circles observed in a wide variety of organisms, including yeasts, plants, Xenopus laevis, and certain human cell lines, may represent independent replicons generating telomeric sequences and, thus, actively participating in telomere dynamics. Moreover, because of the promiscuous occurrence of t-circles across phyla, the results from yeast mitochondria have implications related to the primordial system of telomere maintenance, providing a paradigm for evolution of telomeres in nuclei of early eukaryotes.

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Mitochondrial Telomere-binding Protein from Candida parapsilosis Suggests an Evolutionary Adaptation of a Nonspecific Single-stranded DNA-binding Protein

Cited by 34 publications

References 33 publications

Complete DNA sequence of the linear mitochondrial genome of the pathogenic yeast Candida parapsilosis

Complete DNA sequence of the linear mitochondrial genome of the pathogenic yeast Candida parapsilosis

Nuclear Genes That Encode Mitochondrial Proteins for DNA and RNA Metabolism Are Clustered in the Arabidopsis Genome[W]

Amplification of Telomeric Arrays via Rolling-circle Mechanism

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