Identification of the gene encoding the human mitochondrial RNA polymerase (h-mtRPOL) by cyberscreening of the Expressed Sequence Tags database

Tiranti, Valeria; Savoia, Anna; Forti, Francesca; D’Apolito, Maria; Centra, Michele; Rocchi, Mariano; Zeviani, Massimo

doi:10.1093/hmg/6.4.615

Cited by 184 publications

(99 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The mitochondrial transcription machinery is highly simplified, consisting of only a single-subunit RNA polymerase (mtRPOL) and two transcription factors (15,16). The simplicity of this system suggests that coadaptation of mtRPOL and the mitochondrial promoter may evolve within isolated lineages.…”

Section: Discussionmentioning

confidence: 99%

“…Although only two transcription factors, TFAM and either TFB1M or TFB2M, are generally involved in mitochondrial transcription (15,16), a number of accessory proteins also appear to be involved in mitochondrial regulatory processes (33,34). Crosses involving the SD population repeatedly revealed poor function of SD-derived mtRPOL.…”

Section: Discussionmentioning

confidence: 99%

“…The mitochondrial genome is transcribed by a dedicated, nuclear-encoded RNA polymerase (mtRPOL), which functions independently of the transcription network of nuclear-encoded OXPHOS genes. In contrast to the large, multimeric nuclear RNA polymerase complexes, mtRPOL is a simple, phage-derived polymerase consisting of a singlesubunit core polymerase, mitochondrial transcription factor A (TFAM), and one of two mitochondrial transcription factor B paralogues (TFB1M and TFB2M) (15,16). Importantly, mtRPOL, and not one of the transcription factors, appears to be responsible for promoter binding affinity and specificity (17,18).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Genotype-dependent variation of mitochondrial transcriptional profiles in interpopulation hybrids

Ellison

Burton

2008

Proc. Natl. Acad. Sci. U.S.A.

120

View full text Add to dashboard Cite

Hybridization between populations can disrupt gene expression, frequently resulting in deleterious hybrid phenotypes. Reduced fitness in interpopulation hybrids of the marine copepod Tigriopus californicus has been traced to interactions between the nuclear and mitochondrial genomes. Here, we determine transcript levels of four to six genes involved in the mitochondrial oxidative phosphorylation pathway for a series of parental and inbred hybrid lines using RT-qPCR. Both nuclear and mitochondrial-encoded genes are included in the analysis. Although all genes studied are up-regulated under salinity stress, only expression of genes located on the mtDNA differed among lines. Because mitochondrial genes are transcribed by a dedicated RNA polymerase encoded in the nuclear genome, we compare transcript levels among hybrid lines with different combinations of mitochondrial RNA polymerase and mtDNA genotypes. Lines bearing certain mtDNA-mitochondrial RNA polymerase genotypic combinations show a diminished capacity to up-regulate mitochondrial genes in response to hypoosmotic stress. Effects on the transcriptional profile depend on the specific interpopulation cross and are correlated with viability effects. We hypothesize that disruption of the mitochondrial transcriptional system in F2 hybrids may play a central role in hybrid breakdown.hybrid breakdown ͉ mitochondria ͉ Tigriopus californicus ͉ transcription

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Genotype-dependent variation of mitochondrial transcriptional profiles in interpopulation hybrids

Ellison

Burton

2008

Proc. Natl. Acad. Sci. U.S.A.

120

View full text Add to dashboard Cite

show abstract

“…The comprehensively studied T7 RNAP can recognize specific promoter sequences, correctly initiate transcription, and catalyze transcript elongation until termination unaided by auxiliary proteins (reviewed in Cheetham and Steitz, 2000). In mitochondria of the budding yeast Saccharomyces cerevisiae (Greenleaf et al, 1986;Masters et al, 1987), mammals (Tiranti et al, 1997;Falkenberg et al, 2002;Gaspari et al, 2004), and other eukaryotic organisms (Cermakian et al, 1996), a nuclear-encoded T7 phage-type RNAP has replaced the ancestral bacterial-type RNAP. Transcription initiation in the mitochondria of yeast and mammals, however, depends on the transcriptional cofactor mtTFB (MTF1, TFBM), which is related to rRNA dimethyladenosine transferases (Winkley et al, 1985;Schinkel et al, 1987;Falkenberg et al, 2002;McCulloch et al, 2002;Matsunaga and Jaehning, 2004b).…”

Section: Introductionmentioning

confidence: 99%

Arabidopsis Phage-Type RNA Polymerases: Accurate in Vitro Transcription of Organellar Genes

Kühn¹,

Bohne²,

Liere

et al. 2007

The Plant Cell

View full text Add to dashboard Cite

The T7 bacteriophage RNA polymerase (RNAP) performs all steps of transcription, including promoter recognition, initiation, and elongation as a single-polypeptide enzyme. Arabidopsis thaliana possesses three nuclear-encoded T7 phage-type RNAPs that localize to mitochondria (RpoTm), plastids (RpoTp), or presumably both organelles (RpoTmp). Their specific functions are as yet unresolved. We have established an in vitro transcription system to examine the abilities of the three Arabidopsis phage-type RNAPs to synthesize RNA and to recognize organellar promoters. All three RpoT genes were shown to encode transcriptionally active RNAPs. RpoTmp displayed no significant promoter specificity, whereas RpoTm and RpoTp were able to accurately initiate transcription from overlapping subsets of mitochondrial and plastidial promoters without the aid of protein cofactors. Our study strongly suggests RpoTm to be the enzyme that transcribes most, if not all, mitochondrial genes in Arabidopsis. Intrinsic promoter specificity, a feature that RpoTm and RpoTp share with the T7 RNAP, appears to have been conserved over the long period of evolution of nuclear-encoded mitochondrial and plastidial RNAPs. Selective promoter recognition by the Arabidopsis phage-type RNAPs in vitro implies that auxiliary factors are required for efficient initiation of transcription in vivo.

show abstract

“…The human mitochondrial RNA polymerase (POLRMT) is a single-subunit enzyme related to the T7 family of bacteriophage RNA polymerases (9,10). However, unlike T7 RNA polymerase, which does not require any transcription factors, efficient promoter-specific initiation by human POLRMT in vitro requires the high mobility group box transcription factor h-mtTFA/TFAM (referred to as h-mtTFA from this point forward) and one of two rRNA methyltransferase-related transcription factors, h-mtTFB1 and h-mtTFB2 (11)(12)(13)(14).…”

mentioning

confidence: 99%

Core human mitochondrial transcription apparatus is a regulated two-component system in vitro

Shutt

Lodeiro

Cotney

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

118

View full text Add to dashboard Cite

The core human mitochondrial transcription apparatus is currently regarded as an obligate three-component system comprising the bacteriophage T7-related mitochondrial RNA polymerase, the rRNA methyltransferase-related transcription factor, h-mtTFB2, and the high mobility group box transcription/DNA-packaging factor, h-mtTFA/TFAM. Using a faithful recombinant human mitochondrial transcription system from Escherichia coli, we demonstrate that specific initiation from the mtDNA promoters, LSP and HSP1, only requires mitochondrial RNA polymerase and h-mtTFB2 in vitro. When h-mtTFA is added to these basal components, LSP exhibits a much lower threshold for activation and a larger amplitude response than HSP1. In addition, when LSP and HSP1 are together on the same transcription template, h-mtTFA-independent transcription from HSP1 and h-mtTFA-dependent transcription from both promoters is enhanced and a higher concentration of h-mtTFA is required to stimulate HSP1. Promoter competition experiments revealed that, in addition to LSP competing transcription components away from HSP1, additional cis-acting signals are involved in these aspects of promoter regulation. Based on these results, we speculate that the human mitochondrial transcription system may have evolved to differentially regulate transcription initiation and transcription-primed mtDNA replication in response to the amount of h-mtTFA associated with nucleoids, which could begin to explain the heterogeneity of nucleoid structure and activity in vivo. Furthermore, this study sheds new light on the evolution of mitochondrial transcription components by showing that the human system is a regulated two-component system in vitro, and thus more akin to that of budding yeast than thought previously.h-mtTFA/TFAM | mtDNA | nucleoid | POLRMT | h-mtTFB2/TFB2M

show abstract

Identification of the gene encoding the human mitochondrial RNA polymerase (h-mtRPOL) by cyberscreening of the Expressed Sequence Tags database

Cited by 184 publications

References 30 publications

Genotype-dependent variation of mitochondrial transcriptional profiles in interpopulation hybrids

Genotype-dependent variation of mitochondrial transcriptional profiles in interpopulation hybrids

Arabidopsis Phage-Type RNA Polymerases: Accurate in Vitro Transcription of Organellar Genes

Core human mitochondrial transcription apparatus is a regulated two-component system in vitro

Contact Info

Product

Resources

About