Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P51532 (transcriptional activator)
 6,546 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The assembly of the respiratory apparatus requires the coordinate expression of a large number of genes from both nuclear and mitochondrial genetic systems. In vertebrate organisms, the molecular mechanisms integrating the activities of these distinct genomic compartments in response to tissue demands for respiratory energy remain unknown. A potential inroad to this problem came with the discovery of nuclear respiratory factor 1 (NRF-1), a novel transcriptional activator defined by mutational and DNA binding analysis of the somatic cytochrome c promoter. Functional NRF-1 sites are now observed in several other recently isolated nuclear genes whose products function in the mitochondria. Among these are genes encoding subunits of the cytochrome c oxidase (subunit VIc) and reductase (ubiquinone-binding protein) complexes. In addition, a functional NRF-1 site resides in the MRP RNA gene encoding the RNA moiety of a ribonucleoprotein endonuclease involved in mitochondrial DNA replication. Synthetic oligomers of these sites competitively displace NRF-1 binding to the cytochrome c promoter. NRF-1-binding activities for each site also have the same thermal lability, copurify chromatographically, and make similar guanosine nucleotide contacts within each recognition sequence. Moreover, NRF-1 recognition in vitro correlates with the ability of each site to stimulate expression in vivo from a truncated cytochrome c promoter. The presence of NRF-1-binding sites in nuclear genes encoding structural components of the mammalian electron transport chain, as well as the mitochondrial DNA replication machinery, suggests a mechanism for coordination of nuclear and mitochondrial genetic systems through the concerted modulation of nuclear genes.
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PMID:NRF-1: a trans-activator of nuclear-encoded respiratory genes in animal cells. 216 1

We report the isolation and characterization of the KlQCR7 gene encoding subunit VII of the mitochondrial bc1 complex of the yeast Kluyveromyces lactis. The coding region is 69.3% identical to its counterpart in Saccharomyces cerevisiae (ScQCR7). Like the KlQCR8 gene (Mulder et al., accompanying paper) expression of the KlQCR7 gene during growth on glucose is high and can be further induced when cells are grown on non-fermentable carbon sources. The chromosomal linkage of the APA2 and QCR7 genes is conserved between S. cerevisiae and K. lactis. The intergenic regions containing the QCR7 promoters of the two yeasts, differ significantly in length and lack overall DNA sequence similarity, but they do share a binding site for the transcription factor complex HAP2/3/4. The KlQCR7 promoter contains, in addition, a CPF1 consensus binding site which is absent from ScQCR7. Deletion of a 35 bp region containing these two sites severely lowers the mRNA expression during growth on both glucose and ethanol/glycerol, but growth rate on both carbon sources is only mildly affected. Interestingly, in respect to the KlQCR7 gene, KlCPF1 seems to act as an important transcriptional activator, thus contrasting the proposed repressor function of ScCPF1 for the ScQCR8 gene of S. cerevisiae.
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PMID:Isolation and characterisation of the linked genes APA2 and QCR7, coding for Ap4A phosphorylase II and the 14 kDa subunit VII of the mitochondrial bc1-complex in the yeast Kluyveromyces lactis. 794 33

HAP4 encodes a transcriptional activator of respiration-related genes and so, redirection from fermentation to respiration flux should give rise to an increase in biomass production in Saccharomyces cerevisiae transformants that overexpress HAP4. With this aim, three bakers' yeasts, that is, V1 used for lean doughs, its 2-deoxy-D-glucose resistant derivative DOG21, and V3 employed for sweet doughs, were transformed with integrative cassettes that carried HAP4 gene under the control of constitutive promoter pTEF2; in addition VTH, DTH and 3TH transformants were selected and characterized. Transformants showed increased expression of HAP4 and respiration-related genes such as QCR7 and QCR8 with regard to parental, and similar expression of SUC2 and MAL12; these genes are relevant in bakers' industry. Invertase (Suc2p) and maltase (Mal12p) activities, growth and sugar consumption rates in laboratory (YPD) or industrial media (MAB) were also comparable in bakers' strains and their transformants, but VTH, DTH and 3TH increased their final biomass production by 9.5, 5.0 and 5.0% respectively as compared to their parentals in MAB. Furthermore, V1 and its transformant VTH had comparable capacity to ferment lean doughs (volume increase rate and final volume) while V3 and its transformant 3TH fermented sweet doughs in a similar manner. Therefore transformants possessed increased biomass yield and appropriate characteristics to be employed in bakers' industry because they lacked drug resistant markers and bacterial DNA, and were genetically stable.
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PMID:Increased biomass production of industrial bakers' yeasts by overexpression of Hap4 gene. 2083 86