High impact information on QCR8

• To this end, the overlapping binding sites for ABF1 and CPF1 were mutated and placed in the chromosomal context of the QCR8 promoter [1].
• Global regulation of mitochondrial biogenesis in Saccharomyces cerevisiae: ABF1 and CPF1 play opposite roles in regulating expression of the QCR8 gene, which encodes subunit VIII of the mitochondrial ubiquinol-cytochrome c oxidoreductase [1].
• In Saccharomyces cerevisiae transcription of QCR8, encoding subunit VIII of the mitochondrial ubiquinol cytochrome c oxidoreductase, is subject to glucose repression, whereas in the distantly related yeast Kluyveromyces lactis it is not [2].
• In contrast, the octapeptide seems to have functional importance: the defect in the yeast qcr8-null mutant is not complemented on transformation with the construct encoding mature subunit VII from N. crassa in a single-copy plasmid [3].
• In Saccharomyces cerevisiae, the trans-membrane helix of Qcr8p, the ubiquinone binding protein of complex III, contributes to the Q binding site [4].

Biological context of QCR8

• Transcription was analyzed both under steady-state conditions and during nutritional shifts, in hap delta mutants and after site-specific mutagenesis of the various binding sites in the chromosomal context of the QCR8 gene [5].
• Regulation of mitochondrial biogenesis in Saccharomyces cerevisiae. Intricate interplay between general and specific transcription factors in the promoter of the QCR8 gene [5].
• Transformation of multi- and single-copy plasmids carrying a mutated version (LTN2, region 66-YWYWW-70 replaced by SASAA) of QCR8, the gene encoding the 11-kDa subunit ubiquinol-cytochrome c oxidoreductase of Saccharomyces cerevisiae, to a QCR8(0) strain indicated the importance of this aromatic region for the assembly of a functional enzyme [6].
• The QCR8 genes encoding subunit VIII of the bc1 complex from Kluyveromyces lactis and Schizosaccharomyces pombe partially complement the respiratory-deficient phenotype of a S. cerevisiae QCR8-null mutant [7].
• The chromatin structure at QCR8 during steady-state growth is, however, mainly dependent on binding of ABF1 to the promoter region [8].

Anatomical context of QCR8

• This implies that the heterologous Qcr8 subunits can be imported by S. cerevisiae mitochondria and that they assemble to form a hybrid bc1 complex that is sufficiently active to support growth [7].

Associations of QCR8 with chemical compounds

• Isolation and characterisation of the linked genes, FPS1 and QCR8, coding for farnesyl-diphosphate synthase and the 11 kDa subunit VIII of the mitochondrial bc1-complex in the yeast Kluyveromyces lactis [9].

Physical interactions of QCR8

• The N-terminus of the Qcr7 protein of the cytochrome bc(1) complex in S. cerevisiae may be involved in facilitating stability of the subcomplex with the Qcr8 protein and cytochrome b [10].

Other interactions of QCR8

• Previous studies have shown that the N-terminus of the Qcr7 protein may be involved in the assembly of the cytochrome bc(1) complex and its C-terminus by interacting with cytochrome b and QCR8 proteins [11].
• As in S. cerevisiae, chromosomal linkage between the K. lactis QCR8 and FPS1 genes is conserved, the two genes being separated by only 292 bp [9].
• We have investigated the involvement of ABF1 and CPF1 in chromatin organization at the QCR8 gene, encoding subunit VIII of the mitochondrial ubiquinol-cytochrome c oxidoreductase [8].

References