Disruption of the nuclear gene encoding the 20.8-kDa subunit of NADH:ubiquinone reductase of Neurospora mitochondria

1996 ◽  
Vol 252 (1-2) ◽  
pp. 177-183
Author(s):  
Margarida Vieira da Silva ◽  
Paulo Caseiro Alves *, † , Margarida ◽  
Alexandre Lobo-da-Cunha ◽  
Troy A. A. Harkness ◽  
Frank E. Nargang
Keyword(s):  
Nuclear Gene ◽  
Gene Encoding ◽  
Nadh:Ubiquinone Reductase

Disruption of the nuclear gene encoding the 20.8-kDa subunit of NADH:ubiquinone reductase ofNeurospora mitochondria

1996 ◽  
Vol 252 (1-2) ◽  
pp. 177-183 ◽  
Author(s):  
M. V. da Silva ◽  
P. C. Alves ◽  
M. Duarte ◽  
N. Mota ◽  
A. Lobo-da-Cunha ◽  
...  
Keyword(s):  
Nuclear Gene ◽  
Gene Encoding ◽  
Nadh:Ubiquinone Reductase

Overproduction of yeast viruslike particles by strains deficient in a mitochondrial nuclease

1989 ◽  
Vol 9 (8) ◽  
pp. 3323-3331
Author(s):  
Y X Liu ◽  
C L Dieckmann
Keyword(s):  
Coat Protein ◽  
Killer Toxin ◽  
Nuclear Gene ◽  
Fold Increase ◽  
Mitochondrial Outer Membrane ◽  
Gene Encoding ◽  
Recessive Mutations ◽  
A Genome ◽  
Nonfermentable Carbon Source ◽  
Viruslike Particles

Saccharomyces cerevisiae strains are often host to several types of cytoplasmic double-stranded RNA (dsRNA) genomes, some of which are encapsidated by the L-A dsRNA product, an 86,000-dalton coat protein. Here we present the finding that nuclear recessive mutations in the NUC1 gene, which encodes the major nonspecific nuclease of yeast mitochondria, resulted in at least a 10-fold increase in amounts of the L-A dsRNA and its encoded coat protein. The effect of nuc1 mutations on L-A abundance was completely suppressed in strains that also hosted the killer-toxin-encoding M dsRNA. Both NUC1 and nuc1 strains containing the L-A genome exhibited an increase in coat protein abundance and a concomitant increase in L-A dsRNA when the cells were grown on a nonfermentable carbon source rather than on glucose, an effect independent of the increase in coat protein due to nuc1 mutations or to the absence of M. The increase in L-A expression in nuc1 strains was similar to that observed in strains with mutations in the nuclear gene encoding the most abundant outer mitochondrial membrane protein, porin. nuc1 mutations did not affect the level of porin in the mitochondrial outer membrane. Since the effect of mutations in nuc1 was to alter the copy number of the L-A coat protein genome rather than to change the level of the M toxin genome (as do mak and ski mutations), these mutations define a new class of nuclear genes affecting yeast dsRNA abundance.

Saccharomyces cerevisiae contains two functional citrate synthase genes

1986 ◽  
Vol 6 (6) ◽  
pp. 1936-1942
Author(s):  
K S Kim ◽  
M S Rosenkrantz ◽  
L Guarente
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Citrate Synthase ◽  
Tricarboxylic Acid Cycle ◽  
Nuclear Gene ◽  
Tricarboxylic Acid ◽  
Yeast Genome ◽  
Gene Encoding ◽  
Acid Cycle ◽  
Nonfermentable Carbon Source

The tricarboxylic acid cycle occurs within the mitochondria of the yeast Saccharomyces cerevisiae. A nuclear gene encoding the tricarboxylic acid cycle enzyme citrate synthase has previously been isolated (M. Suissa, K. Suda, and G. Schatz, EMBO J. 3:1773-1781, 1984) and is referred to here as CIT1. We report here the isolation, by an immunological method, of a second nuclear gene encoding citrate synthase (CIT2). Disruption of both genes in the yeast genome was necessary to produce classical citrate synthase-deficient phenotypes: glutamate auxotrophy and poor growth on rich medium containing lactate, a nonfermentable carbon source. Therefore, the citrate synthase produced from either gene was sufficient for these metabolic roles. Transcription of both genes was maximally repressed in medium containing both glucose and glutamate. However, transcription of CIT1 but not of CIT2 was derepressed in medium containing a nonfermentable carbon source. The significance of the presence of two genes encoding citrate synthase in S. cerevisiae is discussed.

scholarly journals Sequences required for delivery and localization of the ADP/ATP translocator to the mitochondrial inner membrane.

1986 ◽  
Vol 6 (2) ◽  
pp. 626-634 ◽  
Author(s):  
G S Adrian ◽  
M T McCammon ◽  
D L Montgomery ◽  
M G Douglas
Keyword(s):  
Transmembrane Protein ◽  
Nuclear Gene ◽  
Translocator Protein ◽  
Gene Encoding ◽  
Inner Membrane ◽  
Amino Terminal ◽  
Mitochondrial Inner Membrane ◽  
Membrane Anchoring ◽  
High Degree

The ADP/ATP translocator, a transmembrane protein of the mitochondrial inner membrane, is coded in Saccharomyces cerevisiae by the nuclear gene PET9. DNA sequence analysis of the PET9 gene showed that it encoded a protein of 309 amino acids which exhibited a high degree of homology with mitochondrial translocator proteins from other sources. This mitochondrial precursor, in contrast to many others, does not contain a transient presequence which has been shown to direct the posttranslational localization of proteins in the organelle. Gene fusions between the PET9 gene and the gene encoding beta-galactosidase (lacZ) were constructed to define the location of sequences necessary for the mitochondrial delivery of the ADP/ATP translocator protein in vivo. These studies reveal that the information to target the hybrid molecule to the mitochondria is present within the first 115 residues of the protein. In addition, these studies suggest that the "import information" of the amino-terminal region of the ADP/ATP translocator precursor is twofold. In addition to providing targeting function of the precursor to the organelle, these amino-terminal sequences act to prevent membrane-anchoring sequences located between residues 78 and 98 from stopping import at the outer mitochondrial membrane. These results are discussed in light of the function of distinct protein elements at the amino terminus of mitochondrially destined precursors in both organelle delivery and correct membrane localization.

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