scholarly journals Mitochondrial instability in a strain ofSaccharomyces cerevisiae

1978 ◽  
Vol 32 (2) ◽  
pp. 171-182 ◽  
Author(s):  
I. H. Evans ◽  
D. Wilkie
Keyword(s):  
Saccharomyces Cerevisiae ◽  
High Frequency ◽  
Glucose Repression ◽  
Point Mutations ◽  
Nuclear Gene ◽  
Fermentable Sugars ◽  
Glucose Medium ◽  
Haploid Strain ◽  
Respiratory Impairment ◽  
Mutator Effect

SUMMARYA haploid strain ofSaccharomyces cerevisiaehas been described which, on glucose medium, segregates vegetatively a high frequency of mutants with different degrees of respiratory impairment. The range of mutants seemingly encompasses both non-revertible ρ- petites and revertible point mutations resembling leakymit- mutations. The segregants have aberrant cytochrome contents and reduced growth capabilities on fermentable sugars other than glucose; these defects apparently correlate with the degree of respiratory impairment. Genetic analysis of this mutator phenomenon has implicated a nuclear gene which appears to show specificity of interaction with the mitochondrial genome as well as a requirement for glucose repression. The mutator effect seems to extend also to the loci in mitochondrial DNA for resistance to the antibiotics erythromycin and oligomycin.

scholarly journals Transcriptional Regulation of CLN3Expression by Glucose in Saccharomyces cerevisiae

1998 ◽  
Vol 180 (17) ◽  
pp. 4508-4515 ◽  
Author(s):  
Fereshteh Parviz ◽  
Duane D. Hall ◽  
David D. Markwardt ◽  
Warren Heideman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcriptional Activation ◽  
Mitotic Cycle ◽  
Specific Interaction ◽  
Point Mutations ◽  
Yeast Cells ◽  
Mrna Levels ◽  
Glucose Medium ◽  
Constant Size ◽  
Promoter Mutations

ABSTRACT In Saccharomyces cerevisiae, the transition from the G1 phase of the mitotic cycle into S phase is controlled by a set of G1 cyclins that regulate the activity of the protein kinase encoded by CDC28. Yeast cells regulate progress through the G1/S boundary in response to nutrients, moving quickly through G1 in glucose medium and more slowly in poorer medium. We have examined connections between glucose and the level of the message encoding Cln3, a G1cyclin. We found that glucose positively regulates CLN3mRNA levels through a set of repeated AAGAAAAA (A2GA5) elements within theCLN3 promoter. Mutations in these sequences reduce both transcriptional activation and specific interaction betweenCLN3 promoter elements and proteins in yeast extracts. Creation of five point mutations, replacing the G’s within these repeats with T’s, in the CLN3 promoter substantially reduces CLN3 expression in glucose medium and inhibits the ability of the cells to maintain a constant size when shifted into glucose.

The residual enzymatic phosphorylation activity of hexokinase II mutants is correlated with glucose repression in Saccharomyces cerevisiae

1989 ◽  
Vol 9 (12) ◽  
pp. 5643-5649
Author(s):  
H Ma ◽  
L M Bloom ◽  
C T Walsh ◽  
D Botstein
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Glucose Repression ◽  
Point Mutations ◽  
Inverse Correlation ◽  
Invertase Activity ◽  
Yeast Cells ◽  
Hexokinase Ii ◽  
Mutant Proteins ◽  
Hexokinase Activity

Saccharomyces cerevisiae mutants containing different point mutations in the HXK2 gene were used to study the relationship between phosphorylation by hexokinase II and glucose repression in yeast cells. Mutants showing different levels of hexokinase activity were examined for the degree of glucose repression as indicated by the levels of invertase activity. The levels of hexokinase activity and invertase activity showed a strong inverse correlation, with a few exceptions attributable to very unstable hexokinase II proteins. The in vivo hexokinase II activity was determined by measuring growth rates, using fructose as a carbon source. This in vivo hexokinase II activity was similarly inversely correlated with invertase activity. Several hxk2 alleles were transferred to multicopy plasmids to study the effects of increasing the amounts of mutant proteins. The cells that contained the multicopy plasmids exhibited less invertase and more hexokinase activity, further strengthening the correlation. These results strongly support the hypothesis that the phosphorylation activity of hexokinase II is correlated with glucose repression.

Inactivation of YME1, a member of the ftsH-SEC18-PAS1-CDC48 family of putative ATPase-encoding genes, causes increased escape of DNA from mitochondria in Saccharomyces cerevisiae

1993 ◽  
Vol 13 (9) ◽  
pp. 5418-5426 ◽  
Author(s):  
P E Thorsness ◽  
K H White ◽  
T D Fox
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Cell Division ◽  
Synthetic Lethality ◽  
Nuclear Gene ◽  
Growth Defect ◽  
Glucose Medium ◽  
Cold Sensitive ◽  
Encoding Genes ◽  
Six Genes

The yeast nuclear gene YME1 was one of six genes recently identified in a screen for mutations that elevate the rate at which DNA escapes from mitochondria and migrates to the nucleus. yme1 mutations, including a deletion, cause four known recessive phenotypes: an elevation in the rate at which copies of TRP1 and ARS1, integrated into the mitochondrial genome, escape to the nucleus; a heat-sensitive respiratory-growth defect; a cold-sensitive growth defect on rich glucose medium; and synthetic lethality in rho- (cytoplasmic petite) cells. The cloned YME1 gene complements all of these phenotypes. The gene product, Yme1p, is immunologically detectable as an 82-kDa protein present in mitochondria. Yme1p is a member of a family of homologous putative ATPases, including Sec18p, Pas1p, Cdc48p, TBP-1, and the FtsH protein. Yme1p is most similar to the Escherichia coli FtsH protein, an essential protein involved in septum formation during cell division. This observation suggests the hypothesis that Yme1p may play a role in mitochondrial fusion and/or division.

Identification of an upstream activation sequence and other cis-acting elements required for transcription of COX6 from Saccharomyces cerevisiae

1989 ◽  
Vol 9 (12) ◽  
pp. 5350-5358
Author(s):  
J D Trawick ◽  
C Rogness ◽  
R O Poyton
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fusion Gene ◽  
Glucose Repression ◽  
Nuclear Gene ◽  
Orientation Dependence ◽  
Tata Box ◽  
Translational Initiation ◽  
Cis Acting ◽  
Deletion Mutagenesis ◽  
Activation Sequence

Transcription of Saccharomyces cerevisiae COX6, the nuclear gene for subunit VI of cytochrome c oxidase, is activated in heme-proficient cells, requires the HAP2 gene, and is subject to glucose repression. In this study, by deletion mutagenesis of the COX6 promoter, we identified two regions that are important for transcription. The first was an upstream activation site, UAS6. It was found to be contained within an 84-base-pair (bp) sequence, between bp -256 and -340 of the COX6 translational initiation codon, and to contain sequences required for activation by heme and HAP2 and for release from glucose repression. When located upstream of a CYC1-lacZ fusion gene, deleted for both of its UASs, this segment functioned as a UAS element. Although UAS6 could promote expression in either orientation, it showed a marked orientation dependence in its response to HAP2 and the carbon source. The second region lay between bp -255 and -91. It contained two of the three major 5' termini of COX6 mRNAs and a putative TATA box. Deletion analysis of this region demonstrated that the putative TATA box is not required for transcription and that this region is separable into two redundant domains.

scholarly journals The residual enzymatic phosphorylation activity of hexokinase II mutants is correlated with glucose repression in Saccharomyces cerevisiae.

1989 ◽  
Vol 9 (12) ◽  
pp. 5643-5649 ◽  
Author(s):  
H Ma ◽  
L M Bloom ◽  
C T Walsh ◽  
D Botstein
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Glucose Repression ◽  
Point Mutations ◽  
Inverse Correlation ◽  
Invertase Activity ◽  
Yeast Cells ◽  
Hexokinase Ii ◽  
Mutant Proteins ◽  
Hexokinase Activity

Saccharomyces cerevisiae mutants containing different point mutations in the HXK2 gene were used to study the relationship between phosphorylation by hexokinase II and glucose repression in yeast cells. Mutants showing different levels of hexokinase activity were examined for the degree of glucose repression as indicated by the levels of invertase activity. The levels of hexokinase activity and invertase activity showed a strong inverse correlation, with a few exceptions attributable to very unstable hexokinase II proteins. The in vivo hexokinase II activity was determined by measuring growth rates, using fructose as a carbon source. This in vivo hexokinase II activity was similarly inversely correlated with invertase activity. Several hxk2 alleles were transferred to multicopy plasmids to study the effects of increasing the amounts of mutant proteins. The cells that contained the multicopy plasmids exhibited less invertase and more hexokinase activity, further strengthening the correlation. These results strongly support the hypothesis that the phosphorylation activity of hexokinase II is correlated with glucose repression.

scholarly journals Adjacent upstream activation sequence elements synergistically regulate transcription of ADH2 in Saccharomyces cerevisiae.

1989 ◽  
Vol 9 (1) ◽  
pp. 34-42 ◽  
Author(s):  
J Yu ◽  
M S Donoviel ◽  
E T Young
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Glucose Repression ◽  
Point Mutations ◽  
Single Copy ◽  
Upstream Activation Sequence ◽  
Sequence Elements ◽  
Adh2 Promoter ◽  
Activation Sequence

A 22-base-pair (bp) inverted repeat present in the ADH2 promoter is an upstream activation sequence (UAS1) which confers ADR1-dependent activation upon a heterologous Saccharomyces cerevisiae promoter. UAS1 was nonfunctional when placed within an intron 3' to the transcription start site. The 11-bp sequence which constitutes one-half of the UAS1 palindrome did not activate transcription in a single copy, as direct repeats, or in an inverted orientation opposite to that of ADH2 UAS1. Furthermore, two pairs of symmetrical point mutations within UAS1 significantly reduced activation. This result suggests that a specific orientation of sequences within UAS1 is necessary for ADR1-dependent activation. We determined that an ADR1-dependent complex was formed with UAS1 and, to a lesser extent, with the nonfunctional 11-bp half palindrome. However, the 11 bp did not confer UAS activity, suggesting that ADR1 binding is not sufficient for activation in vivo. ADR1 did not bind to mutant UAS1 sequences in vitro, indicating that their decreased activation is attributable to a reduced affinity of ADR1 for these sequences. We also identified an additional 20-bp ADH2 element (UAS2) that increased the expression of CYC1-lacZ 20-fold when combined with UAS1. UAS2 permitted ADR1-independent, glucose-regulated expression of the hybrid gene. Consistent with this observation, ADR1 did not form a detectable complex with UAS2. Deletion of UAS2 at the chromosomal ADH2 locus virtually abolished ADH2 derepression and had no effect on glucose repression.

scholarly journals Inactivation of YME1, a member of the ftsH-SEC18-PAS1-CDC48 family of putative ATPase-encoding genes, causes increased escape of DNA from mitochondria in Saccharomyces cerevisiae.

1993 ◽  
Vol 13 (9) ◽  
pp. 5418-5426 ◽  
Author(s):  
P E Thorsness ◽  
K H White ◽  
T D Fox
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Cell Division ◽  
Synthetic Lethality ◽  
Nuclear Gene ◽  
Growth Defect ◽  
Glucose Medium ◽  
Cold Sensitive ◽  
Encoding Genes ◽  
Six Genes

The yeast nuclear gene YME1 was one of six genes recently identified in a screen for mutations that elevate the rate at which DNA escapes from mitochondria and migrates to the nucleus. yme1 mutations, including a deletion, cause four known recessive phenotypes: an elevation in the rate at which copies of TRP1 and ARS1, integrated into the mitochondrial genome, escape to the nucleus; a heat-sensitive respiratory-growth defect; a cold-sensitive growth defect on rich glucose medium; and synthetic lethality in rho- (cytoplasmic petite) cells. The cloned YME1 gene complements all of these phenotypes. The gene product, Yme1p, is immunologically detectable as an 82-kDa protein present in mitochondria. Yme1p is a member of a family of homologous putative ATPases, including Sec18p, Pas1p, Cdc48p, TBP-1, and the FtsH protein. Yme1p is most similar to the Escherichia coli FtsH protein, an essential protein involved in septum formation during cell division. This observation suggests the hypothesis that Yme1p may play a role in mitochondrial fusion and/or division.

scholarly journals Suppressors of ‘blue’ mutations in yeast

1974 ◽  
Vol 23 (1) ◽  
pp. 37-45 ◽  
Author(s):  
I. de G. Mitchell ◽  
E. A. Bevan
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Methylene Blue ◽  
Temperature Sensitivity ◽  
High Frequency ◽  
Agar Medium ◽  
Nuclear Gene ◽  
Nutrient Agar ◽  
Wild Type ◽  
Cytoplasmic Factor ◽  
Nutrient Agar Medium

SummaryMutants ofSaccharomyces cerevisiaewhose colonies were blue when grown on nutrient agar medium containing methylene blue reverted to wild-type with white-colony phenotype at high frequency. This reversion was controlled by nuclear gene suppressors in some mutants, and by cytoplasmic suppressors in others. Each of the latter suppressed several independetly segregating blue mutants. These suppressors could be divided into two classes: suppression by petite mutations which behaved as recessives, and suppression by a cytoplasmic factor in respiration-sufficient cells which behaved as dominant over wild-type but might also be a mutation ofrho. A relationship between blue mutation and temperature sensitivity was suggested.

scholarly journals GENE CONVERSION AND INTRAGENIC RECOMBINATION AT AT THE SUP6 LOCUS AND THE SURROUNDING REGION IN SACCHAROMYCES CEREVISIAE

Genetics ◽  
1976 ◽  
Vol 84 (4) ◽  
pp. 697-721
Author(s):  
Laura Dicaprio ◽  
P J Hastings
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Conversion ◽  
High Frequency ◽  
High Conversion ◽  
Intragenic Recombination ◽  
Maximum Frequency ◽  
Haploid Strain ◽  
Meiotic Gene ◽  
Conversion Frequency

ABSTRACT Spontaneous secondary mutations of the ochre suppressor SUP6 were selected in a haploid strain of Saccharomyces cerevisiae. Unselected tetrads were dissected from crosses heterozygous for one of three alleles of SUP6 and for three other loci in this region which span a length of 14 map units (his2, cdc14 and met10). The study showed that all of these markers were characterized by high frequency of meiotic gene conversion and long conversion lengths which frequently extended into adjacent marked loci. Despite the high conversion frequency of SUP6, recombination between alleles of this locus reached a maximum frequency of only 2 × 10-3 prototrophs/spore. Although the allelic recombination frequencies were not distance dependent and consequently could not be used to order the alleles, the inequality between the two recombinant outside marker combinations among selected intragenic recombinants produced an internally consistent map of the suppressor locus. Recombination at SUP6 (whether detected as conversion in tetrads or the production of recombinants among random spores) was accompanied by significantly less than 50% outside marker recombination.

Adjacent upstream activation sequence elements synergistically regulate transcription of ADH2 in Saccharomyces cerevisiae

1989 ◽  
Vol 9 (1) ◽  
pp. 34-42
Author(s):  
J Yu ◽  
M S Donoviel ◽  
E T Young
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Glucose Repression ◽  
Point Mutations ◽  
Single Copy ◽  
Upstream Activation Sequence ◽  
Sequence Elements ◽  
Adh2 Promoter ◽  
Activation Sequence

A 22-base-pair (bp) inverted repeat present in the ADH2 promoter is an upstream activation sequence (UAS1) which confers ADR1-dependent activation upon a heterologous Saccharomyces cerevisiae promoter. UAS1 was nonfunctional when placed within an intron 3' to the transcription start site. The 11-bp sequence which constitutes one-half of the UAS1 palindrome did not activate transcription in a single copy, as direct repeats, or in an inverted orientation opposite to that of ADH2 UAS1. Furthermore, two pairs of symmetrical point mutations within UAS1 significantly reduced activation. This result suggests that a specific orientation of sequences within UAS1 is necessary for ADR1-dependent activation. We determined that an ADR1-dependent complex was formed with UAS1 and, to a lesser extent, with the nonfunctional 11-bp half palindrome. However, the 11 bp did not confer UAS activity, suggesting that ADR1 binding is not sufficient for activation in vivo. ADR1 did not bind to mutant UAS1 sequences in vitro, indicating that their decreased activation is attributable to a reduced affinity of ADR1 for these sequences. We also identified an additional 20-bp ADH2 element (UAS2) that increased the expression of CYC1-lacZ 20-fold when combined with UAS1. UAS2 permitted ADR1-independent, glucose-regulated expression of the hybrid gene. Consistent with this observation, ADR1 did not form a detectable complex with UAS2. Deletion of UAS2 at the chromosomal ADH2 locus virtually abolished ADH2 derepression and had no effect on glucose repression.

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