Control of mRNA turnover as a mechanism of glucose repression in Saccharomyces cerevisiae

We have examined the expression of the gene encoding the iron-protein subunit (Ip) of succinate dehydrogenase in Saccharomyces cerevisiae. The gene had been cloned by us and shown to be subject to glucose regulation (A. Lombardo, K. Carine, and I. E. Scheffler, J. Biol. Chem. 265:10419-10423, 1990). We discovered that a significant part of the regulation of the Ip mRNA levels by glucose involves the regulation of the turnover rate of this mRNA. In the presence of glucose, the half-life appears to be less than 5 min, while in glycerol medium, the half-life is greater than 60 min. The gene is also regulated transcriptionally by glucose. The upstream promoter sequence appeared to have four regulatory elements with consensus sequences shown to be responsible for the interaction with the HAP2/3/4 regulatory complex. A deletion analysis has shown that the two distal elements are redundant. These measurements were carried out by Northern (RNA) analyses of Ip mRNA transcripts as well as by assays of beta-galactosidase activity in cells carrying constructs of the Ip promoter linked to the lacZ coding sequence. These observations on the regulation of mRNA stability were also extended to the mRNA of the flavoprotein subunit of succinate dehydrogenase and in some experiments of iso-1-cytochrome c.

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Glucose-dependent turnover of the mRNAs encoding succinate dehydrogenase peptides in Saccharomyces cerevisiae: sequence elements in the 5' untranslated region of the Ip mRNA play a dominant role.

Molecular Biology of the Cell ◽

10.1091/mbc.6.9.1125 ◽

1995 ◽

Vol 6 (9) ◽

pp. 1125-1143 ◽

Cited By ~ 49

Author(s):

G P Cereghino ◽

D P Atencio ◽

M Saghbini ◽

J Beiner ◽

I E Scheffler

Keyword(s):

Saccharomyces Cerevisiae ◽

Carbon Source ◽

Succinate Dehydrogenase ◽

Half Life ◽

Untranslated Region ◽

Glucose Repression ◽

Dominant Role ◽

Initiation Factor ◽

Initiation Of Translation ◽

Nonfermentable Carbon Source

We have demonstrated previously that glucose repression of mitochondrial biogenesis in Saccharomyces cerevisiae involves the control of the turnover of mRNAs for the iron protein (Ip) and flavoprotein (Fp) subunits of succinate dehydrogenase (SDH). Their half-lives are > 60 min in the presence of a nonfermentable carbon source (YPG medium) and < 5 min in glucose (YPD medium). This is a rare example in yeast in which the half-lives are > 60 min in the presence of a nonfermentable carbon source (YPG medium) and < 5 min in glucose (YPD medium). This is a rare example in yeast in which the half-life of an mRNA can be controlled by manipulating external conditions. In our current studies, a series of Ip transcripts with internal deletions as well as chimeric transcripts with heterologous sequences (internally or at the ends) have been examined, and we established that the 5'-untranslated region (5' UTR) of the Ip mRNA contains a major determinant controlling its differential turnover in YPG and YPD. Furthermore, the 5' exonuclease encoded by the XRN1 gene is required for the rapid degradation of the Ip and Fp mRNAs upon the addition of glucose. In the presence of cycloheximide the nucleolytic degradation of the Ip mRNA can be slowed down by stalled ribosomes to allow the identification of intermediates. Such intermediates have lost their 5' ends but still retain their 3' UTRs. If protein synthesis is inhibited at an early initiation step by the use of a prt1 mutation (affecting the initiation factor eIF3), the Ip and Fp mRNAs are very rapidly degraded even in YPG. Significantly, the arrest of translation by the introduction of a stable hairpin loop just upstream of the initiation codon does not alter the differential stability of the transcript in YPG and YPD. These observations suggest that a signaling pathway exists in which the external carbon source can control the turnover of mRNAs of specific mitochondrial proteins. Factors must be present that control either the activity or more likely the access of a nuclease to the select mRNAs. As a result, we propose that a competition between initiation of translation and nuclease action at the 5' end of the transcript determines the half-life of the Ip mRNA.

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Arabidopsis thaliana Myb59 Gene Is Involved in the Response to Heterodera schachtii Infestation, and Its Overexpression Disturbs Regular Development of Nematode-Induced Syncytia

International Journal of Molecular Sciences ◽

10.3390/ijms22126450 ◽

2021 ◽

Vol 22 (12) ◽

pp. 6450

Author(s):

Anita Wiśniewska ◽

Kamila Wojszko ◽

Elżbieta Różańska ◽

Klaudia Lenarczyk ◽

Karol Kuczerski ◽

...

Keyword(s):

Cell Metabolism ◽

Gene Promoter ◽

Promoter Sequence ◽

Regulatory Elements ◽

Heterodera Schachtii ◽

Myb Transcription Factor ◽

Parasitic Nematodes ◽

Regulatory Sequences ◽

Gene Encoding ◽

Constitutive Overexpression

Transcription factors are proteins that directly bind to regulatory sequences of genes to modulate and adjust plants’ responses to different stimuli including biotic and abiotic stresses. Sedentary plant parasitic nematodes, such as beet cyst nematode, Heterodera schachtii, have developed molecular tools to reprogram plant cell metabolism via the sophisticated manipulation of genes expression, to allow root invasion and the induction of a sequence of structural and physiological changes in plant tissues, leading to the formation of permanent feeding sites composed of modified plant cells (commonly called a syncytium). Here, we report on the AtMYB59 gene encoding putative MYB transcription factor that is downregulated in syncytia, as confirmed by RT-PCR and a promoter pMyb59::GUS activity assays. The constitutive overexpression of AtMYB59 led to the reduction in A. thaliana susceptibility, as indicated by decreased numbers of developed females, and to the disturbed development of nematode-induced syncytia. In contrast, mutant lines with a silenced expression of AtMYB59 were more susceptible to this parasite. The involvement of ABA in the modulation of AtMYB59 gene transcription appears feasible by several ABA-responsive cis regulatory elements, which were identified in silico in the gene promoter sequence, and experimental assays showed the induction of AtMYB59 transcription after ABA treatment. Based on these results, we suggest that AtMYB59 plays an important role in the successful parasitism of H. schachtii on A. thaliana roots.

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Multiple regulatory elements control expression of the gene encoding the Saccharomyces cerevisiae cytochrome P450, lanosterol 14 alpha-demethylase (ERG11).

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)46051-6 ◽

1992 ◽

Vol 267 (3) ◽

pp. 2046-2056

Author(s):

T G Turi ◽

J C Loper

Keyword(s):

Saccharomyces Cerevisiae ◽

Cytochrome P450 ◽

Regulatory Elements ◽

Gene Encoding

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Rgt1, a glucose sensing transcription factor, is required for transcriptional repression of the HXK2 gene in Saccharomyces cerevisiae

Biochemical Journal ◽

10.1042/bj20050160 ◽

2005 ◽

Vol 388 (2) ◽

pp. 697-703 ◽

Cited By ~ 24

Author(s):

Aaron PALOMINO ◽

Pilar HERRERO ◽

Fernando MORENO

Keyword(s):

Saccharomyces Cerevisiae ◽

Transcription Factor ◽

Transcriptional Repression ◽

Glucose Repression ◽

Fold Increase ◽

Glucose Sensing ◽

Start Codon ◽

Dependent Manner ◽

Gene Encoding ◽

Regulatory Functions

Expression of HXK2, a gene encoding a Saccharomyces cerevisiae bifunctional protein with catalytic and regulatory functions, is controlled by glucose availability, being activated in the presence of glucose and inhibited when the levels of the sugar are low. In the present study, we identified Rgt1 as a transcription factor that, together with the Med8 protein, is essential for repression of the HXK2 gene in the absence of glucose. Rgt1 represses HXK2 expression by binding specifically to the motif (CGGAAAA) located at −395 bp relative to the ATG translation start codon in the HXK2 promoter. Disruption of the RGT1 gene causes an 18-fold increase in the level of HXK2 transcript in the absence of glucose. Rgt1 binds to the RGT1 element of HXK2 promoter in a glucose-dependent manner, and the repression of target gene depends on binding of Rgt1 to DNA. The physiological significance of the connection between two glucose-signalling pathways, the Snf3/Rgt2 that causes glucose induction and the Mig1/Hxk2 that causes glucose repression, was also analysed.

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Characterization of TUP1, a mediator of glucose repression in Saccharomyces cerevisiae.

Molecular and Cellular Biology ◽

10.1128/mcb.10.12.6500 ◽

1990 ◽

Vol 10 (12) ◽

pp. 6500-6511 ◽

Cited By ~ 106

Author(s):

F E Williams ◽

R J Trumbly

Keyword(s):

Saccharomyces Cerevisiae ◽

Insertional Mutagenesis ◽

Glucose Repression ◽

Coding Region ◽

Gene Encoding ◽

Reading Frame ◽

C Terminus ◽

Single Deletion ◽

Rna Mapping ◽

Mutant Phenotypes

The TUP1 and CYC8 (= SSN6) genes of Saccharomyces cerevisiae play a major role in glucose repression. Mutations in either TUP1 or CYC8 eliminate or reduce glucose repression of many repressible genes and induce other phenotypes, including flocculence, failure to sporulate, and sterility of MAT alpha cells. The TUP1 gene was isolated in a screen for genes that regulate mating type (V.L. MacKay, Methods Enzymol. 101:325-343, 1983). We found that a 3.5-kb restriction fragment was sufficient for complete complementation of tup1-100. The gene was further localized by insertional mutagenesis and RNA mapping. Sequence analysis of 2.9 kb of DNA including TUP1 revealed only one long open reading frame which predicts a protein of molecular weight 78,221. The predicted protein is rich in serine, threonine, and glutamine. In the carboxyl region there are six repeats of a pattern of about 43 amino acids. This same pattern of conserved residues is seen in the beta subunit of transducin and the yeast CDC4 gene product. Insertion and deletion mutants are viable, with the same range of phenotypes as for point mutants. Deletions of the 3' end of the coding region produced the same mutant phenotypes as did total deletions, suggesting that the C terminus is critical for TUP1 function. Strains with deletions in both the CYC8 and TUP1 genes are viable, with phenotypes similar to those of strains with a single deletion. A deletion mutation of TUP1 was able to suppress the snf1 mutation block on expression of the SUC2 gene encoding invertase.

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Characterization of the gene encoding the iron-sulfur protein subunit of succinate dehydrogenase from Drosophila melanogaster

Gene ◽

10.1016/0378-1119(94)90158-9 ◽

1994 ◽

Vol 149 (2) ◽

pp. 261-265 ◽

Cited By ~ 12

Author(s):

Harry C. Au ◽

Immo E. Scheffler

Keyword(s):

Drosophila Melanogaster ◽

Succinate Dehydrogenase ◽

Protein Subunit ◽

Gene Encoding ◽

Iron Sulfur ◽

Sulfur Protein ◽

Iron Sulfur Protein

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Gal80 proteins of Kluyveromyces lactis and Saccharomyces cerevisiae are highly conserved but contribute differently to glucose repression of the galactose regulon

Molecular and Cellular Biology ◽

10.1128/mcb.13.12.7566-7576.1993 ◽

1993 ◽

Vol 13 (12) ◽

pp. 7566-7576

Author(s):

F T Zenke ◽

W Zachariae ◽

A Lunkes ◽

K D Breunig

Keyword(s):

Saccharomyces Cerevisiae ◽

Binding Sites ◽

Glucose Repression ◽

Kluyveromyces Lactis ◽

Constitutive Expression ◽

Indirect Evidence ◽

Transcriptional Activator ◽

Negative Regulator ◽

Gene Encoding ◽

Fold Induction

We cloned the GAL80 gene encoding the negative regulator of the transcriptional activator Gal4 (Lac9) from the yeast Kluyveromyces lactis. The deduced amino acid sequence of K. lactis GAL80 revealed a strong structural conservation between K. lactis Gal80 and the homologous Saccharomyces cerevisiae protein, with an overall identity of 60% and two conserved blocks with over 80% identical residues. K. lactis gal80 disruption mutants show constitutive expression of the lactose/galactose metabolic genes, confirming that K. lactis Gal80 functions in essentially in the same way as does S. cerevisiae Gal80, blocking activation by the transcriptional activator Lac9 (K. lactis Gal4) in the absence of an inducing sugar. However, in contrast to S. cerevisiae, in which Gal4-dependent activation is strongly inhibited by glucose even in a gal80 mutant, glucose repressibility is almost completely lost in gal80 mutants of K. lactis. Indirect evidence suggests that this difference in phenotype is due to a higher activator concentration in K. lactis which is able to overcome glucose repression. Expression of the K. lactis GAL80 gene is controlled by Lac9. Two high-affinity binding sites in the GAL80 promoter mediate a 70-fold induction by galactose and hence negative autoregulation by Gal80. Gal80 in turn not only controls Lac9 activity but also has a moderate influence on its rate of synthesis. Thus, a feedback control mechanism exists between the positive and negative regulators. By mutating the Lac9 binding sites of the GAL80 promoter, we could show that induction of GAL80 is required to prevent activation of the lactose/galactose regulon in glycerol or glucose plus galactose, whereas the noninduced level of Gal80 is sufficient to completely block Lac9 function in glucose.

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