Mutations causing high basal level transcription that is independent of transcriptional activators but dependent on chromosomal position in Saccharomyces cerevisiae

Harashima, Satoshi; Mizuno, Takayuki; Mabuchi, H.; Yoshimitsu, Shin-ichi; Ramesh, Ray; Hasebe, Masaharu; Tanaka, Atsuko; Oshima, Yasuji

doi:10.1007/bf00290403

Cited by 24 publications

(28 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Supporting this idea of cis effects from within lacZ, W. Hörz (personal communication) has shown that a sin4 mutation affects expression of a PHO5-lacZ reporter, but a sin4 mutation does not cause derepression of the native PHO5 gene. Additionally, the fact that a sin4 mutation derepresses PHO5 transplaced into the URA3 locus, but not the native PHO5 locus, suggests that effects of a sin4 mutation can be influenced by the chromosomal context (21). Finally, the concept of cis-acting effects of lacZ sequences affecting transcriptional regulation is supported by the work of Chávez and Aguilera (10) showing that an hpr1 mutation affects native genes and lacZ reporters differently.…”

Section: Discussionmentioning

confidence: 48%

Architectural Transcription Factors and the SAGA Complex Function in Parallel Pathways To Activate Transcription

Eriksson

Stillman

2000

Molecular and Cellular Biology

View full text Add to dashboard Cite

Recent work has shown that transcription of the yeast HO gene involves the sequential recruitment of a series of transcription factors. We have performed a functional analysis of HO regulation by determining the ability of mutations in SIN1, SIN3, RPD3, and SIN4 negative regulators to permit HO expression in the absence of certain activators. Mutations in the SIN1 (‫؍‬SPT2) gene do not affect HO regulation, in contrast to results of other studies using an HO:lacZ reporter, and our data show that the regulatory properties of an HO:lacZ reporter differ from that of the native HO gene. Mutations in SIN3 and RPD3, which encode components of a histone deacetylase complex, show the same pattern of genetic suppression, and this suppression pattern differs from that seen in a sin4 mutant. The Sin4 protein is present in two transcriptional regulatory complexes, the RNA polymerase II holoenzyme/mediator and the SAGA histone acetylase complex. Our genetic analysis allows us to conclude that Swi/Snf chromatin remodeling complex has multiple roles in HO activation, and the data suggest that the ability of the SBF transcription factor to bind to the HO promoter may be affected by the acetylation state of the HO promoter. We also demonstrate that the Nhp6 architectural transcription factor, encoded by the redundant NHP6A and NHP6B genes, is required for HO expression. Suppression analysis with sin3, rpd3, and sin4 mutations suggests that Nhp6 and Gcn5 have similar functions. A gcn5 nhp6a nhp6b triple mutant is extremely sick, suggesting that the SAGA complex and the Nhp6 architectural transcription factors function in parallel pathways to activate transcription. We find that disruption of SIN4 allows this strain to grow at a reasonable rate, indicating a critical role for Sin4 in detecting structural changes in chromatin mediated by Gcn5 and Nhp6. These studies underscore the critical role of chromatin structure in regulating HO gene expression.The Saccharomyces cerevisiae HO gene encodes an endonuclease that is responsible for initiating mating type switching in yeast. The transcriptional regulation of HO is complex and has been the subject of intensive study (for reviews, see references 22 and 37). Recent studies have shown that transcription of specific genes can be affected by chromatin structure at the promoter (for reviews, see references 25, 28, 54, and 59). Chromatin structure plays an important role in regulation of HO transcription, as HO expression is altered by mutations in a number of important transcriptional regulators, including components of the Swi/Snf chromatin remodeling complex, the SAGA histone acetyltransferase complex, and the Sin3/Rpd3 histone deacetylase complex. GCN5, ADA2, and ADA3, which encode members of the SAGA histone acetyltransferase complex (18), are required for HO:lacZ expression (43), and native HO expression is also reduced in a gcn5 mutant (41). The yeast RPD3 gene encodes a histone deacetylase that is associated with Sin3 (26, 27). SIN3 and RPD3 are negative regulators of transcription...

show abstract

Section: Discussionmentioning

confidence: 48%

Architectural Transcription Factors and the SAGA Complex Function in Parallel Pathways To Activate Transcription

Eriksson

Stillman

2000

Molecular and Cellular Biology

View full text Add to dashboard Cite

show abstract

“…We observed that the NUT1 and NUT2 genes are similarly required for the repression of pPHO5-lacZ but do not affect the repression of the endogenous PHO5 gene. Harashima et al have observed that SIN4 mutations allow constitutive transcription of the PHO5 gene when the PHO5 promoter and open reading frame are integrated at the URA3 locus (19).…”

Section: Discussionmentioning

confidence: 99%

“…Although we have yet to determine the identity of the remaining genes that function like NUT2, some may encode other proteins in the Ccr4p complex, and likewise Nut1p and Nut2p might physically interact with the Ccr4p complex. Remarkably, Harashima et al identified two different two-gene traits, one due to mutations in BEL3 and BEL7 and the other due to mutations in BEL5 and BEL6, that affect the repression of PHO5 at a heterologous genomic locus but not at its native locus (19). Not only is the nut1 nut2 mutant similarly defective in two genes, but it shares with these two bel mutants rough colony morphology, flocculent growth in liquid culture, and elevated expression of artificial, albeit different reporter genes.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Nuclear Proteins Nut1p and Nut2p Cooperate To Negatively Regulate a Swi4p-DependentlacZReporter Gene inSaccharomyces cerevisiae

Tabtiang

Herskowitz

1998

Molecular and Cellular Biology

View full text Add to dashboard Cite

The URS2 region of the Saccharomyces cerevisiae HO upstream region contains 10 binding sites for the Swi4p/Swi6p transcription factor and confers Swi4p dependence for transcription. Using a hybrid promoter, UAS GAL (upstream activation sequence of GAL1)-URS2R, in which the GAL1-10 regulatory region is fused to the proximal 360 bp of URS2, we isolated mutants in which Swi4p is no longer required for transcription. Mutations of SIN4, ROX3, SRB8, SRB9, SRB10, SRB11, and two novel genes, NUT1 and NUT2, relieve the requirement of Swi4p for expression of this reporter. We found that NUT1 (open reading frame [ORF] YGL151w) is a nonessential gene, that NUT2 (ORF YPR168w) is essential, and that both Nut1p and Nut2p encode nuclear proteins. Deletion of NUT1 causes a constitutive, Swi4p-independent phenotype only in combination with the nut2-1 allele or an allele of CCR4. In contrast, inactivation of a temperature-sensitive allele of NUT2, nut2-ts70, alone causes constitutivity. nut1⌬ nut2-1 cells and sin4⌬ cells exhibit Swi4p-independent expression of an ho-lacZ reporter but not of an intact ho gene. Likewise, a pPHO5-lacZ construct is constitutively expressed in nut1 nut2 mutants relative to their wild-type counterparts. These results suggest that Nut1p, Nut2p, Sin4p, and Ccr4p define a group of proteins that negatively regulate transcription in a subtle manner which is revealed by artificial reporter genes.

show abstract

“…The 6.2-kb HindlII-SphI fragment from YIp33 [15] was ligated with the 2.2-kb HindlII-SphI fragment from p714 [16] to give p813. The PCR product for MET25 promoter (MET25p) was doubly digested with HindlII and BamHI, and then inserted into the HindlIIBamHI gap of pSH39 [17] and p813 to construct p886 and p953, respectively.…”

Section: Recombinant Dnamentioning

confidence: 99%

Single point mutations in Met4p impair the transcriptional repression of MET genes in Saccharomyces cerevisiae

Omura¹,

Fujita²,

Shibano³

1996

FEBS Letters

View full text Add to dashboard Cite

Mutations causing high basal level transcription that is independent of transcriptional activators but dependent on chromosomal position in Saccharomyces cerevisiae

Cited by 24 publications

References 45 publications

Architectural Transcription Factors and the SAGA Complex Function in Parallel Pathways To Activate Transcription

Architectural Transcription Factors and the SAGA Complex Function in Parallel Pathways To Activate Transcription

Nuclear Proteins Nut1p and Nut2p Cooperate To Negatively Regulate a Swi4p-DependentlacZReporter Gene inSaccharomyces cerevisiae

Single point mutations in Met4p impair the transcriptional repression of MET genes in Saccharomyces cerevisiae

Contact Info

Product

Resources

About