scholarly journals The MSN1 and NHP6A Genes Suppress SWI6 Defects in Saccharomyces cerevisiae

Genetics ◽  
1999 ◽  
Vol 151 (1) ◽  
pp. 45-55
Author(s):  
Julia Sidorova ◽  
Linda Breeden
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcription Factor ◽  
Transcription Factors ◽  
Dna Binding ◽  
Gene Transcription ◽  
Chromatin Structure ◽  
Transcriptional Activator ◽  
Temperature Sensitive ◽  
Gene Products ◽  
Protein Association

Abstract Ankyrin (ANK) repeats were first found in the Swi6 transcription factor of Saccharomyces cerevisiae and since then were identified in many proteins of eukaryotes and prokaryotes. These repeats are thought to serve as protein association domains. In Swi6, ANK repeats affect DNA binding of both the Swi4/Swi6 and Mbp1/Swi6 complexes. We have previously described generation of random mutations within the ANK repeats of Swi6 that render the protein temperature sensitive in its ability to activate HO transcription. Two of these SWI6 mutants were used in a screen for high copy suppressors of this phenotype. We found that MSN1, which encodes a transcriptional activator, and NHP6A, which encodes an HMG-like protein, are able to suppress defective Swi6 function. Both of these gene products are involved in HO transcription, and Nhp6A may also be involved in CLN1 transcription. Moreover, because overexpression of NHP6A can suppress caffeine sensitivity of one of the SWI6 ANK mutants, swi6-405, other SWI6-dependent genes may also be affected by Nhp6A. We hypothesize that Nhp6A and Msn1 modulate Swi6-dependent gene transcription indirectly, through effects on chromatin structure or other transcription factors, because we have not been able to demonstrate that either Msn1 or Nhp6A interact with the Swi4/Swi6 complex.

scholarly journals Mutational Analysis of AREA, a Transcriptional Activator Mediating Nitrogen Metabolite Repression in Aspergillus nidulans and a Member of the “Streetwise” GATA Family of Transcription Factors

1998 ◽  
Vol 62 (3) ◽  
pp. 586-596 ◽  
Author(s):  
Richard A. Wilson ◽  
Herbert N. Arst
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Dna Binding ◽  
Aspergillus Nidulans ◽  
Transcriptional Activator ◽  
Structural Genes ◽  
Gata Factor ◽  
Mutational Change ◽  
Nitrogen Metabolite Repression ◽  
Gata Family

SUMMARY The transcriptional activator AREA is a member of the GATA family of transcription factors and mediates nitrogen metabolite repression in the fungus Aspergillus nidulans. The nutritional versatility of A. nidulans and its amenability to classical and reverse genetic manipulations make the AREA DNA binding domain (DBD) a useful model for analyzing GATA family DBDs, particularly as structures of two AREA-DNA complexes have been determined. The 109 extant mutant forms of the AREA DBD surveyed here constitute one of the highest totals of eukaryotic transcription factor DBD mutants, are discussed in light of the roles of individual residues, and are compared to corresponding mutant sequence changes in other fungal GATA factor DBDs. Other topics include delineation of the DBD using both homology and mutational truncation, use of frameshift reversion to detect regions of tolerance to mutational change, the finding that duplication of the DBD can apparently enhance AREA function, and use of the AREA system to analyze a vertebrate GATA factor DBD. Some major points to emerge from work on the AREA DBD are (i) tolerance to sequence change (with retention of function) is surprisingly great, (ii) mutational changes in a transcription factor can have widely differing, even opposing, effects on expression of different structural genes so that monitoring expression of one or even several structural genes can be insufficient and possibly misleading, and (iii) a mutational change altering local hydrophobic packing and DNA binding target specificity can markedly influence the behavior of mutational changes elsewhere in the DBD.

scholarly journals Histone gene transcription factor binding in extracts of normal human cells.

1991 ◽  
Vol 11 (12) ◽  
pp. 5825-5831 ◽  
Author(s):  
F La Bella ◽  
N Heintz
Keyword(s):  
Cell Cycle ◽  
Transcription Factor ◽  
Transcription Factors ◽  
Dna Binding ◽  
Gene Transcription ◽  
Binding Activity ◽  
Histone Gene ◽  
Dna Binding Activity ◽  
Normal Human ◽  
Histone Gene Transcription

Transcriptional regulation of mammalian histone genes during S phase is achieved through activation of specific factors which interact with subtype-specific histone gene promoter sequences. It has previously been shown that in HeLa cells this induction is not mediated by obligatory changes in the DNA binding activity of histone gene transcription factors as cells progress through the cell cycle. Recently, it has been reported that the DNA binding properties of a putative histone gene transcription factor may be quite different in normal and transformed cells (J. Holthuis, T. A. Owen, A. J. van Wijnen, K. L. Wright, A. Ramsey-Ewing, M. B. Kennedy, R. Carter, S. C. Cosenza, K. J. Soprano, J. B. Lian, J. L. Stein, and G. S. Stein, Science 247:1454-1457, 1990). To determine whether the properties of well-characterized histone gene transcription factors are altered in transformed versus normal cells, we have examined the DNA binding activity of human histone transcription factors during the WI38 (a primary line of normal human fetal lung fibroblasts) cell cycle. The results demonstrate that the properties of Oct1, H4TF1, and H4TF2 are similar in WI38 and HeLa cells and that their DNA binding activities are constitutive during interphase of both normal and transformed cell lines. Although it remains possible that these factors are directly or indirectly perturbed as a result of cellular transformation, it appears unlikely that transformation results in gross changes in DNA binding activity as cells progress toward division.

Histone gene transcription factor binding in extracts of normal human cells

1991 ◽  
Vol 11 (12) ◽  
pp. 5825-5831
Author(s):  
F La Bella ◽  
N Heintz
Keyword(s):  
Cell Cycle ◽  
Transcription Factor ◽  
Transcription Factors ◽  
Dna Binding ◽  
Gene Transcription ◽  
Binding Activity ◽  
Histone Gene ◽  
Dna Binding Activity ◽  
Normal Human ◽  
Histone Gene Transcription

Transcriptional regulation of mammalian histone genes during S phase is achieved through activation of specific factors which interact with subtype-specific histone gene promoter sequences. It has previously been shown that in HeLa cells this induction is not mediated by obligatory changes in the DNA binding activity of histone gene transcription factors as cells progress through the cell cycle. Recently, it has been reported that the DNA binding properties of a putative histone gene transcription factor may be quite different in normal and transformed cells (J. Holthuis, T. A. Owen, A. J. van Wijnen, K. L. Wright, A. Ramsey-Ewing, M. B. Kennedy, R. Carter, S. C. Cosenza, K. J. Soprano, J. B. Lian, J. L. Stein, and G. S. Stein, Science 247:1454-1457, 1990). To determine whether the properties of well-characterized histone gene transcription factors are altered in transformed versus normal cells, we have examined the DNA binding activity of human histone transcription factors during the WI38 (a primary line of normal human fetal lung fibroblasts) cell cycle. The results demonstrate that the properties of Oct1, H4TF1, and H4TF2 are similar in WI38 and HeLa cells and that their DNA binding activities are constitutive during interphase of both normal and transformed cell lines. Although it remains possible that these factors are directly or indirectly perturbed as a result of cellular transformation, it appears unlikely that transformation results in gross changes in DNA binding activity as cells progress toward division.

scholarly journals Dispersed Mutations in Histone H3 That Affect Transcriptional Repression and Chromatin Structure of the CHA1 Promoter in Saccharomyces cerevisiae

2008 ◽  
Vol 7 (10) ◽  
pp. 1649-1660 ◽  
Author(s):  
Qiye He ◽  
Cailin Yu ◽  
Randall H. Morse
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chromatin Structure ◽  
Transcriptional Repression ◽  
Histone H3 ◽  
Temperature Sensitive ◽  
Active Chromatin ◽  
Temperature Sensitive Mutants ◽  
Nucleosome Structure ◽  
Lysine Residues ◽  
Chromatin Configuration

ABSTRACT The histone H3 amino terminus, but not that of H4, is required to prevent the constitutively bound activator Cha4 from remodeling chromatin and activating transcription at the CHA1 gene in Saccharomyces cerevisiae. Here we show that neither the modifiable lysine residues nor any specific region of the H3 tail is required for repression of CHA1. We then screened for histone H3 mutations that cause derepression of the uninduced CHA1 promoter and identified six mutants, three of which are also temperature-sensitive mutants and four of which exhibit a sin − phenotype. Histone mutant levels were similar to that of wild-type H3, and the mutations did not cause gross alterations in nucleosome structure. One specific and strongly derepressing mutation, H3 A111G, was examined in depth and found to cause a constitutively active chromatin configuration at the uninduced CHA1 promoter as well as at the ADH2 promoter. Transcriptional derepression and altered chromatin structure of the CHA1 promoter depend on the activator Cha4. These results indicate that modest perturbations in distinct regions of the nucleosome can substantially affect the repressive function of chromatin, allowing activation in the absence of a normal inducing signal (at CHA1) or of Swi/Snf (resulting in a sin − phenotype).

Dimeric transcription factor families: it takes two to tango but who decides on partners and the venue?

1992 ◽  
Vol 103 (1) ◽  
pp. 9-14 ◽  
Author(s):  
K.A. Lee
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Dna Binding ◽  
Experimental Evidence ◽  
Cdna Cloning ◽  
Transcriptional Activation ◽  
Effector Functions ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
Dna Elements

Dimeric transcription factors that bind to DNA are often grouped into families on the basis of dimerization and DNA-binding specificities. cDNA cloning studies have established that members of the same family have structurally related dimerisation and DNA-binding domains but diverge in other regions that are important for transcriptional activation. These features lead to the straightforward suggestion that although all members of a family bind to similar DNA elements, individual members exhibit distinct transcriptional effector functions. This simple view is now supported by experimental evidence from those systems that have proved amenable to study. There are however some largely unaddressed questions that concern the mechanisms that allow family members to go about their business without interference from their highly related siblings. Here I will discuss some insights from studies of the bZIP class of transcription factors.

scholarly journals The PAX3-FKHR fusion protein created by the t(2;13) translocation in alveolar rhabdomyosarcomas is a more potent transcriptional activator than PAX3.

1995 ◽  
Vol 15 (3) ◽  
pp. 1522-1535 ◽  
Author(s):  
W J Fredericks ◽  
N Galili ◽  
S Mukhopadhyay ◽  
G Rovera ◽  
J Bennicelli ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Dna Binding ◽  
Fusion Protein ◽  
Target Genes ◽  
Transcriptional Activator ◽  
Wild Type ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
Pediatric Solid Tumors ◽  
Single Polypeptide

Alveolar rhabdomyosarcomas are pediatric solid tumors with a hallmark cytogenetic abnormality: translocation of chromosomes 2 and 13 [t(2;13) (q35;q14)]. The genes on each chromosome involved in this translocation have been identified as the transcription factor-encoding genes PAX3 and FKHR. The NH2-terminal paired box and homeodomain DNA-binding domains of PAX3 are fused in frame to COOH-terminal regions of the chromosome 13-derived FKHR gene, a novel member of the forkhead DNA-binding domain family. To determine the role of the fusion protein in transcriptional regulation and oncogenesis, we identified the PAX3-FKHR fusion protein and characterized its function(s) as a transcription factor relative to wild-type PAX3. Antisera specific to PAX3 and FKHR were developed and used to examine PAX3 and PAX3-FKHR expression in tumor cell lines. Sequential immunoprecipitations with anti-PAX3 and anti-FKHR sera demonstrated expression of a 97-kDa PAX3-FKHR fusion protein in the t(2;13)-positive rhabdomyosarcoma Rh30 cell line and verified that a single polypeptide contains epitopes derived from each protein. The PAX3-FKHR protein was localized to the nucleus in Rh30 cells, as was wild-type PAX3, in t(2;13)-negative A673 cells. In gel shift assays using a canonical PAX binding site (e5 sequence), we found that DNA binding of PAX3-FKHR was significantly impaired relative to that of PAX3 despite the two proteins having identical PAX DNA-binding domains. However, the PAX3-FKHR fusion protein was a much more potent transcriptional activator than PAX3 as determined by transient cotransfection assays using e5-CAT reporter plasmids. The PAX3-FKHR protein may function as an oncogenic transcription factor by enhanced activation of normal PAX3 target genes.

scholarly journals Regulation of Transcription by Hypoxia Requires a Multiprotein Complex That Includes Hypoxia-Inducible Factor 1, an Adjacent Transcription Factor, and p300/CREB Binding Protein

1998 ◽  
Vol 18 (7) ◽  
pp. 4089-4096 ◽  
Author(s):  
Benjamin L. Ebert ◽  
H. Franklin Bunn
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Dna Binding ◽  
Binding Proteins ◽  
Binding Protein ◽  
Hypoxia Inducible Factor ◽  
Dna Binding Proteins ◽  
Creb Binding Protein ◽  
Multiprotein Complex ◽  
Hypoxia Inducible Factor 1

ABSTRACT Molecular adaptation to hypoxia depends on the binding of hypoxia-inducible factor 1 (HIF-1) to cognate response elements in oxygen-regulated genes. In addition, adjacent sequences are required for hypoxia-inducible transcription. To investigate the mechanism of interaction between these cis-acting sequences, the multiprotein complex binding to the lactate dehydrogenase A (LDH-A) promoter was characterized. The involvement of HIF-1, CREB-1/ATF-1, and p300/CREB binding protein (CBP) was demonstrated by techniques documenting in vitro binding, in combination with transient transfections that test the in vivo functional importance of each protein. In both the LDH-A promoter and the erythropoietin 3′ enhancer, formation of multiprotein complexes was analyzed by using biotinylated probes encompassing functionally critical cis-acting sequences. Strong binding of p300/CBP required interactions with multiple DNA binding proteins. Thus, the necessity of transcription factor binding sites adjacent to a HIF-1 site for hypoxically inducible transcription may be due to the requirement of p300 to interact with multiple transcription factors for high-affinity binding and activation of transcription. Since it has been found to interact with a wide range of transcription factors, p300 is likely to play a similar role in other genes, mediating interactions between DNA binding proteins, thereby activating stimulus-specific and tissue-specific gene transcription.

scholarly journals Identification of a DNA-binding site for the transcription factor Haa1, required for Saccharomyces cerevisiae response to acetic acid stress

2011 ◽  
Vol 39 (16) ◽  
pp. 6896-6907 ◽  
Author(s):  
Nuno P. Mira ◽  
Sílvia F. Henriques ◽  
Greg Keller ◽  
Miguel C. Teixeira ◽  
Rute G. Matos ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcription Factor ◽  
Acetic Acid ◽  
Dna Binding ◽  
Binding Site ◽  
Acid Stress ◽  
Dna Binding Site

scholarly journals A suppressor of an RNA polymerase II mutation of Saccharomyces cerevisiae encodes a subunit common to RNA polymerases I, II, and III.

1990 ◽  
Vol 10 (12) ◽  
pp. 6123-6131 ◽  
Author(s):  
J Archambault ◽  
K T Schappert ◽  
J D Friesen
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acid ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Essential Gene ◽  
Single Amino Acid ◽  
Temperature Sensitive ◽  
Gene Products ◽  
Gene Encoding ◽  
Temperature Sensitive Mutation

RNA polymerase II (RNAPII) is a complex multisubunit enzyme responsible for the synthesis of pre-mRNA in eucaryotes. The enzyme is made of two large subunits associated with at least eight smaller polypeptides, some of which are common to all three RNA polymerase species. We have initiated a genetic analysis of RNAPII by introducing mutations in RPO21, the gene encoding the largest subunit of RNAPII in Saccharomyces cerevisiae. We have used a yeast genomic library to isolate plasmids that can suppress a temperature-sensitive mutation in RPO21 (rpo21-4), with the goal of identifying gene products that interact with the largest subunit of RNAPII. We found that increased expression of wild-type RPO26, a single-copy, essential gene encoding a 155-amino-acid subunit common to RNAPI, RNAPII, and RNAPIII, suppressed the rpo21-4 temperature-sensitive mutation. Mutations were constructed in vitro that resulted in single amino acid changes in the carboxy-terminal portion of the RPO26 gene product. One temperature-sensitive mutation, as well as some mutations that did not by themselves generate a phenotype, were lethal in combination with rpo21-4. These results support the idea that the RPO26 and RPO21 gene products interact.

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