scholarly journals Combinatorial Repression of the Hypoxic Genes of Saccharomyces cerevisiae by DNA Binding Proteins Rox1 and Mot3

2005 ◽  
Vol 4 (4) ◽  
pp. 649-660 ◽  
Author(s):  
Lee G. Klinkenberg ◽  
Thomas A. Mennella ◽  
Katharina Luetkenhaus ◽  
Richard S. Zitomer
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Binding ◽  
Chromatin Immunoprecipitation ◽  
Binding Sites ◽  
Binding Protein ◽  
Dna Binding Protein ◽  
Aerobic Growth ◽  
Repression Complex ◽  
Combinatorial Interactions

ABSTRACT The hypoxic genes of Saccharomyces cerevisiae are transcriptionally repressed during aerobic growth through recruitment of the Ssn6/Tup1 general repression complex by the DNA binding protein Rox1. A second DNA binding protein Mot3 enhances repression of some hypoxic genes. Previous studies characterized the role of Mot3 at the hypoxic ANB1 gene as promoting synergy among one Mot3 site and two Rox1 sites comprising operator A of that gene. Here we studied the role of Mot3 in enhancing repression by Rox1 at another hypoxic gene, HEM13, which is less strongly regulated than ANB1 and has a very different arrangement of Rox1 and Mot3 binding sites. By assessing the effects of deleting Rox1 and Mot3 sites individually and in combination, we found that the major repression of HEM13 occurred through three Mot3 sites closely spaced with a single Rox1 site. While the Mot3 sites functioned additively, they enhanced repression by the single Rox1 site, and the presence of Rox1 enhanced the additive effects of the Mot3 sites. In addition, using a Rox1-Ssn6 fusion protein, we demonstrated that Mot3 enhances Rox1 repression through helping recruit the Ssn6/Tup1 complex. Chromatin immunoprecipitation assays indicated that Rox1 stabilized Mot3 binding to DNA. Integrating these results, we were able to devise a set of rules that govern the combinatorial interactions between Rox1 and Mot3 to achieve differential repression.

The DNA Binding Protein Rfg1 Is a Repressor of Filamentation inCandida albicans

Genetics ◽  
2001 ◽  
Vol 157 (4) ◽  
pp. 1503-1512 ◽  
Author(s):  
Roy A Khalaf ◽  
Richard S Zitomer
Keyword(s):  
Dna Binding ◽  
Binding Protein ◽  
Hyphal Growth ◽  
Dna Binding Protein ◽  
Homozygous Deletion ◽  
Wild Type ◽  
Pathogenic Yeast ◽  
Repression Complex ◽  
Type Gene ◽  
Repression Domain

AbstractWe have identified a repressor of hyphal growth in the pathogenic yeast Candida albicans. The gene was originally cloned in an attempt to characterize the homologue of the Saccharomyces cerevisiae Rox1, a repressor of hypoxic genes. Rox1 is an HMG-domain, DNA binding protein with a repression domain that recruits the Tup1/Ssn6 general repression complex to achieve repression. The C. albicans clone also encoded an HMG protein that was capable of repression of a hypoxic gene in a S. cerevisiae rox1 deletion strain. Gel retardation experiments using the purified HMG domain of this protein demonstrated that it was capable of binding specifically to a S. cerevisiae hypoxic operator DNA sequence. These data seemed to indicate that this gene encoded a hypoxic repressor. However, surprisingly, when a homozygous deletion was generated in C. albicans, the cells became constitutive for hyphal growth. This phenotype was rescued by the reintroduction of the wild-type gene on a plasmid, proving that the hyphal growth phenotype was due to the deletion and not a secondary mutation. Furthermore, oxygen repression of the hypoxic HEM13 gene was not affected by the deletion nor was this putative ROX1 gene regulated positively by oxygen as is the case for the S. cerevisiae gene. All these data indicate that this gene, now designated RFG1 for Repressor of Filamentous Growth, is a repressor of genes required for hyphal growth and not a hypoxic repressor.

Role of the adenovirus 72-kDa DNA binding protein in the rapid decay of early viral mRNA

Virology ◽  
1988 ◽  
Vol 165 (2) ◽  
pp. 438-445 ◽  
Author(s):  
Ianis Lazaridis ◽  
Alexander Babich ◽  
Joseph R. Nevins
Keyword(s):  
Dna Binding ◽  
Binding Protein ◽  
Dna Binding Protein ◽  
Viral Mrna ◽  
Rapid Decay

scholarly journals Zuotin, a putative Z-DNA binding protein in Saccharomyces cerevisiae.

1992 ◽  
Vol 11 (10) ◽  
pp. 3787-3796 ◽  
Author(s):  
S. Zhang ◽  
C. Lockshin ◽  
A. Herbert ◽  
E. Winter ◽  
A. Rich
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Binding ◽  
Binding Protein ◽  
Dna Binding Protein ◽  
Z Dna

scholarly journals FANCJ (BACH1) helicase forms DNA damage inducible foci with replication protein A and interacts physically and functionally with the single-stranded DNA-binding protein

Blood ◽  
2007 ◽  
Vol 110 (7) ◽  
pp. 2390-2398 ◽  
Author(s):  
Rigu Gupta ◽  
Sudha Sharma ◽  
Joshua A. Sommers ◽  
Mark K. Kenny ◽  
Sharon B. Cantor ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Binding ◽  
Binding Protein ◽  
Critical Role ◽  
Protein A ◽  
Replication Protein A ◽  
Dna Binding Protein ◽  
Replication Protein ◽  
Single Stranded Dna

The BRCA1 associated C-terminal helicase (BACH1, designated FANCJ) is implicated in the chromosomal instability genetic disorder Fanconi anemia (FA) and hereditary breast cancer. A critical role of FANCJ helicase may be to restart replication as a component of downstream events that occur during the repair of DNA cross-links or double-strand breaks. We investigated the potential interaction of FANCJ with replication protein A (RPA), a single-stranded DNA-binding protein implicated in both DNA replication and repair. FANCJ and RPA were shown to coimmunoprecipitate most likely through a direct interaction of FANCJ and the RPA70 subunit. Moreover, dependent on the presence of BRCA1, FANCJ colocalizes with RPA in nuclear foci after DNA damage. Our data are consistent with a model in which FANCJ associates with RPA in a DNA damage-inducible manner and through the protein interaction RPA stimulates FANCJ helicase to better unwind duplex DNA substrates. These findings identify RPA as the first regulatory partner of FANCJ. The FANCJ-RPA interaction is likely to be important for the role of the helicase to more efficiently unwind DNA repair intermediates to maintain genomic stability.

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