scholarly journals The Defect in Transcription-Coupled Repair Displayed by a Saccharomyces cerevisiae rad26 Mutant Is Dependent on Carbon Source and Is Not Associated With a Lack of Transcription

Genetics ◽  
2001 ◽  
Vol 158 (3) ◽  
pp. 989-997
Author(s):  
Miriam Bucheli ◽  
Lori Lommel ◽  
Kevin Sweder

Abstract Nucleotide excision repair (NER) is an evolutionarily conserved pathway that removes DNA damage induced by ultraviolet irradiation and various chemical agents that cause bulky adducts. Two subpathways within NER remove damage from the genome overall or the transcribed strands of transcribing genes (TCR). TCR is a faster repair process than overall genomic repair and has been thought to require the RAD26 gene in Saccharomyces cerevisiae. Rad26 is a member of the SWI/SNF family of proteins that either disrupt chromatin or facilitate interactions between the RNA Pol II and transcription activators. SWI/SNF proteins are required for the expression or repression of a diverse set of genes, many of which are differentially transcribed in response to particular carbon sources. The remodeling of chromatin by Rad26 could affect transcription and/or TCR following formation of DNA damage and other stress-inducing conditions. We speculate that another factor(s) can substitute for Rad26 under particular growth conditions. We therefore measured the level of repair and transcription in two different carbon sources and found that the defect in the rad26 mutant for TCR was dependent on the type of carbon source. Furthermore, TCR did not correlate with transcription rate, suggesting that disruption of RAD26 leads to a specific defect in DNA repair and not transcription.

1992 ◽  
Vol 12 (9) ◽  
pp. 4197-4208
Author(s):  
S Silve ◽  
P R Rhode ◽  
B Coll ◽  
J Campbell ◽  
R O Poyton

Previously, we have shown that the Saccharomyces cerevisiae DNA-binding protein ABF1 exists in at least two different electrophoretic forms (K. S. Sweder, P. R. Rhode, and J. L. Campbell, J. Biol. Chem. 263: 17270-17277, 1988). In this report, we show that these forms represent different states of phosphorylation of ABF1 and that at least four different phosphorylation states can be resolved electrophoretically. The ratios of these states to one another differ according to growth conditions and carbon source. Phosphorylation of ABF1 is therefore a regulated process. In nitrogen-starved cells or in cells grown on nonfermentable carbon sources (e.g., lactate), phosphorylated forms predominate, while in cells grown on fermentable carbon sources (e.g., glucose), dephosphorylated forms are enriched. The phosphorylation pattern is affected by mutations in the SNF1-SSN6 pathway, which is involved in glucose repression-depression. Whereas a functional SNF1 gene, which encodes a protein kinase, is not required for the phosphorylation of ABF1, a functional SSN6 gene is required for itsd ephosphorylation. The phosphorylation patterns that we have observed correlate with the regulation of a specific target gene, COX6, which encodes subunit VI of cytochrome c oxidase. Transcription of COX6 is repressed by growth in medium containing a fermentable carbon source and is derepressed by growth in medium containing a nonfermentable carbon source. COX6 repression-derepression is under the control of the SNF1-SSN6 pathway. This carbon source regulation is exerted through domain 1, a region of the upstream activation sequence UAS6 that binds ABF1 (J. D. Trawick, N. Kraut, F. Simon, and R. O. Poyton, Mol. Cell Biol. 12:2302-2314, 1992). We show that the greater the phosphorylation of ABF1, the greater the transcription of COX6. Furthermore, the ABF1-containing protein-DNA complexes formed at domain 1 differ according to the phosphorylation state of ABF1 and the carbon source on which the cells were grown. From these findings, we propose that the phosphorylation of ABF1 is involved in glucose repression-derepression of COX6 transcription.


2009 ◽  
Vol 30 (2) ◽  
pp. 436-446 ◽  
Author(s):  
Michael Taschner ◽  
Michelle Harreman ◽  
Yumin Teng ◽  
Hefin Gill ◽  
Roy Anindya ◽  
...  

ABSTRACT Upon DNA damage, eukaryotic cells activate a conserved signal transduction cascade known as the DNA damage checkpoint (DDC). We investigated the influence of DDC kinases on nucleotide excision repair (NER) in Saccharomyces cerevisiae and found that repair of both strands of an active gene is affected by Mec1 but not by the downstream checkpoint kinases, Rad53 and Chk1. Repair of the nontranscribed strand (by global genome repair) requires new protein synthesis, possibly reflecting the involvement of Mec1 in the activation of repair genes. In contrast, repair of the transcribed strand by transcription-coupled NER (TC-NER) occurs in the absence of new protein synthesis, and DNA damage results in Mec1-dependent but Rad53-, Chk1-, Tel1-, and Dun1-independent phosphorylation of the TC-NER factor Rad26, a member of the Swi/Snf group of ATP-dependent translocases and yeast homologue of Cockayne syndrome B. Mutation of the Rad26 phosphorylation site results in a decrease in the rate of TC-NER, pointing to direct activation of Rad26 by Mec1 kinase. These findings establish a direct role for Mec1 kinase in transcription-coupled repair, at least partly via phosphorylation of Rad26, the main transcription-repair coupling factor.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Cristina Ribeiro-Silva ◽  
Mariangela Sabatella ◽  
Angela Helfricht ◽  
Jurgen A. Marteijn ◽  
Arjan F. Theil ◽  
...  

Abstract DNA damage sensors DDB2 and XPC initiate global genome nucleotide excision repair (NER) to protect DNA from mutagenesis caused by helix-distorting lesions. XPC recognizes helical distortions by binding to unpaired ssDNA opposite DNA lesions. DDB2 binds to UV-induced lesions directly and facilitates efficient recognition by XPC. We show that not only lesion-binding but also timely DDB2 dissociation is required for DNA damage handover to XPC and swift progression of the multistep repair reaction. DNA-binding-induced DDB2 ubiquitylation and ensuing degradation regulate its homeostasis to prevent excessive lesion (re)binding. Additionally, damage handover from DDB2 to XPC coincides with the arrival of the TFIIH complex, which further promotes DDB2 dissociation and formation of a stable XPC-TFIIH damage verification complex. Our results reveal a reciprocal coordination between DNA damage recognition and verification within NER and illustrate that timely repair factor dissociation is vital for correct spatiotemporal control of a multistep repair process.


2012 ◽  
Vol 196 (6) ◽  
pp. 681-688 ◽  
Author(s):  
Steven Bergink ◽  
Wendy Toussaint ◽  
Martijn S. Luijsterburg ◽  
Christoffel Dinant ◽  
Sergey Alekseev ◽  
...  

The recognition of helix-distorting deoxyribonucleic acid (DNA) lesions by the global genome nucleotide excision repair subpathway is performed by the XPC–RAD23–CEN2 complex. Although it has been established that Rad23 homologs are essential to protect XPC from proteasomal degradation, it is unclear whether RAD23 proteins have a direct role in the recognition of DNA damage. In this paper, we show that the association of XPC with ultraviolet-induced lesions was impaired in the absence of RAD23 proteins. Furthermore, we show that RAD23 proteins rapidly dissociated from XPC upon binding to damaged DNA. Our data suggest that RAD23 proteins facilitate lesion recognition by XPC but do not participate in the downstream DNA repair process.


2007 ◽  
Vol 27 (13) ◽  
pp. 4617-4625 ◽  
Author(s):  
Xuefeng Chen ◽  
Christine Ruggiero ◽  
Shisheng Li

ABSTRACT Rpb9, a nonessential subunit of RNA polymerase II (Pol II), has multiple transcription-related functions in Saccharomyces cerevisiae, including transcription elongation and transcription-coupled repair (TCR). Here we show that, in response to UV radiation, Rpb9 also functions in promoting ubiquitylation and degradation of Rpb1, the largest subunit of Pol II. This function of Rpb9 is not affected by any pathways of nucleotide excision repair, including TCR mediated by Rpb9 itself and by Rad26. Rpb9 is composed of three distinct domains: the N-terminal Zn1, the C-terminal Zn2, and the central linker. The Zn2 domain, which is dispensable for transcription elongation and TCR functions, is essential for Rpb9 to promote Rpb1 degradation, whereas the Zn1 and linker domains, which are essential for transcription elongation and TCR functions, play a subsidiary role in Rpb1 degradation. Coimmunoprecipitation analysis suggests that almost the full length of Rpb9 is required for a strong interaction with the core Pol II: deletion of the Zn2 domain causes dramatically weakened interaction, whereas deletion of Zn1 and the linker resulted in undetectable interaction. Furthermore, we show that Rpb1, rather than the whole Pol II complex, is degraded in response to UV radiation and that the degradation is primarily mediated by the 26S proteasome.


1992 ◽  
Vol 12 (9) ◽  
pp. 4197-4208 ◽  
Author(s):  
S Silve ◽  
P R Rhode ◽  
B Coll ◽  
J Campbell ◽  
R O Poyton

Previously, we have shown that the Saccharomyces cerevisiae DNA-binding protein ABF1 exists in at least two different electrophoretic forms (K. S. Sweder, P. R. Rhode, and J. L. Campbell, J. Biol. Chem. 263: 17270-17277, 1988). In this report, we show that these forms represent different states of phosphorylation of ABF1 and that at least four different phosphorylation states can be resolved electrophoretically. The ratios of these states to one another differ according to growth conditions and carbon source. Phosphorylation of ABF1 is therefore a regulated process. In nitrogen-starved cells or in cells grown on nonfermentable carbon sources (e.g., lactate), phosphorylated forms predominate, while in cells grown on fermentable carbon sources (e.g., glucose), dephosphorylated forms are enriched. The phosphorylation pattern is affected by mutations in the SNF1-SSN6 pathway, which is involved in glucose repression-depression. Whereas a functional SNF1 gene, which encodes a protein kinase, is not required for the phosphorylation of ABF1, a functional SSN6 gene is required for itsd ephosphorylation. The phosphorylation patterns that we have observed correlate with the regulation of a specific target gene, COX6, which encodes subunit VI of cytochrome c oxidase. Transcription of COX6 is repressed by growth in medium containing a fermentable carbon source and is derepressed by growth in medium containing a nonfermentable carbon source. COX6 repression-derepression is under the control of the SNF1-SSN6 pathway. This carbon source regulation is exerted through domain 1, a region of the upstream activation sequence UAS6 that binds ABF1 (J. D. Trawick, N. Kraut, F. Simon, and R. O. Poyton, Mol. Cell Biol. 12:2302-2314, 1992). We show that the greater the phosphorylation of ABF1, the greater the transcription of COX6. Furthermore, the ABF1-containing protein-DNA complexes formed at domain 1 differ according to the phosphorylation state of ABF1 and the carbon source on which the cells were grown. From these findings, we propose that the phosphorylation of ABF1 is involved in glucose repression-derepression of COX6 transcription.


2005 ◽  
Vol 4 (5) ◽  
pp. 861-866 ◽  
Author(s):  
Myoung-Dong Kim ◽  
Seung-Pyo Hong ◽  
Marian Carlson

ABSTRACT In Saccharomyces cerevisiae, Snf1 protein kinase of the Snf1/AMP-activated protein kinase family is required for growth on nonfermentable carbon sources and nonpreferred sugars. Three kinases, Pak1, Elm1, and Tos3, activate Snf1 by phosphorylation of its activation-loop threonine, and the absence of all three causes the Snf− phenotype. No phenotype has previously been reported for the tos3Δ single mutation. We show here that, when cells are grown on glycerol-ethanol, tos3Δ reduces growth rate, Snf1 catalytic activity, and activation of the Snf1-dependent carbon source-responsive element (CSRE) in the promoters of gluconeogenic genes. In contrast, tos3Δ did not significantly affect Snf1 catalytic activity or CSRE function during abrupt glucose depletion, indicating that Tos3 has a more substantial role in activating Snf1 protein kinase during growth on a nonfermentable carbon source than during acute carbon stress. We also report that Tos3 is localized in the cytosol during growth in either glucose or glycerol-ethanol. These findings lend support to the idea that the Snf1 protein kinase kinases make different contributions to cellular regulation under different growth conditions.


Sign in / Sign up

Export Citation Format

Share Document