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Molecular and Cellular Biology, December 2001, p. 8651-8656, Vol. 21, No. 24
0270-7306/01/$04.00+0 DOI: 10.1128/MCB.21.24.8651-8656.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
Requirement for Yeast RAD26, a Homolog of the Human
CSB Gene, in Elongation by RNA Polymerase
II
Sung-Keun
Lee,
Sung-Lim
Yu,
Louise
Prakash, and
Satya
Prakash*
Sealy Center for Molecular Science,
University of Texas Medical Branch, Galveston, Texas 77555-1061
Received 21 August 2001/Returned for modification 12 September
2001/Accepted 19 September 2001
 |
ABSTRACT |
Mutations in the human CSB gene cause Cockayne syndrome
(CS). In addition to increased photosensitivity, CS patients
suffer from severe developmental abnormalities, including growth
retardation and mental retardation. Whereas a deficiency in the
preferential repair of UV lesions from the transcribed strand accounts
for the increased photosensitivity of CS patients, the reason for developmental defects in these individuals has remained unclear. Here
we provide in vivo evidence for a role of RAD26, the
counterpart of the CSB gene in Saccharomyces
cerevisiae, in transcription elongation by RNA polymerase II, and
in addition we show that under conditions requiring rapid synthesis of
new mRNAs, growth is considerably reduced in cells lacking
RAD26. These findings implicate a role for CSB in
transcription elongation, and they strongly suggest that impaired
transcription elongation is the underlying cause of the developmental
problems in CS patients.
| |
INTRODUCTION |
Cockayne syndrome (CS) in
humans is characterized by severe growth retardation that has the
outward appearance of cachetic dwarfism, and CS patients suffer from
progressive neurologic dysfunction and mental retardation. CS
individuals also exhibit mild sun sensitivity, but they do not suffer
from the increased incidence of skin cancers so prevalent in xeroderma
pigmentosum patients. The mean age of death in CS patients is ~12
years (13). Mutations in two human genes, CSA
and CSB, account for over 90% of CS cases (8).
CS cells are impaired in their ability to perform preferential repair of DNA lesions from the transcribed strand (21), a
phenomenon known as transcription-coupled repair (TCR)
(11). Although the defect in preferential repair of UV
lesions from the transcribed strand explains the photosensitivity of CS
patients, it fails to account for the characteristic growth and
neurological defects associated with CS.
RAD26 is the CSB counterpart in
Saccharomyces cerevisiae, and inactivation of this gene
causes a defect in the TCR of UV-damaged DNA (20). The
proteins encoded by the RAD26 and CSB genes are members of the SWI2/SNF2 family of ATPases, and both proteins have
DNA-dependent ATPase activities (6, 17). Interestingly, in
vitro studies with the purified human CSB protein have suggested a role
for CSB as an RNA polymerase II (Pol II) elongation factor (16). Here we utilize S. cerevisiae as a model
to investigate the role of RAD26 in transcription elongation
in vivo and to examine the possibility that the clinical features of CS
patients derive from defects in transcription elongation.
Elongation factor SII enables Pol II to transcribe through intrinsic
arrest sites in DNA. SII binds arrested Pol II and activates the
cleavage of nascent transcript by a latent endoribonuclease intrinsic
to Pol II, which eventually results in the clearance of the impediment
(15). In S. cerevisiae, DST1, the gene encoding SII, is not essential for viability; however, the dst1
mutant exhibits enhanced sensitivity to the base analog 6-azauracil
(6AU) (12), which depletes cellular levels of the RNA
precursors GTP and UTP (5). Because of the decrease in
nucleoside triphosphate concentrations in 6AU-treated cells, the
elongation rate of Pol II is lowered and it suffers more arrest. SII
releases Pol II from the arrested state and enables it to resume
elongation. Yeast cells that lack SII and, additionally, that harbor a
conditional mutation in RPB2, the gene encoding the second
largest subunit of Pol II and which confers a 6AU-sensitive phenotype,
also manifest an elongation defect in biochemical assays in vitro
(14) and exhibit reduced levels of specific mRNAs
following 6AU treatment (9). Thus, efficient mRNA
synthesis in vivo is dependent on an optimally functioning elongation machinery.
Since CS patients are viable and the rad26 mutant
displays no growth defects under normal conditions, inactivation of
RAD26 in yeast or of CSB in humans may confer
only a subtle defect in transcription. To be able to discern any such
changes in the rate of transcription, we combined the
rad26 mutation with the elongation-defective dst1 mutation. The underlying assumption here was that if
Rad26 functions independently of SII in transcription elongation, then a more severe phenotype would result upon the simultaneous loss of both
proteins. Also, we examined the mRNA levels of genes that were in a
state of high transcriptional activity because any transcriptional deficiency may then become more apparent. Here we provide evidence for
a role of RAD26 in the elongation phase of Pol II
transcription in vivo and show that, in the absence of
RAD26, growth impairment results under conditions requiring
new mRNA synthesis.
| |
MATERIALS AND METHODS |
Yeast strains.
In this study, the wild-type strain EMY73
(MATa his3-1 leu2-3,-112
trp1) and its isogenic derivative strains YR26.1, YR26.7, and
YRP127 carrying the rad26, rad26
dst1, and dst1 mutations, respectively,
were used. In the rad26 mutant, amino acids 21 to 1009 of
the 1,085-amino-acid RAD26-encoded protein are deleted, and
in the dst1 mutant, amino acids 33 to 226 of the
309-amino-acid DST1-encoded protein are deleted.
Transcription analyses.
For the examination of
GAL7 and GAL10 transcription, cells were grown at
30°C in YPL (1% yeast extract, 2% peptone, 3.7% lactate) medium to
saturation. The cells were diluted in the identical fresh medium to an
optical density at 600 nm (OD600) of 0.5 with a final
concentration of 2% galactose. Samples were removed at the time points
indicated in Fig. 1 after being transferred to galactose-containing medium. Cells were pelleted and quickly frozen in
crushed dry ice. Frozen cells were maintained at 
80°C until RNA isolation.
To examine GAL gene transcription in the presence of 6AU,
cells were grown to log phase at 30°C in synthetic complete (SC) medium containing 3% glycerol-2% lactate and lacking uracil. Cells were harvested by centrifugation and resuspended in the identical fresh
medium with 100 µg of 6AU/ml. Following incubation in 6AU for 2 h at 30°C, galactose was added to reach a final concentration of 2%.
Samples were removed at the time points indicated in Fig. 3B after the
addition of galactose. Cells were pelleted and quickly frozen in
crushed dry ice. Frozen cells were maintained at 80°C until RNA isolation.
For the examination of transcription of the
PHO5 gene, YP
(1% yeast extract, 2% peptone) medium containing a high or low
concentration
of phosphate (P
i) was prepared as described
previously (
7).
Cells were grown to log phase at 30°C in
YP-high-P
i medium. Cells
were harvested by centrifugation,
washed twice with distilled
water, and diluted in
YP-low-P
i medium to an OD
600 of 0.5. Samples
were removed at the indicated time after being transferred to
YP-low-P
i medium. Cells were pelleted and quickly frozen
in crushed
dry ice. Frozen cells were maintained at
80°C until RNA
isolation.
Total RNA was isolated using the hot phenol method
(
1a) and fractionated by electrophoresis on 1.4%
agarose-6% formaldehyde
gels. RNA was transferred to Hybond nylon
membranes (Amersham).
Each DNA probe was
32P labeled by the
Multiprime DNA-labeling system (Amersham). Hybridization
was
performed at 42°C in 40% formamide-5% dextran sulfate-1%
sodium
dodecyl sulfate (SDS)-5× SSC (1× SSC is 0.15 M NaCl plus
0.015
M sodium citrate)-5× Denhardt's solution-1 M KPO
4
containing 100
µg of denatured herring sperm DNA/ml. The blots were
washed twice
with 2× SSC-0.1% SDS for 5 and 10 min at room
temperature, once
with 0.5× SSC-0.1% SDS for 30 min at 50°C, and
once with 0.1×
SSC-0.1% SDS for 15 min at 50°C. Quantitation of
mRNA levels was
performed in a PhosphorImager using ImageQuant
software.
Determination of growth.
Cells were grown on YPD (1% yeast
extract, 2% peptone, 2% dextrose) plates and diluted in YPL medium to
an OD600 of 0.05. The cultures were then split, and half of
the culture was left at 30°C while the other half was shifted to
37°C. Cell density (OD600) was determined at the time
points indicated in Fig. 2.
| |
RESULTS |
Effect of rad26 mutation on inducible synthesis of
mRNAs.
To investigate the role of RAD26 in
transcription, we examined the inducible synthesis of GAL7
and GAL10 mRNAs and of PHO5 mRNA in the wild-type
and rad26, dst1, and rad26
dst1 mutant strains. Transcription of these
GAL genes, which is induced upon the addition of galactose,
was lowered in the rad26 mutant (Fig. 1). Transcription was also affected in
the dst1 strain but to a lesser degree than in the
rad26 strain. The most severe reduction in transcription
occurred when the rad26 mutation was combined with the
dst1 mutation. Transcription of the PHO5 gene,
which is induced when phosphate is limiting in the medium, was also reduced in the rad26 strain. For PHO5,
transcription impairment was greater in the dst1 strain
than in the rad26 strain, and for this gene also, mRNA
levels became more severely depressed in the rad26
dst1 double mutant strain than in the rad26
or dst1 single mutant strain (Fig. 1). For example, the
levels of PHO5 transcripts at 5 h were reduced to 85, 70, and 34% in the rad26, dst1, and
rad26 dst1 strains, respectively, compared to that in the wild-type strain, indicating that a synergistic decline
in PHO5 transcription occurs in the double mutant (Fig. 1B).
In summary, for all three genes examined, deletion of RAD26 reduces the levels of their encoded mRNAs and a more severe reduction in transcription occurs in the absence of both SII and Rad26 proteins.
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FIG. 1.
Transcription of GAL7, GAL10, and
PHO5 genes in wild-type (W.T.) and rad26,
dst1, and rad26 dst1 mutant
strains. Total RNAs from cells grown in YPL medium containing galactose
were subjected to Northern analysis. (A) Transcript levels of
GAL7 (top left panel), GAL10 (middle left panel),
and PHO5 (top right panel) genes. The ethidium
bromide-stained gel shown in the bottom right panel indicates the
levels of RNAs loaded for PHO5, and that which is shown in
the bottom left panel indicates the levels of RNAs loaded for the
GAL genes. mRNA levels were examined at the indicated times
after cells were transferred to galactose-containing medium or to
low-phosphate medium. (B) Quantitation of GAL7, GAL10, and
PHO5 mRNA levels. mRNA units at each time point are relative
to the highest mRNA level in the wild-type strain. Symbols:  , wild
type;  , rad26;  , dst1;  ,
rad26 dst1.
|
|
Synergistic enhancement of growth defects in the
rad26 dst1 double mutant.
Although
the rad26 mutation has no discernible effect on growth in
rich medium (YPD or SC medium), the requirement of RAD26 for
efficient transcription suggested that growth impairment might become
more apparent under conditions requiring rapid synthesis of new mRNAs.
To investigate such a possibility, the wild-type and
rad26, dst1, and rad26
dst1 mutant strains were transferred from glucose to
lactate medium and grown at 30 and 37°C. At 30°C, growth was not
significantly affected by the dst1 mutation but the
rad26 strain grew at a lower rate than did the wild-type or the dst1 strain, and a slight further decrease in
growth was noted in the rad26 dst1 strain
(Fig. 2A). The growth defects, however,
became much more striking at 37°C, presumably because under these
conditions, in addition to the change in the carbon source, cells have
to adapt to the exigencies of high temperature. At 37°C, growth was
retarded in both the rad26 and dst1 strains but the dst1 mutation had a more pronounced debilitating
effect on growth than did the rad26 mutation and the
rad26 dst1 strain barely grew (Fig. 2B). A
comparison of OD600s at 50 h shows that cell density
was reduced to 65, 45, and 22% in the rad26,
dst1, and rad26 dst1 strains,
respectively, compared to that in the wild-type strain (Fig. 2B). Thus,
a synergistic decline in cell density occurs in the rad26
dst1 double mutant strain. The extreme growth defect of
the rad26 dst1 double mutant most likely
stems from the more severe transcriptional defect in the absence of both the Rad26 and SII proteins.
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FIG. 2.
Growth of wild-type () and rad26 (),
dst1 (), and rad26 dst1
() mutant strains. Cells were grown on YPD plates and diluted in YPL
medium to an OD600 of 0.05. Half of the culture was left at
30°C (A), the other half was shifted to 37°C (B), and cell density
(OD600) was determined at the indicated time points.
|
|
Reduced mRNA levels in 6AU-treated rad26 mutant
cells.
Since nucleotide depletion occurring in the presence of 6AU
affects the elongation efficiency of Pol II, sensitivity to 6AU has
been exploited as a means for identifying elongation factors. Thus,
mutations in SII or in the RPB2 subunit of Pol II, defective in
transcription elongation, yield a 6AU-sensitive phenotype
(9). In the presence of 6AU, growth is impaired in the
rad26 strain (Fig. 3A).
Also, the transcriptional defect of the
rad26 strain was further enhanced upon 6AU treatment, as
the levels of GAL7 and GAL10 mRNAs suffered more
drastic reductions in 6AU-treated rad26 cells (Fig. 3B)
than in untreated cells (Fig. 1). In Table 1, we show the levels of GAL7
and GAL10 mRNAs in 6AU-treated and untreated
rad26 cells relative to those in the wild-type strain.
While transcription is affected in untreated rad26 cells, the transcriptional defect becomes more pronounced in 6AU-treated rad26 cells. For example, in the 60-min samples,
GAL7 and GAL10 mRNA levels in untreated
rad26 cells were about 70% of the levels in the
wild-type strain, whereas in 6AU-treated rad26 cells, these mRNA levels were reduced to about 30% of the levels in wild-type cells.
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FIG. 3.
Inhibition of growth and transcription in
6AU-treated rad26 cells. W. T., wild type. (A)
Growth of wild-type and rad26 mutant cells in the absence
or presence of 6AU. Wild-type and rad26 mutant cells were
grown on YPD plates in the absence of 6AU (top panels), on SC medium
lacking uracil and in the absence of 6AU (middle panels), or on SC
medium lacking uracil but containing 50 µg of 6AU/ml (bottom panels).
(B) Transcription of GAL7 and GAL10 genes in the
presence of 6AU. Cells grown to log phase at 30°C in SC medium
containing 3% glycerol and 2% lactate and lacking uracil were
harvested and resuspended in the identical fresh medium with 100 µg
of 6AU/ml. After incubation for 2 h at 30°C, galactose was added
to reach a final concentration of 2%. Samples were removed at the
indicated time points after the addition of galactose, and
GAL7 (top) and GAL10 (middle) mRNA levels were
examined. The ethidium bromide-stained gel shown in the bottom panel
indicates the levels of RNAs loaded. The time points indicate the
period in minutes after the addition of galactose to the medium. (C)
mRNA levels of TRP3, URA3, and STE3 in wild-type
and rad26 mutant cells treated with 6AU. Cells grown to
log phase at 30°C in SC medium lacking uracil were diluted in
identical fresh medium to an OD600 of 0.5, and 6AU was
added to reach a final concentration of 75 µg/ml. Samples were
removed at the indicated time points after the addition of 6AU. The
ethidium bromide-stained gel shown in the bottom panel indicates the
levels of RNAs loaded. (D) Quantitation of TRP3, URA3, and
STE3 mRNAs in the presence of 6AU. mRNA units at each time
point are relative to the highest mRNA level in the wild-type strain.
Symbols:  , wild type; , rad26 mutant.
|
|
Following 6AU treatment, steady-state levels of mRNAs, such as those
made by genes involved in amino acid biosynthesis, declined
in the
elongation-defective
dst1 rpb2-10 double
mutant, while
the wild-type cells maintained near-normal levels of
these mRNAs
(
9). In wild-type yeast cells treated with 6AU
for up to 1
h, steady-state levels of
TRP3 mRNA also
remained unchanged, whereas
in the similarly treated
rad26 cells, these mRNA levels were
reduced to
approximately 50% of wild-type levels (Fig.
3C and
D). 6AU reduces
intracellular GTP and UTP levels by inhibiting
the enzymes IMP
dehydrogenase and orotidylate decarboxylase, respectively.
Upon 6AU
treatment, wild-type yeast cells induce transcription
of
PUR5, a gene that encodes IMP dehydrogenase. The capacity to
induce
PUR5 transcription, however, is greatly reduced in
yeast
cells deficient in transcription elongation machinery, such as
those harboring the
dst1 mutation or the
rpb2-10 mutation (
18).
These and other results
have suggested that yeast cells respond
to nucleotide depletion by
transcriptional induction of genes
involved in nucleotide biosynthesis
and that this induction is
somehow coupled to efficient elongation
(
18). The levels of
mRNAs made by the
URA3
gene, which encodes orotidylate decarboxylase,
also increase in
wild-type cells treated with 6AU for 30 min;
by contrast, only a slight
increase was evident in
rad26 mutant
cells treated
similarly (Fig.
3C and D). Also, the mRNA levels
of the
STE3
gene increased almost 10-fold in wild-type cells treated
with 6AU for
30 min, wherease there was little increase in
rad26 mutant cells (Fig.
3C and
D).
| |
DISCUSSION |
Here we show that transcription of the three inducible genes
examined, GAL7, GAL10, and PHO5, is reduced in
the absence of Rad26 or SII protein and that this transcriptional
defect becomes more severe in cells lacking both of these proteins.
Moreover, the rad26 mutation confers sensitivity to 6AU,
a sensitive indicator of transcription elongation defect, and compared
to the wild-type strain, GAL7 and GAL10 mRNA
levels were more severely depressed in 6AU-treated rad26
cells than in untreated cells. The steady-state levels of TRP3,
URA3, and STE3 mRNAs were also much lower in
6AU-treated rad26 cells than in similarly treated
wild-type cells. Additionally, under conditions requiring new mRNA
synthesis, growth is affected in cells lacking Rad26 or SII and a
further inhibition of growth occurs in the absence of both Rad26 and
SII. Together, these observations implicate a role for RAD26
in transcription elongation and suggest that Rad26 and SII contribute
independently to this process.
Because of the lack of isogenicity of CSB-deficient cell lines, studies
such as those reported here would be difficult to conduct with humans,
since any effect on transcription may be due to differences in the
genetic backgrounds of different cell lines. Also, in view of the fact
that inactivation of CSB is not lethal, we expect the effect of the CSB
protein on transcription elongation to be subtle and possibly limited
to particular genes. Therefore, it is not surprising that studies of
transcription in CSB-deficient cells have yielded conflicting results.
Thus, while in one study, Pol II transcription was reported to be lower in some CSB-deficient cell lines than it was in normal cells
(2), in another study, there was no difference in the
levels of transcription supported by extracts of normal, CSA, or CSB
cells when undamaged DNA was used as the template (4). In
another study, microinjection of antibodies against the CSA or CSB
proteins also had no effect on the overall level of transcription in
unirradiated cultured fibroblasts (19).
In addition to increased photosensitivity, individuals suffering from
CS exhibit developmental defects such as severe growth retardation,
mental retardation, neurodysmyelination, and skeletal and retinal
abnormalities (13). The high degree of conservation of
Rad26 and CSB proteins strongly suggests that the two proteins act
similarly in S. cerevisiae and humans, respectively. Thus, from our observations with RAD26 in S. cerevisiae, we deduce a role for CSB in Pol
II-dependent transcription elongation and suggest that the various
developmental defects in CSB-deficient individuals accrue from defects
in transcription. In humans, p53 levels rise in response to
transcription inhibition and cell death is associated with prolonged
induction of p53 (1). p53-dependent apoptosis resulting
from deficiencies in transcription elongation would further contribute
to developmental defects in CS.
Recently, based upon the findings that the TCR of oxidative
lesions 8-oxoguanine and thymine glycol is defective in CS
cells, failure to repair oxidative damage from the transcribed strand was suggested to be the basis of developmental defects in CS (3, 10). Our results showing the involvement of the RAD26
gene in Pol II transcription elongation in the absence of any exogenous DNA damage and the finding that, under conditions requiring new mRNA
synthesis, growth impairment occurs in the absence of RAD26 imply, however, that developmental defects in CS patients arise from
defects in transcription elongation and not from faulty DNA repair.
Although the in vivo evidence for a role of CSB in the elongation step
of Pol II transcription is lacking, purified CSB protein stimulates the
rate of elongation by Pol II on oligo(dC)-tailed DNA templates in the
absence of additional transcription factors (16). These in
vitro biochemical studies with the CSB protein support in vivo studies
with the RAD26 gene in S. cerevisiae and they
suggest a direct role for Rad26 and CSB proteins in transcriptional elongation by Pol II. The DNA-dependent ATPase activity of these proteins (6, 17) may promote passage of Pol II through a variety of transcriptional impediments, including intrinsic arrest sites in DNA.
Loss of CSB in humans induces metaphase fragility of four loci,
RNU1, PSU1, RNU2, and RN5S, that are highly
transcriptionally active (22). RNU1 and
RNU2 contain tandemly repeated U1 and U2 snRNA genes,
respectively, PSU1 contains U1 pseudogenes, and RN5S contains tandemly repeated 5S rRNA genes. U1 and U2
snRNAs are transcribed by Pol II, and 5S rRNA is transcribed by Pol
III. Transcription of highly structured RNAs, like U1 and U2 snRNA and
5S rRNA, might require the activity of elongation factors like CSB. In
the absence of CSB, the presence of stalled RNA polymerases on DNA may
block chromatin condensation, causing localized chromosome fragility at
metaphase (22). Since the absence of CSB causes fragility
of genes transcribed by Pol II and Pol III, CSB may function as an
elongation factor for Pol III as well.
| |
ACKNOWLEDGMENT |
This work was supported by National Institutes of Health grant CA35035.
| |
FOOTNOTES |
*
Corresponding author. Mailing address: Sealy Center for
Molecular Science, University of Texas Medical Branch, 6.104 Blocker Medical Research Building, 11th and Mechanic Streets, Galveston, TX
77555-1061. Phone: (409) 747-8602. Fax: (409) 747-8608. E-mail: sprakash{at}scms.utmb.edu.
| |
REFERENCES |
| 1.
|
Andrea, L., and B. Wasylyk.
1997.
Transcription abnormalities potentiate apoptosis of normal human fibroblasts.
Mol. Med.
3:852-863[Medline].
|
| 1a.
|
Ausubel, F. M. (ed.).
1993.
Current protocols in molecular biology, vol. 2, unit 13.12.
Wiley, New York, N.Y.
|
| 2.
|
Balajee, A. S.,
A. May,
G. L. Dianov,
E. C. Friedberg, and V. A. Bohr.
1997.
Reduced RNA polymerase II transcription in intact and permeabilized Cockayne syndrome group B cells.
Proc. Natl. Acad. Sci. USA
94:4306-4311[Abstract/Free Full Text].
|
| 3.
|
Cooper, P. K.,
T. Nouspikel,
S. G. Clarkson, and S. A. Leadon.
1997.
Defective transcription-coupled repair of oxidative base damage in Cockayne syndrome patients from XP group G.
Science
275:990-993[Abstract/Free Full Text].
|
| 4.
|
Dianov, G. L.,
J.-F. Houle,
N. Iyer,
V. A. Bohr, and E. C. Friedberg.
1997.
Reduced RNA polymerase II transcription in extracts of Cockayne syndrome and xeroderma pigmentosum/Cockayne syndrome cells.
Nucleic Acids Res.
25:3636-3642[Abstract/Free Full Text].
|
| 5.
|
Exinger, F., and F. Lacroute.
1992.
6-Azauracil inhibition of GTP biosynthesis in Saccharomyces cerevisiae.
Curr. Genet.
22:9-11[CrossRef][Medline].
|
| 6.
|
Guzder, S. N.,
Y. Habraken,
P. Sung,
L. Prakash, and S. Prakash.
1996.
RAD26, the yeast homolog of human Cockayne's syndrome group B gene, encodes a DNA dependent ATPase.
J. Biol. Chem.
271:18314-18317[Abstract/Free Full Text].
|
| 7.
|
Han, M.,
U.-J. Kim,
P. Kayne, and M. Grunstein.
1988.
Depletion of histone H4 and nucleosomes activates the PHO5 gene in Saccharomyces cerevisiae.
EMBO J.
7:2221-2228[Medline].
|
| 8.
|
Hanawalt, P. C.
2000.
The bases for Cockayne syndrome.
Nature
405:415-416[CrossRef][Medline].
|
| 9.
|
Lennon, J. C., III,
M. Wind,
L. Saunders,
M. B. Hock, and D. Reines.
1998.
Mutations in RNA polymerase II and elongation factor SII severely reduce mRNA levels in Saccharomyces cerevisiae.
Mol. Cell. Biol.
18:5771-5779[Abstract/Free Full Text].
|
| 10.
|
Le Page, F.,
E. E. Kwoh,
A. Avrutskaya,
A. Gentil,
S. A. Leadon,
A. Sarasin, and P. K. Cooper.
2000.
Transcription-coupled repair of 8-oxoguanine: requirement for XPG, TFIIH, and CSB and implications for Cockayne syndrome.
Cell
101:159-171[CrossRef][Medline].
|
| 11.
|
Mellon, I.,
G. Spivak, and P. C. Hanawalt.
1987.
Selective removal of transcription-blocking DNA damage from the transcribed strand of the mammalian DHFR gene.
Cell
51:241-249[CrossRef][Medline].
|
| 12.
|
Nakanishi, T.,
M. Shimoaraiso,
T. Kubo, and S. Natori.
1995.
Structure-function relationship of yeast S-II in terms of stimulation of RNA polymerase II, arrest relief, and suppression of 6-azauracil sensitivity.
J. Biol. Chem.
270:8991-8995[Abstract/Free Full Text].
|
| 13.
|
Nance, M. A., and S. A. Berry.
1992.
Cockayne syndrome: review of 140 cases.
Am. J. Med. Gen.
42:68-84[CrossRef][Medline].
|
| 14.
|
Powell, W., and D. Reines.
1996.
Mutations in the second largest subunit of RNA polymerase II cause 6-azauracil sensitivity in yeast and increased transcriptional arrest in vitro.
J. Biol. Chem.
271:6866-6873[Abstract/Free Full Text].
|
| 15.
|
Reines, D.
1994.
Nascent RNA cleavage by transcription elongation complexes, p. 263-278.
In
R. C. Conaway, and J. W. Conaway (ed.), Transcription: mechanisms and regulation. Raven Press, Ltd., New York, N.Y.
|
| 16.
|
Selby, C. P., and A. Sancar.
1997.
Cockayne syndrome group B protein enhances elongation by RNA polymerase II.
Proc. Natl. Acad. Sci. USA
94:11205-11209[Abstract/Free Full Text].
|
| 17.
|
Selby, C. P., and A. Sancar.
1997.
Human transcription-repair coupling factor CSB/ERCC6 is a DNA-stimulated ATPase but is not a helicase and does not disrupt the ternary transcription complex of stalled RNA polymerase II.
J. Biol. Chem.
272:1885-1890[Abstract/Free Full Text].
|
| 18.
|
Shaw, R. J., and D. Reines.
2000.
Saccharomyces cerevisiae transcription elongation mutants are defective in PUR5 induction in response to nucleotide depletion.
Mol. Cell. Biol.
20:7427-7437[Abstract/Free Full Text].
|
| 19.
|
van Gool, A. J.,
E. Citterio,
S. Rademakers,
R. van Os,
W. Vermeulen,
A. Constantinou,
J.-M. Egly,
D. Bootsma, and J. H. J. Hoeijmakers.
1997.
The Cockayne syndrome B protein, involved in transcription-coupled DNA repair, resides in an RNA polymerase II-containing complex.
EMBO J.
16:5955-5965[CrossRef][Medline].
|
| 20.
|
van Gool, A. J.,
R. Verhage,
S. M. A. Swagemakers,
P. van de Putte,
J. Brouwer,
C. Troelstra,
D. Bootsma, and J. H. J. Hoeijmakers.
1994.
RAD26, the functional S. cerevisiae homolog of the Cockayne syndrome B gene ERCC6.
EMBO J.
13:5361-5369[Medline].
|
| 21.
|
van Hoffen, A.,
A. T. Natarajan,
L. V. Mayne,
A. A. van Zeeland,
L. H. F. Mullenders, and J. Venema.
1993.
Deficient repair of the transcribed strand of active genes in Cockayne's syndrome cells.
Nucleic Acids Res.
21:5890-5895[Abstract/Free Full Text].
|
| 22.
|
Yu, A.,
H.-Y. Fan,
D. Liao,
A. D. Bailey, and A. M. Weiner.
2000.
Activation of p53 or loss of the Cockayne syndrome group B repair protein causes metaphase fragility of human U1, U2, and 5S genes.
Mol. Cell
5:801-810[CrossRef][Medline].
|
Molecular and Cellular Biology, December 2001, p. 8651-8656, Vol. 21, No. 24
0270-7306/01/$04.00+0 DOI: 10.1128/MCB.21.24.8651-8656.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
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Abstract
Introduction
