Nucleic Acids Research,
Год журнала:
2023,
Номер
52(1), С. 259 - 273
Опубликована: Ноя. 22, 2023
Abstract
R-loops
are
three-stranded
nucleic
acid
structures
that
can
cause
replication
stress
by
blocking
fork
progression.
However,
the
detailed
mechanism
underlying
collision
of
DNA
forks
and
remains
elusive.
To
investigate
how
induce
stress,
we
use
single-molecule
fluorescence
imaging
to
directly
visualize
replicating
Phi29
polymerase
(Phi29
DNAp),
simplest
system,
R-loops.
We
demonstrate
a
single
R-loop
block
replication,
blockage
is
more
pronounced
when
an
RNA–DNA
hybrid
on
non-template
strand.
show
this
asymmetry
results
from
secondary
structure
formation
strand,
which
impedes
progression
DNAp.
also
G-quadruplex
displaced
single-stranded
in
enhances
stalling.
Moreover,
observe
between
DNAp
RNA
transcripts
synthesized
T7
(T7
RNAp).
stalling
because
presence
RNAp.
Our
work
provides
insights
into
impede
at
resolution.
Nature,
Год журнала:
2024,
Номер
628(8007), С. 433 - 441
Опубликована: Март 20, 2024
Abstract
An
important
advance
in
cancer
therapy
has
been
the
development
of
poly(ADP-ribose)
polymerase
(PARP)
inhibitors
for
treatment
homologous
recombination
(HR)-deficient
cancers
1–6
.
PARP
trap
PARPs
on
DNA.
The
trapped
are
thought
to
block
replisome
progression,
leading
formation
DNA
double-strand
breaks
that
require
HR
repair
7
Here
we
show
PARP1
functions
together
with
TIMELESS
and
TIPIN
protect
early
S
phase
from
transcription–replication
conflicts.
Furthermore,
synthetic
lethality
deficiency
is
due
an
inability
damage
caused
by
conflicts,
rather
than
PARPs.
Along
these
lines,
inhibiting
transcription
elongation
rendered
HR-deficient
cells
resistant
depleting
small-interfering
RNA
was
lethal
deficiency.
Thus,
enzymatic
activity
may
suffice
efficacy
settings.
Cancers,
Год журнала:
2023,
Номер
15(20), С. 4986 - 4986
Опубликована: Окт. 14, 2023
R-loops
are
unique,
three-stranded
nucleic
acid
structures
that
primarily
form
when
an
RNA
molecule
displaces
one
DNA
strand
and
anneals
to
the
complementary
in
a
double-stranded
molecule.
R-loop
formation
can
occur
during
natural
processes,
such
as
transcription,
which
nascent
remains
hybridized
with
template
strand,
while
non-template
is
displaced.
However,
also
arise
due
many
non-natural
including
damage,
dysregulation
of
degradation
pathways,
defects
processing.
Despite
their
prevalence
throughout
whole
genome,
predominantly
found
actively
transcribed
gene
regions,
enabling
serve
seemingly
controversial
roles.
On
hand,
pathological
accumulation
contributes
genome
instability,
hallmark
cancer
development
plays
role
tumorigenesis,
progression,
therapeutic
resistance.
other
play
critical
roles
regulating
essential
expression,
chromatin
organization,
class-switch
recombination,
mitochondrial
replication,
repair.
In
this
review,
we
summarize
discoveries
related
formation,
suppression,
removal
influence
on
repair,
oncogenic
events.
We
have
discussed
therapeutical
opportunities
by
targeting
R-loops.
EMBO Reports,
Год журнала:
2024,
Номер
25(3), С. 1387 - 1414
Опубликована: Фев. 12, 2024
Abstract
Understanding
how
chromatin
organisation
is
duplicated
on
the
two
daughter
strands
a
central
question
in
epigenetics.
In
mammals,
following
passage
of
replisome,
nucleosomes
lose
their
defined
positioning
and
transcription
contributes
to
re-organisation.
However,
whether
plays
greater
role
organization
DNA
replication
remains
unclear.
Here
we
analysed
protein
re-association
with
newly
replicated
upon
inhibition
using
iPOND
coupled
quantitative
mass
spectrometry.
We
show
that
nucleosome
assembly
re-establishment
most
histone
modifications
are
uncoupled
from
transcription.
RNAPII
acts
promote
hundreds
proteins
via
pathways
not
observed
steady-state
chromatin.
These
include
ATP-dependent
remodellers,
factors
methyltransferases.
also
identify
set
repair
may
handle
transcription-replication
conflicts
during
normal
human
non-transformed
cells.
Our
study
reveals
post-replication
than
previously
anticipated.
Annual Review of Biochemistry,
Год журнала:
2024,
Номер
93(1), С. 21 - 46
Опубликована: Апрель 10, 2024
DNA
replication
and
transcription
occur
in
all
living
cells
across
domains
of
life.
Both
essential
processes
simultaneously
on
the
same
template,
leading
to
conflicts
between
macromolecular
machines
that
perform
these
functions.
Numerous
studies
over
past
few
decades
demonstrate
this
is
an
inevitable
problem
both
prokaryotic
eukaryotic
cells.
We
have
learned
lead
fork
reversal,
breaks
DNA,
R-loop
formation,
topological
stress,
mutagenesis
can
ultimately
impact
evolution.
Recent
also
provided
insight
into
various
mechanisms
mitigate,
resolve,
allow
tolerance
how
result
pathological
consequences
divergent
species.
In
review,
we
summarize
our
current
knowledge
regarding
outcomes
encounters
machineries
explore
clashes
are
dealt
with
Genes & Development,
Год журнала:
2024,
Номер
unknown
Опубликована: Июль 10, 2024
Genome
integrity
relies
on
the
accuracy
of
DNA
metabolism,
but
as
appreciated
for
more
than
four
decades,
transcription
enhances
mutation
and
recombination
frequencies.
More
recent
research
provided
evidence
a
previously
unforeseen
link
between
RNA
which
is
often
related
to
accumulation
DNA–RNA
hybrids
R-loops.
In
addition
physiological
roles,
R-loops
interfere
with
replication
repair,
providing
molecular
scenario
origin
genome
instability.
Here,
we
review
current
knowledge
multiple
factors
that
prevent
or
resolve
consequent
transcription–replication
conflicts
thus
act
modulators
dynamics.
Nucleic Acids Research,
Год журнала:
2024,
Номер
52(17), С. 10355 - 10369
Опубликована: Авг. 9, 2024
Abstract
Replication
forks
stalled
at
co-transcriptional
R-loops
can
be
restarted
by
a
mechanism
involving
fork
cleavage-religation
cycles
mediated
MUS81
endonuclease
and
DNA
ligase
IV
(LIG4),
which
presumably
relieve
the
topological
barrier
generated
transcription-replication
conflict
(TRC)
facilitate
ELL-dependent
reactivation
of
transcription.
Here,
we
report
that
restart
R-loop-stalled
replication
via
MUS81-LIG4-ELL
pathway
requires
senataxin
(SETX),
helicase
unwind
RNA:DNA
hybrids.
We
found
SETX
promotes
progression
preventing
R-loop
accumulation
during
S-phase.
Interestingly,
loss
activity
leads
to
nascent
degradation
upon
induction
R-loop-mediated
stalling
hydroxyurea.
This
phenotype
is
independent
reversal
results
from
DNA2-mediated
resection
MUS81-cleaved
accumulate
due
defective
restart.
Finally,
demonstrate
acts
in
common
with
DEAD-box
DDX17
suppress
stress
human
cells.
A
possible
cooperation
between
these
RNA/DNA
helicases
unwinding
TRC
sites
discussed.