Dual regulation of the levels and function of Start transcriptional repressors drives G1 arrest in response to cell wall stress
Cell Communication and Signaling,
Год журнала:
2025,
Номер
23(1)
Опубликована: Янв. 16, 2025
Many
different
stress
signaling
pathways
converge
in
a
common
response:
slowdown
or
arrest
cell
cycle
the
G1
phase.
The
G1/S
transition
(called
Start
budding
yeast)
is
key
checkpoint
controlled
by
positive
and
negative
regulators.
Among
them,
Whi7
Whi5
are
transcriptional
repressors
of
program,
yeast
functional
homologs
Retinoblastoma
family
proteins
mammalian
cells.
Under
standard
conditions,
plays
lesser
role
than
inhibition.
However,
under
wall
stress,
induced
more
important
control.
In
this
work,
we
investigated
hallmarks
Whi5,
which
determine
their
strength
as
inhibitors
stress.
response
Saccharomyces
cerevisiae
to
Calcofluor
White
was
characterize
regulation
function
To
control
protein
levels,
used
dose-dependent
β-estradiol-induced
expression
auxin-induced
degron
fusions.
We
also
performed
Chromatin
Immunoprecipitation
assays
investigate
association
with
promoters
scored
re-entry
using
microscopy
assays.
found
that
promoted
specific
upregulation
repressor.
First,
although
increases
not
only
determinant
behind
promoting
arrest.
Indeed,
artificial
induction
at
same
level
resulted
lower
block.
Second,
specifically
recruited
SBF-target
promoters,
independent
increase
its
levels
stage.
Finally,
instability
further
increased
during
degradation
triggered
advanced
re-entry.
Here,
show
enhances
Importantly,
identified
new
Whi7-specific
regulatory
mechanisms
do
operate
Our
results
indicate
cells
may
benefit
from
stress-specific
ensure
stress-induced
rapid
be
particularly
resume
upon
adaptation.
Язык: Английский
Deep learning-driven imaging of cell division and cell growth across an entire eukaryotic life cycle
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2024,
Номер
unknown
Опубликована: Апрель 27, 2024
Abstract
The
life
cycle
of
biomedical
and
agriculturally
relevant
eukaryotic
microorganisms
involves
complex
transitions
between
proliferative
non-proliferative
states
such
as
dormancy,
mating,
meiosis,
cell
division.
New
drugs,
pesticides,
vaccines
can
be
created
by
targeting
specific
stages
parasites
pathogens.
However,
defining
the
structure
a
microbial
often
relies
on
partial
observations
that
are
theoretically
assembled
in
an
ideal
path.
To
create
more
quantitative
approach
to
studying
complete
cycles,
we
generated
deep
learning-driven
imaging
framework
track
across
sexually
reproducing
generations.
Our
combines
microfluidic
culturing,
stage-specific
segmentation
microscopy
images
using
convolutional
neural
networks,
novel
tracking
algorithm,
FIEST,
based
enhancing
overlap
single
masks
consecutive
through
learning
video
frame
interpolation.
As
proof
principle,
used
this
quantitatively
image
compare
growth
regulation
sexual
Saccharomyces
cerevisiae
.
We
developed
fluorescent
reporter
system
fluorescently
labeled
Whi5
protein,
yeast
analog
mammalian
Rb,
new
High-Cdk1
activity
sensor,
LiCHI,
designed
report
during
DNA
replication,
mitosis,
meiotic
homologous
recombination,
meiosis
I,
II.
found
preceded
exit
from
mitotic
G1,
pre-meiotic
G0
spore
state
germination.
A
decrease
total
concentration
characterized
states,
which
is
consistent
with
dilution
model.
nuclear
accumulation
was
developmentally
regulated,
being
at
its
highest
formation.
temporal
coordination
division
not
significantly
different
three
could
characterize
other
single-cell
cycles
remain
incompletely
described.
An
off-the-shelf
user
interface
Yeastvision
provides
free
access
our
processing
algorithms.
Язык: Английский
A non-canonical CDK, Pho85 regulates the restart of the cell-cycle following stress
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2024,
Номер
unknown
Опубликована: Авг. 27, 2024
Abstract
Environmental
stress
induces
an
arrest
of
the
cell
cycle.
Thus,
release
from
this
is
essential
for
survival.
The
cell-cycle-arrest
occurs
via
down
regulation
cyclins
that
drive
main
cyclin
dependent
kinase,
CDK1/Cdc28.
However,
it
was
not
clear
how
cells
escape
potentially
fatal
arrest.
Here
we
show
prior
to
restoration
CDK1/Cdc28
cyclins,
a
non-canonical
CDK,
Pho85,
initiates
cascade
restart
We
demonstrate
following
stress,
Pho85
phosphorylates
Sch9
which
in
turn
directly
transcriptional
inhibitor
Whi5,
yeast
analog
RB1/retinoblastoma,
and
CDK1
target.
This
promotes
Whi5
translocation
nucleus,
stress-induced
at
G
1
phase.
In
addition,
find
parallel
with
also
plays
role
control
Whi5.
Together,
these
findings
provide
insights
into
re-enter
cycle
during
recovery
reveal
CDK
takes
on
roles
acts
pathway
functions
Язык: Английский