Research Square (Research Square),
Год журнала:
2024,
Номер
unknown
Опубликована: Апрель 9, 2024
Abstract
Phosphorylation
of
substrates
by
cyclin-dependent
kinases
(CDKs)
is
the
driving
force
cell
cycle
progression.
Several
CDK-activating
cyclins
are
involved,
yet
how
they
contribute
to
substrate
specificity
still
poorly
understood.
Here,
we
discovered
that
a
positively
charged
pocket
in
cyclin
B1,
which
exclusively
conserved
within
B-type
and
binds
phosphorylated
serine-
or
threonine-residues,
essential
for
correct
execution
mitosis.
HeLa
cells
expressing
mutant
B1
strongly
delayed
anaphase
onset
due
multiple
defects
mitotic
spindle
function
timely
activation
E3
ligase
APC/C.
Pocket
integrity
APC/C
phosphorylation
particularly
at
non-consensus
CDK1
sites
full
vitro
ubiquitylation
activity.
Our
results
support
model
B1’s
serves
as
site
factor
sequential
phosphorylations
involving
initial
priming
events
facilitate
subsequent
pocket-dependent
even
motifs.
Nature Communications,
Год журнала:
2025,
Номер
16(1)
Опубликована: Янв. 20, 2025
Abstract
Phosphorylation
of
substrates
by
cyclin-dependent
kinases
(CDKs)
is
the
driving
force
cell
cycle
progression.
Several
CDK-activating
cyclins
are
involved,
yet
how
they
contribute
to
substrate
specificity
still
poorly
understood.
Here,
we
discover
that
a
positively
charged
pocket
in
cyclin
B1,
which
exclusively
conserved
within
B-type
and
binds
phosphorylated
serine-
or
threonine-residues,
essential
for
correct
execution
mitosis.
HeLa
cells
expressing
mutant
B1
strongly
delayed
anaphase
onset
due
multiple
defects
mitotic
spindle
function
timely
activation
E3
ligase
APC/C.
Pocket
integrity
APC/C
phosphorylation
particularly
at
non-consensus
CDK1
sites
full
vitro
ubiquitylation
activity.
Our
results
support
model
B1’s
facilitates
sequential
phosphorylations
involving
initial
priming
events
assist
subsequent
pocket-dependent
even
motifs.
Nature Communications,
Год журнала:
2025,
Номер
16(1)
Опубликована: Май 8, 2025
Abstract
Cell
cycle
progression
is
governed
by
complexes
of
the
cyclin-dependent
kinases
(CDKs)
and
their
regulatory
subunits
cyclin
Cks1.
CDKs
phosphorylate
hundreds
substrates,
often
at
multiple
sites.
Multisite
phosphorylation
depends
on
Cks1,
which
binds
initial
priming
sites
to
promote
secondary
other
Here,
we
describe
a
similar
role
for
recently
discovered
phosphate-binding
pocket
(PP)
B-type
cyclins.
Mutation
PP
in
Clb2,
major
mitotic
budding
yeast,
alters
bud
morphology
delays
onset
anaphase.
reduces
multi-site
CDK
substrates
vitro,
including
Cdc16
Cdc27
anaphase-promoting
complex/cyclosome
Bud6
Spa2
polarisome.
We
conclude
that
PP,
like
controls
pattern
multisite
thereby
helping
establish
robust
timing
cell-cycle
events.
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2024,
Номер
unknown
Опубликована: Фев. 29, 2024
Summary
Cell
cycle
progression
is
governed
by
complexes
of
the
cyclin-dependent
kinases
(CDKs)
and
their
regulatory
subunits
cyclin
Cks1.
CDKs
phosphorylate
hundreds
substrates,
often
at
multiple
sites.
Multisite
phosphorylation
depends
on
Cks1,
which
binds
initial
priming
sites
to
promote
secondary
other
Here,
we
describe
a
similar
role
for
recently
discovered
phosphate-binding
pocket
(PP)
B-type
cyclins.
Mutation
PP
in
Clb2,
major
mitotic
budding
yeast,
alters
bud
morphology
delays
onset
anaphase.
Using
phosphoproteomics
vivo
kinase
reactions
vitro
,
find
that
mutation
reduces
several
CDK
including
Bud6
subunit
polarisome
Cdc16
Cdc27
anaphase-promoting
complex/cyclosome.
We
conclude
PP,
like
controls
timing
multisite
thereby
helping
establish
robust
cell-cycle
events.
International Journal of Molecular Sciences,
Год журнала:
2025,
Номер
26(8), С. 3534 - 3534
Опубликована: Апрель 9, 2025
The
cell
wall
integrity
(CWI)
pathway
is
responsible
for
transcriptional
regulation
of
remodeling
in
response
to
stress.
How
mediated
by
the
CWI
effected
inputs
from
other
signaling
pathways
not
well
understood.
Here,
we
demonstrate
that
Mck1
kinase
cooperates
with
Slt2,
MAP
pathway,
promote
thickening
glucose-starved
cells.
Integrative
analyses
transcriptome,
proteome
and
metabolic
profiling
indicate
required
accumulation
UDP-glucose
(UDPG),
substrate
β-glucan
synthesis,
through
activation
two
regulons:
Msn2/4-dependent
stress
Cat8-/Adr1-mediated
reprogram
dependent
on
SNF1
complex.
Analysis
phosphoproteome
suggests
similar
mammalian
Gsk-3
kinases,
involved
cytoskeleton-dependent
cellular
processes,
metabolism,
transcription.
Specifically,
may
be
implicated
Snf1-dependent
PKA
inhibition
SAGA
(Spt-Ada-Gcn5
acetyltransferase)-mediated
transcription
activation,
a
hypothesis
further
underscored
significant
overlap
between
Mck1-
Gcn5-activated
transcriptomes.
Phenotypic
analysis
also
supports
roles
actin
cytoskeleton-mediated
exocytosis
ensure
plasma
membrane
homeostasis
wall-stressed
Together,
these
findings
only
reveal
novel
functions
reprogramming
polarized
growth
but
provide
valuable
omics
resources
future
studies
uncover
underlying
mechanisms
kinases
response.
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2024,
Номер
unknown
Опубликована: Июнь 3, 2024
Abstract
Protein-protein
interaction
sites
(PPIs)
are
potentially
more
selective
therapeutic
binding
than
protein
substrate
sites.
PPIs
include
distinct
regions
frequently
called
“hotspots,”
of
key
amino
acid
interactions.
Prospective
identification
these
hotspots
through
X-ray
crystallographic
screening
could
assist
in
the
separation
function
mutants
for
experimental
validation,
enhance
confidence
AI-generated
multiprotein
complex
predictions
and
accelerate
development
chemical
probes.
To
explore
applications,
we
utilize
FragLite
library
to
examine
surfaces
CDK2-cyclin
A.
The
many
protein-
peptide-CDK2-cyclin
A
complexes
that
have
been
structurally
characterised
make
this
an
appropriate
test
case.
We
show
FragLites
comprehensively
map
both
known
protein-protein
on
identify
a
possible
uncharacterised
site,
providing
structural
method
toward
directing
mechanistic
studies
starting
points
probe
design.
Molecular and Cellular Biology,
Год журнала:
2024,
Номер
44(7), С. 289 - 301
Опубликована: Июнь 12, 2024
The
human
Origin
Recognition
Complex
(ORC)
is
required
not
only
for
the
initiation
of
DNA
replication,
but
also
implicated
in
diverse
cellular
functions,
including
chromatin
organization,
centrosome
biology,
and
cytokinesis.
smallest
subunit
ORC,
Orc6,
poorly
conserved
amongst
eukaryotes.
Recent
studies
from
our
laboratory
have
suggested
that
Orc6
replication
licensing,
needed
S-phase
progression.
Further,
ATR-dependent
phosphorylation
at
T229
damage
response
during
S-phase.
In
this
study,
we
demonstrate
CDK-dependent
T195
occurs
mitosis.
While
does
seem
to
be
exit
mitosis,
cells
expressing
phosphomimetic
T195E
mutant
impede
Moreover,
phosphorylated
form
associates
with
ORC
more
robustly,
shows
enhanced
association
outside
G1,
supporting
view
may
prevent
role
Orc1-5
licensing
G1.
Finally,
localize
nucleolar
organizing
centers
regulate
ribosome
biogenesis.
Our
results
suggest
prevents
replication.
The Journal of Cell Biology,
Год журнала:
2024,
Номер
223(11)
Опубликована: Авг. 6, 2024
Mitosis
in
early
embryos
often
proceeds
at
a
rapid
pace,
but
how
this
pace
is
achieved
not
understood.
Here,
we
show
that
cyclin
B3
the
dominant
driver
of
embryonic
mitoses
C.
elegans
embryo.
Cyclins
B1
and
B2
support
slow
mitosis
(NEBD
to
anaphase
∼600
s),
presence
dominantly
drives
approximately
threefold
faster
observed
wildtype.
Multiple
mitotic
events
are
slowed
down
B2-driven
mitosis,
B3-associated
Cdk1
H1
kinase
activity
∼25-fold
more
active
than
B1-associated
Cdk1.
Addition
fast
B3-only
introduces
an
∼60-s
delay
between
completion
chromosome
alignment
onset;
delay,
which
important
for
segregation
fidelity,
dependent
on
inhibitory
phosphorylation
activator
Cdc20.
Thus,
dominance,
coupled
B1-dependent
acts
via
Cdc20
phosphorylation,
sets
ensures
fidelity
