Current Opinion in Genetics & Development,
Год журнала:
2024,
Номер
86, С. 102201 - 102201
Опубликована: Май 2, 2024
Polycomb-associated
chromatin
and
pericentromeric
heterochromatin
form
genomic
domains
important
for
the
epigenetic
regulation
of
gene
expression.
Both
Polycomb
complexes
factors
rely
on
'read
write'
mechanisms,
which,
their
own,
are
not
sufficient
to
explain
formation
maintenance
these
domains.
Microscopy
has
revealed
that
they
specific
nuclear
compartments
separated
from
rest
genome.
Recently,
some
subunits
molecular
machineries
have
been
shown
undergo
phase
separation,
both
in
vitro
vivo,
suggesting
separation
might
play
roles
function
two
kinds
repressive
chromatin.
In
this
review,
we
will
present
recent
advances
field
facultative
constitutive
through
separation.
Abstract
PomBase
(https://www.pombase.org),
the
model
organism
database
(MOD)
for
fission
yeast,
was
recently
awarded
Global
Core
Biodata
Resource
(GCBR)
status
by
Coalition
(GBC;
https://globalbiodata.org/)
after
a
rigorous
selection
process.
In
this
MOD
review,
we
present
PomBase’s
continuing
growth
and
improvement
over
last
2
years.
We
describe
these
improvements
in
context
of
qualitative
GCBR
indicators
related
to
scientific
quality,
comprehensivity,
accelerating
science,
user
stories,
collaborations
with
other
biodata
resources.
This
review
also
showcases
depth
existing
connections
both
within
biocuration
ecosystem
between
its
community.
Communications Biology,
Год журнала:
2024,
Номер
7(1)
Опубликована: Март 1, 2024
Abstract
Tau
is
a
microtubule-associated
protein
often
found
in
neurofibrillary
tangles
(NFTs)
the
brains
of
patients
with
Alzheimer’s
disease.
Beyond
this
context,
mounting
evidence
suggests
that
tau
localizes
into
nucleus,
where
it
may
play
role
DNA
protection
and
heterochromatin
regulation.
The
molecular
mechanisms
behind
these
observations
are
currently
unclear.
Using
vitro
biophysical
experiments,
here
we
demonstrate
can
undergo
liquid-liquid
phase
separation
(LLPS)
DNA,
mononucleosomes,
reconstituted
nucleosome
arrays
under
low
salt
conditions.
Low
concentrations
promote
chromatin
compaction
protect
from
digestion.
While
material
state
samples
at
physiological
dominated
by
oligomerization,
still
associate
strongly
reversibly
arrays.
These
properties
driven
tau’s
strong
interactions
linker
nucleosomal
DNA.
In
addition,
co-localizes
droplets
formed
phosphorylated
HP1α,
key
constituent
thought
to
function
through
an
LLPS
mechanism.
Importantly,
disrupted
aberrant
hyperphosphorylation.
suggest
directly
impact
accessibility
loss
could
contribute
nuclear
effects
seen
pathology.
Proceedings of the National Academy of Sciences,
Год журнала:
2024,
Номер
121(6)
Опубликована: Янв. 29, 2024
Heterochromatin,
defined
by
histone
H3
lysine
9
methylation
(H3K9me),
spreads
across
large
domains
and
can
be
epigenetically
inherited
in
a
self-propagating
manner.
Heterochromatin
propagation
depends
upon
read–write
mechanism,
where
the
Clr4/Suv39h
methyltransferase
binds
to
preexisting
trimethylated
H3K9
(H3K9me3)
further
deposits
H3K9me.
How
parental
methylated
template
is
preserved
during
DNA
replication
not
well
understood.
Here,
we
demonstrate
using
Schizosaccharomyces
pombe
that
heterochromatic
regions
are
specialized
demarcated
their
surrounding
boundary
elements.
throughout
these
distinguished
an
abundance
of
replisome
components
coordinated
Swi6/HP1.
Although
mutations
replicative
helicase
subunit
Mcm2
affect
binding
impede
maintenance
heterochromatin
domain
at
artificially
targeted
ectopic
site,
they
have
only
modest
impact
on
via
mechanism
endogenous
site.
Instead,
our
findings
suggest
crucial
role
for
factor
Mcl1
retaining
histones
promoting
involving
chaperone
FACT.
Engagement
FACT
with
requires
elements,
which
position
nuclear
peripheral
subdomain
enriched
factors.
Our
highlight
importance
elements
creating
environment
retention
histones,
facilitates
epigenetic
inheritance
heterochromatin.
Cell
memory
refers
to
the
capacity
of
cells
maintain
their
gene
expression
program
once
initiating
environmental
signal
has
ceased.
This
exceptional
feature
is
key
during
formation
mammalian
organisms,
and
it
believed
be
in
part
mediated
by
epigenetic
factors
that
can
endorse
with
landmarks
required
transcriptional
programs
upon
cell
duplication.
Here,
we
review
current
literature
analyzing
molecular
basis
mammals,
a
focus
on
mechanisms
which
transcriptionally
repressive
chromatin
modifications
such
as
methylation
DNA
histone
H3
are
propagated
through
mitotic
divisions.
The
emerging
picture
suggests
cellular
supported
an
cycle
reversible
activities
carried
out
regulators
coordination
transition
create
multiphasic
system
accommodate
both
maintenance
identity
differentiation
proliferating
stem
populations.
