bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2023,
Номер
unknown
Опубликована: Окт. 16, 2023
ABSTRACT
Neurotransmission
at
synapses
is
mediated
by
the
fusion
and
subsequent
endocytosis
of
synaptic
vesicle
membranes.
Actin
has
been
suggested
to
be
required
for
presynaptic
but
mechanisms
that
control
actin
polymerization
its
mode
action
within
nerve
terminals
remain
poorly
understood.
We
combine
optical
recordings
membrane
dynamics
ultrastructural
analysis
with
genetic
pharmacological
manipulations
demonstrate
controlled
regulatory
diaphanous-related
formins
mDia1/3
Rho
family
GTPase
signaling.
show
impaired
assembly
in
near
absence
reduced
RhoA
activity
partly
compensated
hyperactivation
Rac1.
Inhibition
Rac1
signaling
further
aggravates
elicited
loss
mDia1/3.
Our
data
suggest
interdependent
mDia1/3-Rho
pathways
cooperatively
act
facilitate
controlling
F-actin.
Neuron,
Год журнала:
2023,
Номер
111(24), С. 4006 - 4023.e10
Опубликована: Дек. 1, 2023
Phosphorylation
of
α-synuclein
at
the
serine-129
site
(α-syn
Ser129P)
is
an
established
pathologic
hallmark
synucleinopathies
and
a
therapeutic
target.
In
physiologic
states,
only
fraction
α-syn
phosphorylated
this
site,
most
studies
have
focused
on
roles
post-translational
modification.
We
found
that
unlike
wild-type
(WT)
α-syn,
which
widely
expressed
throughout
brain,
overall
pattern
Ser129P
restricted,
suggesting
intrinsic
regulation.
Surprisingly,
preventing
blocked
activity-dependent
synaptic
attenuation
by
α-syn—thought
to
reflect
its
normal
function.
Exploring
mechanisms,
we
neuronal
activity
augments
Ser129P,
trigger
for
protein-protein
interactions
are
necessary
mediating
function
synapse.
AlphaFold2-driven
modeling
membrane-binding
simulations
suggest
scenario
where
induces
conformational
changes
facilitate
with
binding
partners.
Our
experiments
offer
new
conceptual
platform
investigating
role
Ser129
in
synucleinopathies,
implications
drug
development.
Clathrin-mediated
endocytosis
has
characteristic
features
in
neuronal
dendrites
and
presynapses,
but
how
membrane
proteins
are
internalized
along
the
axon
shaft
remains
unclear.
We
focused
on
clathrin-coated
structures
initial
segment
(AIS)
their
relationship
to
periodic
actin-spectrin
scaffold
that
lines
axonal
plasma
membrane.
A
combination
of
super-resolution
microscopy
platinum-replica
electron
cultured
neurons
revealed
AIS
pits
form
within
“clearings”,
circular
areas
devoid
mesh.
Actin-spectrin
disorganization
increased
pit
formation.
Cargo
uptake
live-cell
imaging
showed
particularly
stable.
Neuronal
plasticity-inducing
stimulation
triggered
internalization
through
polymerization
branched
actin
around
them.
Thus,
spectrin
regulate
formation
scission
control
at
AIS.
ABSTRACT
Actin,
a
ubiquitous
and
highly
conserved
cytoskeletal
protein,
plays
pivotal
role
in
various
cellular
functions
such
as
structural
support,
facilitating
cell
motility,
contributing
to
the
dynamic
processes
of
synaptic
function.
Apart
from
its
established
inducing
morphological
changes,
recent
developments
field
indicate
an
active
involvement
actin
modulating
both
structure
function
pre‐
postsynaptic
terminals.
Within
presynapse,
it
is
involved
organization
trafficking
vesicles,
neurotransmitter
release.
In
postsynapse,
dynamically
modulates
dendritic
spines,
influencing
density
anchoring
receptors.
addition,
interplay
at
synapse
underscores
essential
regulating
neural
communication.
This
review
strives
offer
comprehensive
overview
advancements
understanding
multifaceted
cytoskeleton
functions.
By
emphasizing
aberrant
regulation,
we
aim
provide
valuable
insights
into
underlying
mechanisms
Alzheimer's
disease
pathophysiology.
Journal of Cell Science,
Год журнала:
2024,
Номер
137(20)
Опубликована: Май 1, 2024
ABSTRACT
Exocytosis
is
a
fundamental
process
used
by
eukaryotes
to
regulate
the
composition
of
plasma
membrane
and
facilitate
cell–cell
communication.
To
investigate
exocytosis
in
neuronal
morphogenesis,
previously
we
developed
computational
tools
with
graphical
user
interface
enable
automatic
detection
analysis
exocytic
events
from
fluorescence
timelapse
images.
Although
these
were
useful,
found
code
was
brittle
not
easily
adapted
different
experimental
conditions.
Here,
validated
robust
versatile
toolkit,
named
pHusion,
for
exocytosis,
written
ImageTank,
programming
language
that
combines
image
visualization
numerical
methods.
We
tested
pHusion
using
variety
imaging
modalities
pH-sensitive
fluorophores,
diverse
cell
types
various
markers,
generate
flexible
intuitive
package.
Using
this
system,
show
VAMP3-mediated
occurs
30-times
more
frequently
melanoma
cells
compared
primary
oligodendrocytes,
VAMP2-mediated
fusion
mature
rat
hippocampal
neurons
are
longer
lasting
than
those
immature
murine
cortical
neurons,
clustered
space
yet
random
time
developing
neurons.
Current Opinion in Cell Biology,
Год журнала:
2024,
Номер
89, С. 102394 - 102394
Опубликована: Июль 3, 2024
This
review
examines
the
dynamic
mechanisms
underlying
cellular
signaling,
communication,
and
adhesion
via
transient,
nano-scale,
liquid-like
molecular
assemblies
on
plasma
membrane
(PM).
Traditional
views
posit
that
stable,
solid-like
complexes
perform
these
functions.
However,
advanced
imaging
reveals
many
signaling
scaffolding
proteins
only
briefly
reside
in
micron-scale
protein
PM,
including
cell
structures
synapses,
are
likely
made
of
archipelagoes
nanoliquid
islands.
Borrowing
concept
liquid–liquid
phase
separation
to
form
biocondensates,
we
propose
nano-scale
oligomers
enabled
by
multiple
weak
but
specific
interactions
often
involving
intrinsically
disordered
regions.
The
signals
from
individual
would
occur
as
pulses.
Single-molecule
emerges
a
crucial
technique
for
characterizing
transient
suggesting
shift
toward
model
where
fluidity
underpins
signal
regulation
integration.
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2024,
Номер
unknown
Опубликована: Июль 20, 2024
Neuronal
communication
relies
on
precisely
maintained
synaptic
vesicle
(SV)
clusters,
which
assemble
via
liquid-liquid
phase
separation
(LLPS).
This
process
requires
synapsins,
the
major
phosphoproteins,
are
known
to
bind
actin.
The
reorganization
of
SVs,
synapsins
and
actin
is
a
hallmark
activity,
but
their
interplay
still
unclear.
Here
we
combined
reconstitution
approaches
super-resolution
imaging
dissect
roles
synapsin-SV
condensates
in
organization
presynaptic
cytoskeleton.
Our
data
indicate
that
LLPS
synapsin
initiates
polymerization,
allowing
for
SV:synapsin:actin
assemblies
facilitate
mesoscale
SV
clusters
along
axons
mimicking
native
both
lamprey
mammalian
synapses.
Understanding
relationship
between
network
synapsin-SVs
an
essential
building
block
roadmap
unravel
how
coordinated
neurotransmission
axon
enables
circuit
function
behavior.
Microscopy and Microanalysis,
Год журнала:
2025,
Номер
31(2)
Опубликована: Март 17, 2025
Abstract
Super-resolution
microscopy
techniques
have
accelerated
scientific
progress,
enabling
researchers
to
explore
cellular
structures
and
dynamics
with
unprecedented
detail.
This
review
highlights
the
most
recent
developments
in
commercially
available
super-resolution
microscopes,
focusing
on
widely
used
techniques:
confocal
laser
scanning
systems,
structured
illumination
(SIM),
stimulated
emission
depletion
(STED)
microscopy,
single-molecule
localization
(SMLM).
We
detail
technological
advancements
of
Confocal.NL's
GAIA,
Nikon's
NSPARC,
CSR
Biotech's
MI-SIM,
Zeiss's
Lattice
SIM
5,
Leica's
STELLARIS
STED,
abberior's
STED
MINFLUX
as
well
Abbelight's
SAFe
MN360
Bruker's
Vutara
VXL
SMLM
platforms.
These
address
need
for
enhanced
resolution,
reduced
phototoxicity,
improved
imaging
capabilities
a
range
sample
types,
while
also
aiming
enhance
user
friendliness.
Biosensors,
Год журнала:
2025,
Номер
15(5), С. 283 - 283
Опубликована: Апрель 30, 2025
Single-molecule
fluorescence
technology
stands
at
the
forefront
of
scientific
research
as
a
sophisticated
tool,
pushing
boundaries
our
understanding.
This
review
comprehensively
summarizes
technological
advancements
in
single-molecule
detection,
highlighting
latest
achievements
development
fluorescent
probes,
imaging
systems,
and
biosensors.
It
delves
into
applications
these
cutting-edge
tools
drug
discovery
neuroscience
research,
encompassing
design
monitoring
complex
delivery
elucidation
pharmacological
mechanisms
pharmacokinetics,
intricacies
neuronal
signaling
synaptic
function,
molecular
underpinnings
neurodegenerative
diseases.
The
exceptional
sensitivity
demonstrated
underscores
vast
potential
modern
biomedical
heralding
its
expansion
other
domains.
Neurotransmission
at
synapses
is
mediated
by
the
fusion
and
subsequent
endocytosis
of
synaptic
vesicle
membranes.
Actin
has
been
suggested
to
be
required
for
presynaptic
but
mechanisms
that
control
actin
polymerization
its
mode
action
within
nerve
terminals
remain
poorly
understood.
We
combine
optical
recordings
membrane
dynamics
ultrastructural
analysis
with
genetic
pharmacological
manipulations
demonstrate
controlled
regulatory
diaphanous-related
formins
mDia1/3
Rho
family
GTPase
signaling
in
mouse
hippocampal
neurons.
show
impaired
assembly
near
absence
reduced
RhoA
activity
partly
compensated
hyperactivation
Rac1.
Inhibition
Rac1
further
aggravates
elicited
loss
mDia1/3.
Our
data
suggest
interdependent
mDia1/3-Rho
pathways
cooperatively
act
facilitate
controlling
F-actin.
