Dynein and dynactin move long-range but are delivered separately to the axon tip
The Journal of Cell Biology,
Год журнала:
2024,
Номер
223(5)
Опубликована: Фев. 6, 2024
Axonal
transport
is
essential
for
neuronal
survival.
This
driven
by
microtubule
motors
including
dynein,
which
transports
cargo
from
the
axon
tip
back
to
cell
body.
function
requires
its
cofactor
dynactin
and
regulators
LIS1
NDEL1.
Due
difficulties
imaging
dynein
at
a
single-molecule
level,
it
unclear
how
this
motor
coordinate
along
length
of
axon.
Here,
we
use
neuron-inducible
human
stem
line
(NGN2-OPTi-OX)
endogenously
tag
components
visualize
them
near-single
molecule
regime.
In
retrograde
direction,
find
that
can
move
entire
(>500
µm).
Furthermore,
NDEL1
also
undergo
long-distance
movement,
despite
being
mainly
implicated
with
initiation
transport.
Intriguingly,
in
anterograde
dynein/LIS1
moves
faster
than
dynactin/NDEL1,
consistent
on
different
cargos.
Therefore,
neurons
ensure
efficient
holding
dynein/dynactin
cargos
over
long
distances
but
keeping
separate
until
required.
Язык: Английский
MINFLUX reveals dynein stepping in live neurons
Proceedings of the National Academy of Sciences,
Год журнала:
2024,
Номер
121(38)
Опубликована: Сен. 10, 2024
Dynein
is
the
primary
molecular
motor
responsible
for
retrograde
intracellular
transport
of
a
variety
cargoes,
performing
successive
nanometer-sized
steps
within
milliseconds.
Due
to
limited
spatiotemporal
precision
established
methods
tracking,
current
knowledge
dynein
stepping
essentially
slowed-down
measurements
in
vitro.
Here,
we
use
MINFLUX
fluorophore
localization
directly
track
CRISPR/Cas9-tagged
endogenous
with
nanometer/millisecond
living
neurons.
We
show
that
primarily
takes
8
nm
steps,
including
frequent
sideways
but
few
backward
steps.
Strikingly,
majority
direction
reversals
between
and
anterograde
movement
occurred
on
time
scale
single
(16
ms),
suggesting
rapid
regulatory
reversal
mechanism.
Tug-of-war-like
behavior
during
pauses
or
was
unexpectedly
rare.
By
analyzing
dwell
concluded
rate-limiting
process
underlies
mechanism,
likely
arising
from
just
one
adenosine
5′-triphosphate
hydrolysis
event
being
required
each
step.
Our
study
underscores
power
elucidate
changes
underlying
protein
function
cells.
Язык: Английский
Neural Tracing Protein‐Functionalized Nanoparticles Capable of Fast Retrograde Axonal Transport in Live Neurons
Small,
Год журнала:
2024,
Номер
unknown
Опубликована: Апрель 22, 2024
Neural
tracing
proteins
like
horseradish
peroxidase-conjugated
wheat
germ
agglutinin
(WGA-HRP)
can
target
the
central
nervous
system
(CNS)
through
anatomic
retrograde
transport
without
crossing
blood-brain
barrier
(BBB).
Conjugating
WGA-HRP
to
nanoparticles
may
enable
creation
of
BBB-bypassing
nanomedicine.
Microfluidics
and
two-photon
confocal
microscopy
is
applied
screen
nanocarriers
for
efficacy
gain
mechanistic
insights
into
their
interactions
with
neurons.
Protein
modification
gold
alters
cellular
uptake
at
axonal
terminal
activates
fast
transport.
Trajectory
analysis
individual
endosomes
carrying
reveals
a
run-and-pause
pattern
along
axon
WGA-HRP-conjugated
exhibiting
longer
run
duration
faster
instantaneous
velocity
than
those
nonconjugated
nanoparticles.
The
results
offer
explanation
different
dynamics
as
well
cell-based
functional
assay
neuron-targeted
goal
developing
nanomedicine
treatment
disorders.
Язык: Английский
MINFLUX Reveals Dynein Stepping in Live Neurons
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2024,
Номер
unknown
Опубликована: Май 23, 2024
Dynein
is
the
primary
molecular
motor
responsible
for
retrograde
intracellular
transport
of
a
variety
cargoes,
performing
successive
nanometer-sized
steps
within
milliseconds.
Due
to
limited
spatiotemporal
precision
established
methods
tracking,
current
knowledge
dynein
stepping
essentially
slowed-down
measurements
in
vitro.
Here,
we
use
MINFLUX
fluorophore
localization
directly
track
CRISPR/Cas9-tagged
endogenous
with
nanometer/millisecond
living
neurons.
We
show
that
primarily
takes
8
nm
steps,
including
frequent
sideways
but
few
backward
steps.
Strikingly,
majority
direction
reversals
between
and
anterograde
movement
occurred
on
time
scale
single
(16
ms),
suggesting
rapid
regulatory
reversal
mechanism.
Tug-of-war-like
behavior
during
pauses
or
was
unexpectedly
rare.
By
analyzing
dwell
concluded
rate-limiting
process
underlies
mechanism
whereby
consumes
one
adenosine
5’-triphosphate
(ATP)
per
step.
Our
study
underscores
power
elucidate
changes
underlying
protein
function
cells.
Язык: Английский
Episodic Transport of Protein Aggregates Achieves a Positive Size Selectivity in Aggresome Formation
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2024,
Номер
unknown
Опубликована: Авг. 7, 2024
Eukaryotic
cells
direct
toxic
misfolded
proteins
to
various
protein
quality
control
pathways
based
on
their
chemical
features
and
aggregation
status.
Aggregated
are
targeted
selective
autophagy
or
specifically
sequestered
into
the
"aggresome,"
a
perinuclear
inclusion
at
microtubule-organizing
center
(MTOC).
However,
mechanism
for
selectively
sequestering
aggregates
aggresome
remains
unclear.
To
investigate
formation,
we
reconstituted
MTOC-directed
aggregate
transport
in
Язык: Английский
Acidic pH of Early Endosomes Governs SARS-CoV-2 Transport in Host Cells
Journal of Biological Chemistry,
Год журнала:
2024,
Номер
unknown, С. 108144 - 108144
Опубликована: Дек. 1, 2024
Endocytosis
is
a
prominent
mechanism
for
SARS-CoV-2
entry
into
host
cells.
Upon
internalization
early
endosomes
(EEs),
the
virus
transported
to
late
(LEs),
where
acidic
conditions
facilitate
spike
protein
processing
and
viral
genome
release.
Dynein
kinesin
motors
drive
EE
transport
along
microtubules;
dynein
moves
EEs
perinuclear
region,
while
kinesins
direct
them
towards
plasma
membrane,
creating
tug-of-war
over
direction
of
transport.
Here,
we
identify
that
luminal
pH
key
factor
regulating
outcome
this
tug-of-war.
Among
known
endosomal
regulators,
only
sodium-proton
exchanger
NHE9
has
so
far
been
genetically
linked
severe
COVID-19
risk.
functions
as
proton
leak
pathway
specifically
on
endosomes.
We
show
limiting
acidification
by
increasing
expression
leads
decreased
infectivity
spike-bearing
in
Our
investigation
identified
membrane
lipid
phosphatidylinositol-3-phosphate
(PI3P)
link
between
changes
Normally,
mature,
PI3P
depletes.
However,
cells
with
high
expression,
persists
longer
EEs.
plays
pivotal
role
recruitment
motor
proteins
subsequent
movement
Consistently,
observed
mediated
alkalization
hindered
movement.
Specifically,
speed
run-length
were
negatively
impacted,
ultimately
leading
falling
off
microtubules
impairing
delivery
cargo
LEs.
thus
offers
unique
opportunity
viable
therapeutic
target
impede
cell
entry.
Язык: Английский
Molecular basis for the assembly of the dynein transport machinery on microtubules
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2024,
Номер
unknown
Опубликована: Дек. 30, 2024
Abstract
Cytoplasmic
dynein-1,
a
microtubule-based
motor
protein,
requires
dynactin
and
an
adaptor
to
form
the
processive
dynein-dynactin-adaptor
(DDA)
complex.
The
role
of
microtubules
in
DDA
assembly
has
been
elusive.
Here,
we
reveal
detailed
structural
insights
into
microtubule-mediated
using
cryo-electron
microscopy.
We
find
that
adaptor-independent
dynein-
complex
(DD)
predominantly
forms
on
intrinsic
2:1
stoichiometry,
induced
by
spontaneous
parallelization
dynein
upon
microtubule
binding.
Adaptors
can
squeeze
exchange
within
assembled
microtubule-bound
DD
complex,
which
is
enabled
relative
rotations
between
dynactin,
further
facilitated
light
intermediate
chains
assist
‘search’
mechanism.
Our
findings
elucidate
dynamic
adaptability
transport
machinery,
new
mode
for
motile
Язык: Английский