bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2022,
Номер
unknown
Опубликована: Дек. 19, 2022
Abstract
Tomosyn
is
a
large,
non-canonical
SNARE
protein
proposed
to
act
as
competitive
inhibitor
of
complex
formation
in
vesicle
exocytosis.
In
the
brain,
tomosyn
inhibits
fusion
synaptic
vesicles
(SVs),
whereas
its
role
neuropeptide-containing
dense
core
(DCVs)
unknown.
Here,
we
addressed
this
question
using
new
mouse
model
allowing
conditional
deletion
(
Stxbp5
)
and
paralogue
tomosyn-2
Stxbp5l
),
an
assay
that
detects
DCV
exocytosis
with
single
resolution
primary
hippocampal
neurons.
Surprisingly,
loss
both
tomosyns
did
not
affect
but
resulted
strong
reduction
intracellular
levels
many
cargos,
most
prominently
brain-derived
neurotrophic
factor
(BDNF),
granin
VGF
prohormone
convertase
PCSK1.
Reduced
cargos
were
paralleled
by
decreased
size
impaired
mRNA
expression
corresponding
genes.
We
conclude
regulate
neuropeptide
neurotrophin
secretion
via
control
cargo
production,
at
step
release.
Our
findings
suggest
differential
effect
on
two
main
secretory
pathways
mammalian
neurons
argues
against
conserved
formation.
The Journal of Cell Biology,
Год журнала:
2023,
Номер
222(8)
Опубликована: Июнь 16, 2023
Intracellular
Zn2+
concentrations
increase
via
depolarization-mediated
influx
or
intracellular
release,
but
the
immediate
effects
of
signals
on
neuron
function
are
not
fully
understood.
By
simultaneous
recording
cytosolic
and
organelle
motility,
we
find
that
elevated
(IC50
≈
5–10
nM)
reduces
both
lysosomal
mitochondrial
motility
in
primary
rat
hippocampal
neurons
HeLa
cells.
Using
live-cell
confocal
microscopy
vitro
single-molecule
TIRF
imaging,
reveal
inhibits
activity
motor
proteins
(kinesin
dynein)
without
disrupting
their
microtubule
binding.
Instead,
directly
binds
to
microtubules
selectively
promotes
detachment
tau,
DCX,
MAP2C,
MAP1B,
MAP4,
MAP7,
MAP9,
p150glued.
Bioinformatic
predictions
structural
modeling
show
binding
sites
partially
overlap
with
dynein,
kinesin.
Our
results
intraneuronal
regulates
axonal
transport
microtubule-based
processes
by
interacting
microtubules.
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2024,
Номер
unknown
Опубликована: Май 9, 2024
Abstract
Neurons,
as
long-living
non-dividing
cells
with
complex
morphology,
depend
on
highly
elaborate
secretory
trafficking
system
which
ensures
the
constant
delivery,
removal
and
recycling
of
proteins
membranes.
Previously,
we
have
shown
that
simplified
Golgi-related
structures
called
Golgi
satellites
(GS),
distinct
from
somatic
complex,
are
present
in
dendrites
primary
hippocampal
neurons
involved
glycosylation
local
forward
membrane
proteins.
However,
whether
GS
also
targeted
to
axons
principal
not
been
explored.
Here,
investigate
subcellular
distribution
adult
discover
mobile
stationary
along
entire
axonal
length,
extending
distal
tips
growth
cone.
Live
imaging
experiments
revealed
neuronal
firing
modulates
switch
between
long
range
transport
mediated
by
kinesin
dynein
stalling.
We
found
frequently
pause
or
stop
at
pre-synaptic
sites
activity-dependent
manner.
This
behavior
depends
actin
cytoskeleton
actin-based
motor
protein
myosin
VI.
Overall,
our
study
demonstrates
activity
can
dynamically
regulate
positioning
axon,
shedding
light
intricate
mechanisms
underlying
organelle
neurons.
Significance
statement
Our
unveils
presence
dynamic
specialized
organelles
implicated
trafficking,
within
throughout
including
cone
regions.
transported
bidirectionally
their
preferential
pausing
presynaptic
is
regulated
firing.
boutons
relies
VI
protein.
work
elucidates
how
distribution,
fundamental
Dense
core
vesicles
(DCVs)
transport
and
release
various
neuropeptides
neurotrophins
that
control
diverse
brain
functions,
but
the
DCV
secretory
pathway
remains
poorly
understood.
Here,
we
tested
a
prediction
emerging
from
invertebrate
studies
about
crucial
role
of
intracellular
trafficking
GTPase
Rab10,
by
assessing
exocytosis
at
single-
cell
resolution
upon
acute
Rab10
depletion
in
mature
mouse
hippocampal
neurons,
to
circumvent
potential
confounding
effects
Rab10’s
established
neurite
outgrowth.We
observed
significant
inhibition
Rab10-depleted
whereas
synaptic
vesicle
was
unaffected.
However,
rather
than
direct
involvement
trafficking,
this
effect
attributed
two
ER-dependent
processes,
ER-regulated
Ca
2+
dynamics
protein
synthesis.
Gene
ontology
analysis
differentially
expressed
proteins
identified
substantial
alterations
ER/ribosomal
proteins,
including
-pump
SERCA2.
In
addition,
ER
morphology
were
altered,
levels
depleted
homeostasis
impaired
neurons.
entry
using
ionophore
still
triggered
less
exocytosis.
Instead,
leucine
supplementation,
which
enhances
synthesis,
largely
rescued
deficiency.
We
conclude
is
required
for
neuropeptide
maintaining
regulating
Furthermore,
appeared
more
dependent
on
(acute)
synthesis
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2022,
Номер
unknown
Опубликована: Дек. 19, 2022
Abstract
Tomosyn
is
a
large,
non-canonical
SNARE
protein
proposed
to
act
as
competitive
inhibitor
of
complex
formation
in
vesicle
exocytosis.
In
the
brain,
tomosyn
inhibits
fusion
synaptic
vesicles
(SVs),
whereas
its
role
neuropeptide-containing
dense
core
(DCVs)
unknown.
Here,
we
addressed
this
question
using
new
mouse
model
allowing
conditional
deletion
(
Stxbp5
)
and
paralogue
tomosyn-2
Stxbp5l
),
an
assay
that
detects
DCV
exocytosis
with
single
resolution
primary
hippocampal
neurons.
Surprisingly,
loss
both
tomosyns
did
not
affect
but
resulted
strong
reduction
intracellular
levels
many
cargos,
most
prominently
brain-derived
neurotrophic
factor
(BDNF),
granin
VGF
prohormone
convertase
PCSK1.
Reduced
cargos
were
paralleled
by
decreased
size
impaired
mRNA
expression
corresponding
genes.
We
conclude
regulate
neuropeptide
neurotrophin
secretion
via
control
cargo
production,
at
step
release.
Our
findings
suggest
differential
effect
on
two
main
secretory
pathways
mammalian
neurons
argues
against
conserved
formation.