Behavioral state-dependent Ras signaling and AMPA-R trafficking

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Behavioral state-dependent Ras signaling and
AMPA-R trafficking J. Julius Zhu Department
of Pharmacology University of Virginia School of
Medicine  
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Glutamate receptors relay excitatory synaptic
transmission
Nature 375400 Nature Neurosci 5513
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AMPA receptor subunits
AMPA-R GluR1 GluR2 GluR2L GluR3 GluR4
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Delivering genes with Sindbis virus
GFP
Make virus carrying GluR-GFP and prepare slices

Inject virus extracellularly
Incubate 15 hrs
Biochemistry, Electrophysiology, EM and imaging
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Detecting delivery of recombinant receptor
Endogenous Receptors GluR2/X
Recombinant Receptors GluRX/X
X 1, 3, 4
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Model for AMPA receptor trafficking at synapses
Science 2841811 Science 2872262 Nature
Neurosci 31098 Cell 105331
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Ras and Rap signal delivery and removal of AMPA-Rs
Cell 110443 Neuron 39in press
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Significance

• This work will further our understanding of
  synaptic plasticity, by linking molecular
  signaling to plasticity.
• Clinical implications important for
  understanding and suggesting better treatments
  for many neurological diseases, such as

1. von Recklinghausen neurofibromatosis
(incidence 1/3000 individuals Cell 63851
Nature 403495).2. Schizophrenia (incidence
0.7 adults Psychiatry Res 6325).3. X-linked
mental retardation (incidence 1/3000 males
Nature 392923).4. Alzheimers disease
(incidence 10 over 65-year old gt50 over
85-year old Ann Neurol 30572).5. Tuberous
sclerosis (incidence 0.3 adults Hum Genet
10797).
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Ras-MEK-ERK and Pi3K-PKB signal delivery of GR1
and GR2L
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Structure of small GTPases
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Expression of active Ras mutants in CA1 neurons
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Expression of active Ras mutants in CA1 neurons
IAMPA ()
INMDA ()
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Activation of Ras pathways increases p-ERK or
p-PKB
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Activation of Ras pathways increases p-ERK or
p-PKB
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Ras-MEK-ERK and Pi3K-PKB signal delivery of GR1
and GR2L
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Expression of active Ras mutants in knockout mice
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Ras-MEK-ERK and PI3K-PKB target S845 S831 of GR1
Anti-p845-GluR1
Anti-p831-GluR1
Anti-GluR1
Anti-GluR1
Control
Control
Ras(G37)
Ras(C40)
Ras(G37)
Ras(C40)
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Ras-MEK-ERK and PI3K-PKB target S845 S831 of GR1
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Ras-MEK-ERK and Pi3K-PKB signal delivery of GR1
and GR2L
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LTP experimental configuration
Control pathway
Stimulated pathway
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Expression of Ras(G37)-GFP occludes 50 of LTP
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Expression of Ras(C40)-GFP occludes 50 of LTP
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Blocking Ras-MEK-ERK or Pi3K-PKB blocks 50 of LTP
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Ras-MEK-ERK and Pi3K-PKB signal delivery of GR1
and GR2L
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Synaptic delivery of GluR1 by neuromodulator
agonists
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Neuromodulator agonists stimulate Ras-MEK-ERK and
Pi3K-PKB
Anti-phospho-ERK1/2
Anti-phospho-PKB
Anti-ERK1/2
Anti-PKB
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Neuromodulator agonists stimulate Ras-MEK-ERK and
Pi3K-PKB
Control
CaMKII
Histamine
McN
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Ras-MEK-ERK and Pi3K-PKB signal delivery of GR1
and GR2L
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Synaptic delivery of GluR1 at different
behavioral states
IAMPA ()
INMDA ()
Control vs. GluR1ct-GFP
Control vs. GluR2Lct-GFP
Control vs. GluR1ct-GFP
Control vs. GluR2Lct-GFP
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Activation of Ras-MEK-ERK and Pi3K-PKB at
different states
Anti-phospho-ERK1/2
Anti-phospho-PKB
Anti-ERK1/2
Anti-PKB
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Activation of Ras-MEK-ERK and Pi3K-PKB at
different states
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Ras-MEK-ERK and Pi3K-PKB signal delivery of GR1
and GR2L
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Trafficking
Signaling

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Acknowledgements
Dept of Pharmacology, UVA Yi Qin, MD, MS
(UW-Madison) Joel Baumgart, BA, BS
(Missouri) Anders Killend, MS (Oslo) Hailan Hu,
PhD (HHMI/Berkeley) Yinghua Zhu, MD, MS
(Peking/CSHL)
Cold Spring Harbor Laboratory Roberto
Malinow Linda van Alest MPI Medical
Research Peter Seeburg Pavel Osten
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Behavioral state-dependent activation of Ras
signaling pathways and synaptic delivery of
AMPA-Rs Joel P. Baumgart1, Yi Qin1,2, Yinghua
Zhu1, Kenneth Seidenman2, Pavel Osten3, Peter H.
Seeburg3, Linda van Aelst2, Roberto Malinow2 and
J. Julius Zhu1 1Department of Pharmacology and
Neuroscience Training Program University of
Virginia School of Medicine, Charlottesville, VA
22908 2Cold Spring Harbor Laboratory, Cold Spring
Harbor, NY 11724 3Department of Molecular
Neurobiology, Max Planck Institute for Medical
Research, Heidelberg D-69120, Germany