The goal of this project is to describe a novel role for the RNA-binding protein Sam68 in synaptic transmission and plasticity. Sam68 is a member of the KH-domain containing family of proteins, which have been linked to the pathogenesis of several neurological disorders via their effects on synaptic transmission. For example, mutations in the KH-family member FMRP result in Fragile X Mental Retardation Syndrome, while mutations in the KH-family member QUAKING have been implicated in Schizophrenia. Two recent studies suggest that Sam68 is involved in the pathogenesis of Fragile X Tremor/Ataxia Syndrome, and Spinal Muscular Atrophy. Elucidation of Sam68's role in maintaining efficient synaptic transmission will provide valuable insights into how dysfunction of the family of KH-domain containing proteins, and Sam68 in particular, leads to neurological disease. Sam68 may serve dual roles at the synapse, first as a modulator of synaptic transmission through NMDA receptor trafficking, and second as a regulator of local protein synthesis at dendritic spines. This proposal includes training in a number of advanced laboratory skills in the fields of electrophysiology and molecular biology in order to conduct a detailed investigation of Sam68's role at the synapse. To study the effects of loss of Sam68 we will use in vivo molecular manipulations (e.g. viral injections), in addition to a complimentary set of experiments using a line of Sam68 null mice. We will examine the effect of loss of Sam68 on NMDA receptor trafficking using whole cell patch clamp recording and quantitative immunohistochemistry. We will examine the ability of Sam68 to regulate local protein synthesis at dendritic spines using fluorescence in situ hybridization, and the photoconvertable fluorescent protein Dendra2. Sam68 may represent a novel regulator of synaptic plasticity by participating in activity-dependent changes involving both receptor trafficking, and local protein synthesis.

Public Health Relevance

Neurological disorders may arise from inefficiencies in the mechanisms that ensure proper communication between neurons in the central nervous system. This project aims to understand the role of the RNA-binding protein Sam68 in ensuring proper neuronal transmission. Understanding this role will be helpful for guiding the development of therapies for neurological disorders resulting from dysfunction of Sam68 and related proteins.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Predoctoral Individual National Research Service Award (F31)
Project #
5F31NS073200-02
Application #
8213129
Study Section
NST-2 Subcommittee (NST)
Program Officer
Mamounas, Laura
Project Start
2010-12-21
Project End
2014-05-20
Budget Start
2011-12-21
Budget End
2012-12-20
Support Year
2
Fiscal Year
2012
Total Cost
$47,232
Indirect Cost
Name
Albert Einstein College of Medicine
Department
Neurosciences
Type
Schools of Medicine
DUNS #
110521739
City
Bronx
State
NY
Country
United States
Zip Code
10461
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Klein, Matthew E; Younts, Thomas J; Castillo, Pablo E et al. (2013) RNA-binding protein Sam68 controls synapse number and local ?-actin mRNA metabolism in dendrites. Proc Natl Acad Sci U S A 110:3125-30